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Obesity is a global health concern. Pregnancy has now been recognised as a critical time to affect the potential for life-long obesity risk in mother and child.1 The New Zealand Ministry of Health (MoH) has released the Childhood Obesity Plan.2 This document outlines 22 initiatives to support a reduction in obesity in children and young people up to 18 years of age in an endeavour to reduce the number of individuals who are obese when they enter adulthood, and are therefore more likely to carry this through life.2 Initiative number five of this document states that increased support should be offered regarding guidance for healthy weight gain in pregnancy. This recommendation is derived from evidence that women who gain excess weight in pregnancy are more likely to have overweight and obese children, irrespective of the environment in which they are raised, and that appropriate gestational weight gain can mitigate the impact of maternal overweight and obesity.1 Table 1: 2009 Institute of Medicine Guidelines for Healthy Weight Gain in Pregnancy.1 BMI (kg/m2) Recommended weight gain (kg) Underweight (<18.5) 12.5-18 Normal weight (18.5-24.9) 11.5-16 Overweight (25-29.9) 7-11.5 Obese (530) 5-9 The Childhood Obesity Plan references the 2014 MoH Guidance for Healthy Weight Gain in Pregnancy3 as the guiding document for initiative number five. The overarching guidelines held within this document recommend that women be advised and supported by their Lead Maternity Carer (LMC) who are primarily midwives to gain weight according to the 2009 Institute of Medicine (IoM) Guidelines for Healthy Weight Gain in Pregnancy (Table One).1 The IoM guidelines recommend weight gain based on pre-pregnancy, or early pregnancy BMI, and therefore rely on accurate knowledge of BMI, the absence of which may result in under- or over-estimation of recommended weight gain, and consequently, increased pregnancy risk.1Overweight and obese individuals today are more likely to consider themselves to be of normal weight than overweight and obese individuals 20 years ago,4 and individuals of all BMI groups are more likely to identify increased body size as normal,5 indicating an upward shift in the social norms of body habitus. Women of childbearing age are particularly susceptible to misperception of their own body weight, with estimates suggesting nearly 25% of overweight women underestimate their own weight.6 Further, there is evidence to suggest that women are not having their weight and height routinely and accurately measured in pregnancy,7 and there are discrepancies in the knowledge and practices of LMCs related to weight gain in pregnancy.8The aim of this study was to investigate pregnant women s knowledge of their BMI and gestational weight gain guidelines.MethodsParticipants were taking part in two larger studies. The first (the Christchurch cohort) aimed to describe women s knowledge and perceptions of the risks of excess weight in pregnancy, and the second, factors related to intuitive eating in pregnancy (the Dunedin cohort). Both studies collected identical data related to perceived BMI and weight gain recommendations and measured the height and weight of all participants who consented. All women participating in the Dunedin and the Christchurch studies were included.Recruitment was undertaken at four community radiology centres in Christchurch (in 2011), and one in Dunedin (in 2013-2015). Participants were recruited when attending their nuchal translucency (NT) scan at between 11 weeks and 13 weeks, 6-days gestation. Inclusion criterion included: the ability to read and write in English; consent to having height and weight measured; and additionally, for the Christchurch Cohort only, presenting with a completed Maternal Serum Screening in the First Trimester (MSS-1) form. Once recruited, participants were weighed on calibrated SECA 813 electronic scales, and had their height measured using SECA 206 or SECA 217 stadiometers. Instruction on the correct use of both the scales and stadiometers was provided by research staff according to instructions given in the 2008/09 Adult Nutrition Survey (Accessed at: www.health.govt.nz/publication/methodology-report-2008-09-nz-adult-nutrition-survey, page 28). Weight and height measurements were taken once and measurements were recorded to two decimal places. BMI was calculated as: weight (kg)/height2 (m2).To assess knowledge of appropriate weight gain for pregnancy, six options were posed by way of a paper-based, tick box survey completed by participants, including the 2009 IoM weight gain in pregnancy guidelines (Table One) and the options, I should not gain any weight in my pregnancy, plus It does not matter how much weight I gain. To assess perceived BMI, participants were asked, What weight do you consider yourself? with the options: underweight; normal weight; overweight; and obese. Education level was assessed via the options: attended high school; completed NCEA/Bursary or equivalent; trade certificate or similar; and university or tertiary institute degree or higher. Ethnicity was established in accordance with the New Zealand Census, and ethnicity was self-reported. Free text was offered for parity and gestation. Gestation was asked to the Christchurch cohort as How many weeks pregnant are you?, and was established from the estimated date of delivery on the NT scan for the Dunedin cohort.Stata 13.1 (StataCorp, Texas) was used for all statistical analyses. Contingency tables were constructed to compare actual versus perceived BMI category. From this, proportions were calculated of those that: accurately perceived their BMI category; overestimated their BMI category; and underestimated their BMI category. A similar process was used for the gestational weight gain recommendations. A kappa statistic was also calculated as a chance-adjusted measure of agreement for accurate identification of BMI category.As very few women overestimated their BMI category, only demographic predictors of underestimating BMI category were examined. Multivariate logistic regression was used to determine the odds ratio of underestimating BMI category compared to accurately identifying their BMI category. The demographic predictor variables were: BMI category; age; education; ethnicity; and study location, and these were all mutually adjusted for each other. The same analysis was run for actual BMI values (without adjustment for BMI category). As the BMI distribution exhibited positive-skew, geometric means (95% confidence interval) are presented for descriptive purposes. Odds ratios, 95% confidence intervals, and p-values were calculated. The same method was undertaken to determine demographic predictors for both underestimating and overestimating gestational weight gain recommendations. Models were checked by the Hosmer-Lemeshow goodness of fit test with 10 groups.Ethical approval for the Christchurch cohort was granted by the Upper South Island B Regional Ethics Committee (Ethics Reference: URB/11/EXP/032). Ethical approval for the Dunedin cohort was gained from the University of Otago Health Ethics Committee (Ethics Reference: 12/308).ResultsWhile 667 participants were recruited, only 644 agreed to have their weight and height measured and were therefore included in this analysis. The Dunedin cohort contributed 260 (40%) participants, and 384 (60%) were from the Christchurch cohort. The average age of participants was 31.2 years (range 18.2-49.9 years, Table 2), and the average gestation, 12.9 weeks. The majority of participants (76%) were of New Zealand European ethnicity. Participants were, in general, highly educated with 63% reporting a tertiary degree as their highest level of education, however one-fifth of the sample had not completed high school. Overall, 46% of participants were overweight (30% BMI 25-29.9 and 16% BMI>30).Table 2: Demographic characteristics (mean (SD)/n (%)). Christchurch n=384 Dunedin n=260 All n=644 Age (years) 30.9 (5.3) 31.6 (4.9) 31.2 (5.2) Gestation (weeks) 12.0 (0.5) 14.1 (0.7) 12.9 (1.2) Parity1 1 (0, 1) 1 (0, 1) 1 (0, 1) Ethnicity2 NZ European 289 (77) 191 (74) 480 (76) M\u0101ori 17 (5) 12 (5) 30 (5) Pacific Island 5 (1) 3 (1) 8 (1) Other 64 (17) 53 (20) 117 (18) Education3 Did not complete high school 96 (25) 31 (12) 127 (20) Completed high school/trade certificate or diploma 71 (19) 40 (16) 111 (17) Tertiary degree 211 (56) 187 (72) 398 (63) BMI category Underweight (BMI<18.5) 7 (2) 0 7 (1) Normal weight (BMI=18.5-24.9) 201 (52) 141 (54) 342 (53) Overweight (BMI=25-29.9) 106 (28) 85 (33) 191 (30) Obese (BMI 530) 70 (18) 34 (13) 104 (16) 1=median (IQR); 2=Nine participants gave no response when asked their ethnicity from the Christchurch cohort (2%) and one participant gave no response from the Dunedin cohort (0.4%), Others included European (52), Asian (30), American (12), Indian (8), African (7), Australian (3), Russian (2), and three unknowns; 3=Eight participants gave no response when asked their education level, six from the Christchurch cohort (2%) and 2 from the Dunedin cohort (0.8%).Six participants did not respond to the questions regarding the perception of their BMI category, four from the Christchurch cohort and two from the Dunedin cohort. More than half the sample (66%) accurately reported their BMI category (Table 3). Nearly one-third of the sample (31%) underestimated their BMI category, while only 3% (n=16) overestimated their BMI category, and one-quarter of these women were underweight. The kappa statistic=0.39, indicated fair agreement9 between perceived and actual BMI category.Table 3: Perceived versus actual BMI category, n (%). Measured BMI category Perceived underweight Perceived normal weight Perceived overweight Perceived obese Underweight 3 (0.5) 4 (0.6) 0 0 Normal weight 6 (0.9) 322 (50) 12 (2) 0 Overweight 1 (0.2) 103 (16) 83 (13) 0 Obese 0 14 (2) 74 (12) 16 (3) Total (n=638)1 10 (2) 443 (69) 169 (26) 16 (3) 1Six participants did not answer this question, n=4 from the Christchurch cohort and n=2 from the Dunedin cohortOverweight and obese women were much more likely to underestimate their BMI category than normal weight women (Table 4). For every BMI unit (kg/m2) higher, the odds that a woman underestimated her BMI category were 33% higher (p<0.001). After adjustment for other demographics, including BMI category, M\u0101ori and Pacific Island women were less likely to underestimate their BMI category compared to New Zealand European women (p=0.008). Age, education, and study location were not related to likelihood of underestimating BMI category (all p>0.05).Table 4:Demographic differences between those that accurately predicted BMI category and those that underestimated.1 Accurate2 n=421 Underestimated2 n=198 Odds ratio3 (95% CI) p-value BMI4, kg/m2 23.7 (23.4, 24.1) 29.2 (28.7, 29.8) 1.33 (1.26, 1.41) <0.001 BMI category, n (%) Normal weight (n=328) 322 (98) 6 (2) Reference - Overweight (n=187) 83 (44) 104 (56) 68.9 (28.9, 164.4) <0.001 Obese (n=104) 16 (15) 88 (85) 375.5 (136.2, 1035.1) <0.001 Age, years 31.3 (5.1) 31.0 (5.2) 0.98 (0.93, 1.03) 0.423 Education, n (%) Attended high school (n=121) 67 (55) 54 (45) Reference - Completed high school/trade certificate/diploma (n=109) 73 (67) 36 (33) 1.02 (0.46, 2.29) 0.960 Tertiary degree (n=382) 276 (72) 106 (28) 0.94 (0.49, 1.82) 0.865 Ethnicity, n (%) NZ European (n=463) 307 (66) 156 (34) Reference - M\u0101ori/PI (n=37) 23 (62) 14 (38) 0.29 (0.12, 0.73) 0.008 Others (n=110) 84 (76) 26 (24) 1.03 (0.50, 2.12) 0.946 Study, n (%) Christchurch (n=370) 246 (66) 124 (34) Reference - Dunedin (n=249) 175 (70) 74 (30) 0.75 (0.45, 1.25) 1=Underweight participants excluded;2=Mean (SD) presented unless otherwise indicated;3=Mutually adjusted for other variables presented (excluding BMI, which was adjusted for everything except BMI category);4=Geometric mean (95% CI) presentedTwenty-four participants did not respond to the question asking what they considered a healthy weight gain for their pregnancy to be, eight from Christchurch (2%) and 16 from Dunedin (6%). One hundred and ninety-eight women (31%) identified the correct gestational weight gain recommendation for their pregnancy (Table 5). Eight percent of the women (n=50) reported that it did not matter how much weight they gained the majority of these were of normal weight (n=28). Only four women answered that they thought that they should not gain any weight; three of these women were overweight and one was obese.Table 5: Accuracy in identification of gestational weight gain recommendation. What do you consider to be a healthy weight gain for you in this pregnancy?, n (%) Underweight (n=7) Normal weight (n=329) Overweight (n=181) Obese (n=103) All (n=620)1 It does not matter how much I gain 1 (0.2) 28 (5) 13 (2) 8 (1) 50 (8) 12.5-18kg 2 (0.3) 36 (6) 17 (3) 8 (1) 63 (10) 11.5-16kg 0 88 (14) 39 (6) 12 (2) 139 (22) 7-11.5 kg 3 (0.5) 123 (20) 81 (13) 47 (8) 254 (41) 5-9kg 1 (0.2) 54 (9) 28 (5) 27 (4) 110 (18) I should not gain any weight 0 0 3 (0.5) 1 (0.2) 4 (0.7) 1Twenty-four participants did not answer this question, n=8 from the Christchurch cohort and n=16 from the Dunedin cohortThe average BMI of women who underestimated their gestational weight gain recommendation was 23 kg/m2, and this was significantly lower than that of women who accurately reported their gestational weight gain recommendation (BMI=25.7 kg/m2; p<0.001). Conversely, women who overestimated their gestational weight gain recommendation had a higher mean BMI than those women who were accurate (BMI=28.7kg/m2; p<0.001).Table 6: Demographic associations with over- or under-estimating gestational weight gain recommendations.Independent of BMI, younger women were less likely to underestimate their gestational weight gain recommendations (p=0.012), whereas women of other ethnicity (p=0.001) were more likely to underestimate their gestational weight gain recommendation compared to New Zealand European women.DiscussionThis study suggests that a third of pregnant women in New Zealand do not know their BMI category, and at least two-thirds do not know the recommended weight they should gain in pregnancy. Specifically, the higher a woman s BMI, the less likely she is to know her correct BMI status or recommended gestational weight gain. This is concerning, as women who are overweight and obese are at the highest risk for excess gestational weight gain.10,11 The World Health Organization reports that the obesity epidemic has the potential to negate many of the health benefits that have contributed to the increased longevity observed in the world.12 New Zealand has the third highest obesity rate in the OECD, and rates are rising amongst those from all demographic groups.13 Of particular concern are the increasing levels of obesity amongst children because of the lifelong increased risk of comorbidities that obesity predisposes to.12Research on the role that the foetal environment plays in the longer-term health of the offspring suggests obese mothers are more likely to have obese children, a worrying observation due to the potential to perpetuate the obesity epidemic.1,14-16 Our study identifies a further potential exacerbation of this effect due to the lack of maternal knowledge of their own BMI status and optimal weight gain. Other factors present in the foetal-neonatal period that have also been correlated with increased later-life obesity risk include small and large for gestational age, gestational diabetes (GDM), maternal diabetes mellitus, excessive maternal gestational weight gain, and failure to breastfeed all of which more commonly occur in the overweight and obese mother, further compounding the risk of future obesity.1In view of this, management of gestational weight gain has been suggested as an important time to intervene medically. There is evidence that interventions to optimise gestational weight gain are associated with a reduction in risk of pre-eclampsia, and trends towards a reduction in risk of GDM, gestational hypertension, preterm delivery, intrauterine foetal death and macrosomia.17This study indicates that education is required to support the MoH guidance. Previous studies have identified that in New Zealand, LMCs8,18 and general practitioners19 do not weigh women before and throughout pregnancy, inform women of their BMI and BMI classification, or advise on appropriate pregnancy weight gain based on the IoM guidelines. Without this, we are not providing the full package of education that women require to adequately follow the MoH gestational weight gain guidance.Study strengths and limitationsThis study obtained data from 644 women, and thus had a large sample size. Of note, our sample was non-representative of the general New Zealand population. Our participants were highly educated and did not represent an ethnically diverse population, and this may mean our results are not generalisable to the New Zealand population as a whole. Further, our sample included 30% overweight and 16% obese women, lower than the latest population estimates for overweight and obesity in females of 30% and 31%, respectively.13ConclusionThe most recent intervention put forth by the New Zealand MoH to reduce the impact of obesity during childhood is laudable. However, this study indicates that more education needs to be provided and emphasis given to weighing and measuring women, and also accurately advising them of their specific gestational weight gain targets, without this, we are not fulfilling our responsibilities as healthcare professionals, and essentially expecting women to \u2018fly blind .

Summary

Abstract

Aim

To investigate pregnant women s knowledge of their body mass index (BMI) and their knowledge of gestational weight gain guidelines.

Method

Participants were recruited when attending their nuchal translucency scan at between 11 and 13 weeks, 6-days gestation in Dunedin or Christchurch, New Zealand. Recruitment staff measured participants weight and height. By way of a self-administered, paper-based survey, participants were asked to identify their body size (including: underweight (BMI

Results

In total, 644 women were included. Sixty-six percent of these correctly identified their BMI category, however only 31% identified their correct gestational weight gain recommendation. Overweight and obese women were much more likely to underestimate their BMI than normal weight women (p

Conclusion

The present study indicates that New Zealand women, particularly those who are overweight and obese, lack accurate knowledge of their own body size, and this may lead to an under- or over-estimation of appropriate gestational weight gain, which may in turn lead to increased risk of poor health outcomes in pregnancy. Education strategies related to healthy weight gain in pregnancy are urgently required.

Author Information

'- Emma Jeffs, Medical Student, Department of Women s and Children s Health, Dunedin School of Medicine, Dunedin; Jillian J Haszard, Research Fellow (biostatistician), Department of Women s and Children s Health, Dunedin School of Medicine, Dunedin; Benj

Acknowledgements

- This study was funded by the University of Otago, Dunedin, New Zealand.-

Correspondence

Helen Paterson, Department of Women s and Children s Health, Dunedin School of Medicine, University of Otago, PO Box 913, Dunedin, New Zealand.

Correspondence Email

helen.paterson@otago.ac.nz

Competing Interests

XXX

'-- Institute of Medicine (IoM), National Research Council (NRC). Weight Gain During Pregnancy: Reexamining the Guidelines. Washington (DC), National Academies Press (US) 2009. Ministry of Health. Childhood Obesity Plan. Wellington, New Zealand:

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Obesity is a global health concern. Pregnancy has now been recognised as a critical time to affect the potential for life-long obesity risk in mother and child.1 The New Zealand Ministry of Health (MoH) has released the Childhood Obesity Plan.2 This document outlines 22 initiatives to support a reduction in obesity in children and young people up to 18 years of age in an endeavour to reduce the number of individuals who are obese when they enter adulthood, and are therefore more likely to carry this through life.2 Initiative number five of this document states that increased support should be offered regarding guidance for healthy weight gain in pregnancy. This recommendation is derived from evidence that women who gain excess weight in pregnancy are more likely to have overweight and obese children, irrespective of the environment in which they are raised, and that appropriate gestational weight gain can mitigate the impact of maternal overweight and obesity.1 Table 1: 2009 Institute of Medicine Guidelines for Healthy Weight Gain in Pregnancy.1 BMI (kg/m2) Recommended weight gain (kg) Underweight (<18.5) 12.5-18 Normal weight (18.5-24.9) 11.5-16 Overweight (25-29.9) 7-11.5 Obese (530) 5-9 The Childhood Obesity Plan references the 2014 MoH Guidance for Healthy Weight Gain in Pregnancy3 as the guiding document for initiative number five. The overarching guidelines held within this document recommend that women be advised and supported by their Lead Maternity Carer (LMC) who are primarily midwives to gain weight according to the 2009 Institute of Medicine (IoM) Guidelines for Healthy Weight Gain in Pregnancy (Table One).1 The IoM guidelines recommend weight gain based on pre-pregnancy, or early pregnancy BMI, and therefore rely on accurate knowledge of BMI, the absence of which may result in under- or over-estimation of recommended weight gain, and consequently, increased pregnancy risk.1Overweight and obese individuals today are more likely to consider themselves to be of normal weight than overweight and obese individuals 20 years ago,4 and individuals of all BMI groups are more likely to identify increased body size as normal,5 indicating an upward shift in the social norms of body habitus. Women of childbearing age are particularly susceptible to misperception of their own body weight, with estimates suggesting nearly 25% of overweight women underestimate their own weight.6 Further, there is evidence to suggest that women are not having their weight and height routinely and accurately measured in pregnancy,7 and there are discrepancies in the knowledge and practices of LMCs related to weight gain in pregnancy.8The aim of this study was to investigate pregnant women s knowledge of their BMI and gestational weight gain guidelines.MethodsParticipants were taking part in two larger studies. The first (the Christchurch cohort) aimed to describe women s knowledge and perceptions of the risks of excess weight in pregnancy, and the second, factors related to intuitive eating in pregnancy (the Dunedin cohort). Both studies collected identical data related to perceived BMI and weight gain recommendations and measured the height and weight of all participants who consented. All women participating in the Dunedin and the Christchurch studies were included.Recruitment was undertaken at four community radiology centres in Christchurch (in 2011), and one in Dunedin (in 2013-2015). Participants were recruited when attending their nuchal translucency (NT) scan at between 11 weeks and 13 weeks, 6-days gestation. Inclusion criterion included: the ability to read and write in English; consent to having height and weight measured; and additionally, for the Christchurch Cohort only, presenting with a completed Maternal Serum Screening in the First Trimester (MSS-1) form. Once recruited, participants were weighed on calibrated SECA 813 electronic scales, and had their height measured using SECA 206 or SECA 217 stadiometers. Instruction on the correct use of both the scales and stadiometers was provided by research staff according to instructions given in the 2008/09 Adult Nutrition Survey (Accessed at: www.health.govt.nz/publication/methodology-report-2008-09-nz-adult-nutrition-survey, page 28). Weight and height measurements were taken once and measurements were recorded to two decimal places. BMI was calculated as: weight (kg)/height2 (m2).To assess knowledge of appropriate weight gain for pregnancy, six options were posed by way of a paper-based, tick box survey completed by participants, including the 2009 IoM weight gain in pregnancy guidelines (Table One) and the options, I should not gain any weight in my pregnancy, plus It does not matter how much weight I gain. To assess perceived BMI, participants were asked, What weight do you consider yourself? with the options: underweight; normal weight; overweight; and obese. Education level was assessed via the options: attended high school; completed NCEA/Bursary or equivalent; trade certificate or similar; and university or tertiary institute degree or higher. Ethnicity was established in accordance with the New Zealand Census, and ethnicity was self-reported. Free text was offered for parity and gestation. Gestation was asked to the Christchurch cohort as How many weeks pregnant are you?, and was established from the estimated date of delivery on the NT scan for the Dunedin cohort.Stata 13.1 (StataCorp, Texas) was used for all statistical analyses. Contingency tables were constructed to compare actual versus perceived BMI category. From this, proportions were calculated of those that: accurately perceived their BMI category; overestimated their BMI category; and underestimated their BMI category. A similar process was used for the gestational weight gain recommendations. A kappa statistic was also calculated as a chance-adjusted measure of agreement for accurate identification of BMI category.As very few women overestimated their BMI category, only demographic predictors of underestimating BMI category were examined. Multivariate logistic regression was used to determine the odds ratio of underestimating BMI category compared to accurately identifying their BMI category. The demographic predictor variables were: BMI category; age; education; ethnicity; and study location, and these were all mutually adjusted for each other. The same analysis was run for actual BMI values (without adjustment for BMI category). As the BMI distribution exhibited positive-skew, geometric means (95% confidence interval) are presented for descriptive purposes. Odds ratios, 95% confidence intervals, and p-values were calculated. The same method was undertaken to determine demographic predictors for both underestimating and overestimating gestational weight gain recommendations. Models were checked by the Hosmer-Lemeshow goodness of fit test with 10 groups.Ethical approval for the Christchurch cohort was granted by the Upper South Island B Regional Ethics Committee (Ethics Reference: URB/11/EXP/032). Ethical approval for the Dunedin cohort was gained from the University of Otago Health Ethics Committee (Ethics Reference: 12/308).ResultsWhile 667 participants were recruited, only 644 agreed to have their weight and height measured and were therefore included in this analysis. The Dunedin cohort contributed 260 (40%) participants, and 384 (60%) were from the Christchurch cohort. The average age of participants was 31.2 years (range 18.2-49.9 years, Table 2), and the average gestation, 12.9 weeks. The majority of participants (76%) were of New Zealand European ethnicity. Participants were, in general, highly educated with 63% reporting a tertiary degree as their highest level of education, however one-fifth of the sample had not completed high school. Overall, 46% of participants were overweight (30% BMI 25-29.9 and 16% BMI>30).Table 2: Demographic characteristics (mean (SD)/n (%)). Christchurch n=384 Dunedin n=260 All n=644 Age (years) 30.9 (5.3) 31.6 (4.9) 31.2 (5.2) Gestation (weeks) 12.0 (0.5) 14.1 (0.7) 12.9 (1.2) Parity1 1 (0, 1) 1 (0, 1) 1 (0, 1) Ethnicity2 NZ European 289 (77) 191 (74) 480 (76) M\u0101ori 17 (5) 12 (5) 30 (5) Pacific Island 5 (1) 3 (1) 8 (1) Other 64 (17) 53 (20) 117 (18) Education3 Did not complete high school 96 (25) 31 (12) 127 (20) Completed high school/trade certificate or diploma 71 (19) 40 (16) 111 (17) Tertiary degree 211 (56) 187 (72) 398 (63) BMI category Underweight (BMI<18.5) 7 (2) 0 7 (1) Normal weight (BMI=18.5-24.9) 201 (52) 141 (54) 342 (53) Overweight (BMI=25-29.9) 106 (28) 85 (33) 191 (30) Obese (BMI 530) 70 (18) 34 (13) 104 (16) 1=median (IQR); 2=Nine participants gave no response when asked their ethnicity from the Christchurch cohort (2%) and one participant gave no response from the Dunedin cohort (0.4%), Others included European (52), Asian (30), American (12), Indian (8), African (7), Australian (3), Russian (2), and three unknowns; 3=Eight participants gave no response when asked their education level, six from the Christchurch cohort (2%) and 2 from the Dunedin cohort (0.8%).Six participants did not respond to the questions regarding the perception of their BMI category, four from the Christchurch cohort and two from the Dunedin cohort. More than half the sample (66%) accurately reported their BMI category (Table 3). Nearly one-third of the sample (31%) underestimated their BMI category, while only 3% (n=16) overestimated their BMI category, and one-quarter of these women were underweight. The kappa statistic=0.39, indicated fair agreement9 between perceived and actual BMI category.Table 3: Perceived versus actual BMI category, n (%). Measured BMI category Perceived underweight Perceived normal weight Perceived overweight Perceived obese Underweight 3 (0.5) 4 (0.6) 0 0 Normal weight 6 (0.9) 322 (50) 12 (2) 0 Overweight 1 (0.2) 103 (16) 83 (13) 0 Obese 0 14 (2) 74 (12) 16 (3) Total (n=638)1 10 (2) 443 (69) 169 (26) 16 (3) 1Six participants did not answer this question, n=4 from the Christchurch cohort and n=2 from the Dunedin cohortOverweight and obese women were much more likely to underestimate their BMI category than normal weight women (Table 4). For every BMI unit (kg/m2) higher, the odds that a woman underestimated her BMI category were 33% higher (p<0.001). After adjustment for other demographics, including BMI category, M\u0101ori and Pacific Island women were less likely to underestimate their BMI category compared to New Zealand European women (p=0.008). Age, education, and study location were not related to likelihood of underestimating BMI category (all p>0.05).Table 4:Demographic differences between those that accurately predicted BMI category and those that underestimated.1 Accurate2 n=421 Underestimated2 n=198 Odds ratio3 (95% CI) p-value BMI4, kg/m2 23.7 (23.4, 24.1) 29.2 (28.7, 29.8) 1.33 (1.26, 1.41) <0.001 BMI category, n (%) Normal weight (n=328) 322 (98) 6 (2) Reference - Overweight (n=187) 83 (44) 104 (56) 68.9 (28.9, 164.4) <0.001 Obese (n=104) 16 (15) 88 (85) 375.5 (136.2, 1035.1) <0.001 Age, years 31.3 (5.1) 31.0 (5.2) 0.98 (0.93, 1.03) 0.423 Education, n (%) Attended high school (n=121) 67 (55) 54 (45) Reference - Completed high school/trade certificate/diploma (n=109) 73 (67) 36 (33) 1.02 (0.46, 2.29) 0.960 Tertiary degree (n=382) 276 (72) 106 (28) 0.94 (0.49, 1.82) 0.865 Ethnicity, n (%) NZ European (n=463) 307 (66) 156 (34) Reference - M\u0101ori/PI (n=37) 23 (62) 14 (38) 0.29 (0.12, 0.73) 0.008 Others (n=110) 84 (76) 26 (24) 1.03 (0.50, 2.12) 0.946 Study, n (%) Christchurch (n=370) 246 (66) 124 (34) Reference - Dunedin (n=249) 175 (70) 74 (30) 0.75 (0.45, 1.25) 1=Underweight participants excluded;2=Mean (SD) presented unless otherwise indicated;3=Mutually adjusted for other variables presented (excluding BMI, which was adjusted for everything except BMI category);4=Geometric mean (95% CI) presentedTwenty-four participants did not respond to the question asking what they considered a healthy weight gain for their pregnancy to be, eight from Christchurch (2%) and 16 from Dunedin (6%). One hundred and ninety-eight women (31%) identified the correct gestational weight gain recommendation for their pregnancy (Table 5). Eight percent of the women (n=50) reported that it did not matter how much weight they gained the majority of these were of normal weight (n=28). Only four women answered that they thought that they should not gain any weight; three of these women were overweight and one was obese.Table 5: Accuracy in identification of gestational weight gain recommendation. What do you consider to be a healthy weight gain for you in this pregnancy?, n (%) Underweight (n=7) Normal weight (n=329) Overweight (n=181) Obese (n=103) All (n=620)1 It does not matter how much I gain 1 (0.2) 28 (5) 13 (2) 8 (1) 50 (8) 12.5-18kg 2 (0.3) 36 (6) 17 (3) 8 (1) 63 (10) 11.5-16kg 0 88 (14) 39 (6) 12 (2) 139 (22) 7-11.5 kg 3 (0.5) 123 (20) 81 (13) 47 (8) 254 (41) 5-9kg 1 (0.2) 54 (9) 28 (5) 27 (4) 110 (18) I should not gain any weight 0 0 3 (0.5) 1 (0.2) 4 (0.7) 1Twenty-four participants did not answer this question, n=8 from the Christchurch cohort and n=16 from the Dunedin cohortThe average BMI of women who underestimated their gestational weight gain recommendation was 23 kg/m2, and this was significantly lower than that of women who accurately reported their gestational weight gain recommendation (BMI=25.7 kg/m2; p<0.001). Conversely, women who overestimated their gestational weight gain recommendation had a higher mean BMI than those women who were accurate (BMI=28.7kg/m2; p<0.001).Table 6: Demographic associations with over- or under-estimating gestational weight gain recommendations.Independent of BMI, younger women were less likely to underestimate their gestational weight gain recommendations (p=0.012), whereas women of other ethnicity (p=0.001) were more likely to underestimate their gestational weight gain recommendation compared to New Zealand European women.DiscussionThis study suggests that a third of pregnant women in New Zealand do not know their BMI category, and at least two-thirds do not know the recommended weight they should gain in pregnancy. Specifically, the higher a woman s BMI, the less likely she is to know her correct BMI status or recommended gestational weight gain. This is concerning, as women who are overweight and obese are at the highest risk for excess gestational weight gain.10,11 The World Health Organization reports that the obesity epidemic has the potential to negate many of the health benefits that have contributed to the increased longevity observed in the world.12 New Zealand has the third highest obesity rate in the OECD, and rates are rising amongst those from all demographic groups.13 Of particular concern are the increasing levels of obesity amongst children because of the lifelong increased risk of comorbidities that obesity predisposes to.12Research on the role that the foetal environment plays in the longer-term health of the offspring suggests obese mothers are more likely to have obese children, a worrying observation due to the potential to perpetuate the obesity epidemic.1,14-16 Our study identifies a further potential exacerbation of this effect due to the lack of maternal knowledge of their own BMI status and optimal weight gain. Other factors present in the foetal-neonatal period that have also been correlated with increased later-life obesity risk include small and large for gestational age, gestational diabetes (GDM), maternal diabetes mellitus, excessive maternal gestational weight gain, and failure to breastfeed all of which more commonly occur in the overweight and obese mother, further compounding the risk of future obesity.1In view of this, management of gestational weight gain has been suggested as an important time to intervene medically. There is evidence that interventions to optimise gestational weight gain are associated with a reduction in risk of pre-eclampsia, and trends towards a reduction in risk of GDM, gestational hypertension, preterm delivery, intrauterine foetal death and macrosomia.17This study indicates that education is required to support the MoH guidance. Previous studies have identified that in New Zealand, LMCs8,18 and general practitioners19 do not weigh women before and throughout pregnancy, inform women of their BMI and BMI classification, or advise on appropriate pregnancy weight gain based on the IoM guidelines. Without this, we are not providing the full package of education that women require to adequately follow the MoH gestational weight gain guidance.Study strengths and limitationsThis study obtained data from 644 women, and thus had a large sample size. Of note, our sample was non-representative of the general New Zealand population. Our participants were highly educated and did not represent an ethnically diverse population, and this may mean our results are not generalisable to the New Zealand population as a whole. Further, our sample included 30% overweight and 16% obese women, lower than the latest population estimates for overweight and obesity in females of 30% and 31%, respectively.13ConclusionThe most recent intervention put forth by the New Zealand MoH to reduce the impact of obesity during childhood is laudable. However, this study indicates that more education needs to be provided and emphasis given to weighing and measuring women, and also accurately advising them of their specific gestational weight gain targets, without this, we are not fulfilling our responsibilities as healthcare professionals, and essentially expecting women to \u2018fly blind .

Summary

Abstract

Aim

To investigate pregnant women s knowledge of their body mass index (BMI) and their knowledge of gestational weight gain guidelines.

Method

Participants were recruited when attending their nuchal translucency scan at between 11 and 13 weeks, 6-days gestation in Dunedin or Christchurch, New Zealand. Recruitment staff measured participants weight and height. By way of a self-administered, paper-based survey, participants were asked to identify their body size (including: underweight (BMI

Results

In total, 644 women were included. Sixty-six percent of these correctly identified their BMI category, however only 31% identified their correct gestational weight gain recommendation. Overweight and obese women were much more likely to underestimate their BMI than normal weight women (p

Conclusion

The present study indicates that New Zealand women, particularly those who are overweight and obese, lack accurate knowledge of their own body size, and this may lead to an under- or over-estimation of appropriate gestational weight gain, which may in turn lead to increased risk of poor health outcomes in pregnancy. Education strategies related to healthy weight gain in pregnancy are urgently required.

Author Information

'- Emma Jeffs, Medical Student, Department of Women s and Children s Health, Dunedin School of Medicine, Dunedin; Jillian J Haszard, Research Fellow (biostatistician), Department of Women s and Children s Health, Dunedin School of Medicine, Dunedin; Benj

Acknowledgements

- This study was funded by the University of Otago, Dunedin, New Zealand.-

Correspondence

Helen Paterson, Department of Women s and Children s Health, Dunedin School of Medicine, University of Otago, PO Box 913, Dunedin, New Zealand.

Correspondence Email

helen.paterson@otago.ac.nz

Competing Interests

XXX

'-- Institute of Medicine (IoM), National Research Council (NRC). Weight Gain During Pregnancy: Reexamining the Guidelines. Washington (DC), National Academies Press (US) 2009. Ministry of Health. Childhood Obesity Plan. Wellington, New Zealand:

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contact nzmj@nzma.org.nz

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Obesity is a global health concern. Pregnancy has now been recognised as a critical time to affect the potential for life-long obesity risk in mother and child.1 The New Zealand Ministry of Health (MoH) has released the Childhood Obesity Plan.2 This document outlines 22 initiatives to support a reduction in obesity in children and young people up to 18 years of age in an endeavour to reduce the number of individuals who are obese when they enter adulthood, and are therefore more likely to carry this through life.2 Initiative number five of this document states that increased support should be offered regarding guidance for healthy weight gain in pregnancy. This recommendation is derived from evidence that women who gain excess weight in pregnancy are more likely to have overweight and obese children, irrespective of the environment in which they are raised, and that appropriate gestational weight gain can mitigate the impact of maternal overweight and obesity.1 Table 1: 2009 Institute of Medicine Guidelines for Healthy Weight Gain in Pregnancy.1 BMI (kg/m2) Recommended weight gain (kg) Underweight (<18.5) 12.5-18 Normal weight (18.5-24.9) 11.5-16 Overweight (25-29.9) 7-11.5 Obese (530) 5-9 The Childhood Obesity Plan references the 2014 MoH Guidance for Healthy Weight Gain in Pregnancy3 as the guiding document for initiative number five. The overarching guidelines held within this document recommend that women be advised and supported by their Lead Maternity Carer (LMC) who are primarily midwives to gain weight according to the 2009 Institute of Medicine (IoM) Guidelines for Healthy Weight Gain in Pregnancy (Table One).1 The IoM guidelines recommend weight gain based on pre-pregnancy, or early pregnancy BMI, and therefore rely on accurate knowledge of BMI, the absence of which may result in under- or over-estimation of recommended weight gain, and consequently, increased pregnancy risk.1Overweight and obese individuals today are more likely to consider themselves to be of normal weight than overweight and obese individuals 20 years ago,4 and individuals of all BMI groups are more likely to identify increased body size as normal,5 indicating an upward shift in the social norms of body habitus. Women of childbearing age are particularly susceptible to misperception of their own body weight, with estimates suggesting nearly 25% of overweight women underestimate their own weight.6 Further, there is evidence to suggest that women are not having their weight and height routinely and accurately measured in pregnancy,7 and there are discrepancies in the knowledge and practices of LMCs related to weight gain in pregnancy.8The aim of this study was to investigate pregnant women s knowledge of their BMI and gestational weight gain guidelines.MethodsParticipants were taking part in two larger studies. The first (the Christchurch cohort) aimed to describe women s knowledge and perceptions of the risks of excess weight in pregnancy, and the second, factors related to intuitive eating in pregnancy (the Dunedin cohort). Both studies collected identical data related to perceived BMI and weight gain recommendations and measured the height and weight of all participants who consented. All women participating in the Dunedin and the Christchurch studies were included.Recruitment was undertaken at four community radiology centres in Christchurch (in 2011), and one in Dunedin (in 2013-2015). Participants were recruited when attending their nuchal translucency (NT) scan at between 11 weeks and 13 weeks, 6-days gestation. Inclusion criterion included: the ability to read and write in English; consent to having height and weight measured; and additionally, for the Christchurch Cohort only, presenting with a completed Maternal Serum Screening in the First Trimester (MSS-1) form. Once recruited, participants were weighed on calibrated SECA 813 electronic scales, and had their height measured using SECA 206 or SECA 217 stadiometers. Instruction on the correct use of both the scales and stadiometers was provided by research staff according to instructions given in the 2008/09 Adult Nutrition Survey (Accessed at: www.health.govt.nz/publication/methodology-report-2008-09-nz-adult-nutrition-survey, page 28). Weight and height measurements were taken once and measurements were recorded to two decimal places. BMI was calculated as: weight (kg)/height2 (m2).To assess knowledge of appropriate weight gain for pregnancy, six options were posed by way of a paper-based, tick box survey completed by participants, including the 2009 IoM weight gain in pregnancy guidelines (Table One) and the options, I should not gain any weight in my pregnancy, plus It does not matter how much weight I gain. To assess perceived BMI, participants were asked, What weight do you consider yourself? with the options: underweight; normal weight; overweight; and obese. Education level was assessed via the options: attended high school; completed NCEA/Bursary or equivalent; trade certificate or similar; and university or tertiary institute degree or higher. Ethnicity was established in accordance with the New Zealand Census, and ethnicity was self-reported. Free text was offered for parity and gestation. Gestation was asked to the Christchurch cohort as How many weeks pregnant are you?, and was established from the estimated date of delivery on the NT scan for the Dunedin cohort.Stata 13.1 (StataCorp, Texas) was used for all statistical analyses. Contingency tables were constructed to compare actual versus perceived BMI category. From this, proportions were calculated of those that: accurately perceived their BMI category; overestimated their BMI category; and underestimated their BMI category. A similar process was used for the gestational weight gain recommendations. A kappa statistic was also calculated as a chance-adjusted measure of agreement for accurate identification of BMI category.As very few women overestimated their BMI category, only demographic predictors of underestimating BMI category were examined. Multivariate logistic regression was used to determine the odds ratio of underestimating BMI category compared to accurately identifying their BMI category. The demographic predictor variables were: BMI category; age; education; ethnicity; and study location, and these were all mutually adjusted for each other. The same analysis was run for actual BMI values (without adjustment for BMI category). As the BMI distribution exhibited positive-skew, geometric means (95% confidence interval) are presented for descriptive purposes. Odds ratios, 95% confidence intervals, and p-values were calculated. The same method was undertaken to determine demographic predictors for both underestimating and overestimating gestational weight gain recommendations. Models were checked by the Hosmer-Lemeshow goodness of fit test with 10 groups.Ethical approval for the Christchurch cohort was granted by the Upper South Island B Regional Ethics Committee (Ethics Reference: URB/11/EXP/032). Ethical approval for the Dunedin cohort was gained from the University of Otago Health Ethics Committee (Ethics Reference: 12/308).ResultsWhile 667 participants were recruited, only 644 agreed to have their weight and height measured and were therefore included in this analysis. The Dunedin cohort contributed 260 (40%) participants, and 384 (60%) were from the Christchurch cohort. The average age of participants was 31.2 years (range 18.2-49.9 years, Table 2), and the average gestation, 12.9 weeks. The majority of participants (76%) were of New Zealand European ethnicity. Participants were, in general, highly educated with 63% reporting a tertiary degree as their highest level of education, however one-fifth of the sample had not completed high school. Overall, 46% of participants were overweight (30% BMI 25-29.9 and 16% BMI>30).Table 2: Demographic characteristics (mean (SD)/n (%)). Christchurch n=384 Dunedin n=260 All n=644 Age (years) 30.9 (5.3) 31.6 (4.9) 31.2 (5.2) Gestation (weeks) 12.0 (0.5) 14.1 (0.7) 12.9 (1.2) Parity1 1 (0, 1) 1 (0, 1) 1 (0, 1) Ethnicity2 NZ European 289 (77) 191 (74) 480 (76) M\u0101ori 17 (5) 12 (5) 30 (5) Pacific Island 5 (1) 3 (1) 8 (1) Other 64 (17) 53 (20) 117 (18) Education3 Did not complete high school 96 (25) 31 (12) 127 (20) Completed high school/trade certificate or diploma 71 (19) 40 (16) 111 (17) Tertiary degree 211 (56) 187 (72) 398 (63) BMI category Underweight (BMI<18.5) 7 (2) 0 7 (1) Normal weight (BMI=18.5-24.9) 201 (52) 141 (54) 342 (53) Overweight (BMI=25-29.9) 106 (28) 85 (33) 191 (30) Obese (BMI 530) 70 (18) 34 (13) 104 (16) 1=median (IQR); 2=Nine participants gave no response when asked their ethnicity from the Christchurch cohort (2%) and one participant gave no response from the Dunedin cohort (0.4%), Others included European (52), Asian (30), American (12), Indian (8), African (7), Australian (3), Russian (2), and three unknowns; 3=Eight participants gave no response when asked their education level, six from the Christchurch cohort (2%) and 2 from the Dunedin cohort (0.8%).Six participants did not respond to the questions regarding the perception of their BMI category, four from the Christchurch cohort and two from the Dunedin cohort. More than half the sample (66%) accurately reported their BMI category (Table 3). Nearly one-third of the sample (31%) underestimated their BMI category, while only 3% (n=16) overestimated their BMI category, and one-quarter of these women were underweight. The kappa statistic=0.39, indicated fair agreement9 between perceived and actual BMI category.Table 3: Perceived versus actual BMI category, n (%). Measured BMI category Perceived underweight Perceived normal weight Perceived overweight Perceived obese Underweight 3 (0.5) 4 (0.6) 0 0 Normal weight 6 (0.9) 322 (50) 12 (2) 0 Overweight 1 (0.2) 103 (16) 83 (13) 0 Obese 0 14 (2) 74 (12) 16 (3) Total (n=638)1 10 (2) 443 (69) 169 (26) 16 (3) 1Six participants did not answer this question, n=4 from the Christchurch cohort and n=2 from the Dunedin cohortOverweight and obese women were much more likely to underestimate their BMI category than normal weight women (Table 4). For every BMI unit (kg/m2) higher, the odds that a woman underestimated her BMI category were 33% higher (p<0.001). After adjustment for other demographics, including BMI category, M\u0101ori and Pacific Island women were less likely to underestimate their BMI category compared to New Zealand European women (p=0.008). Age, education, and study location were not related to likelihood of underestimating BMI category (all p>0.05).Table 4:Demographic differences between those that accurately predicted BMI category and those that underestimated.1 Accurate2 n=421 Underestimated2 n=198 Odds ratio3 (95% CI) p-value BMI4, kg/m2 23.7 (23.4, 24.1) 29.2 (28.7, 29.8) 1.33 (1.26, 1.41) <0.001 BMI category, n (%) Normal weight (n=328) 322 (98) 6 (2) Reference - Overweight (n=187) 83 (44) 104 (56) 68.9 (28.9, 164.4) <0.001 Obese (n=104) 16 (15) 88 (85) 375.5 (136.2, 1035.1) <0.001 Age, years 31.3 (5.1) 31.0 (5.2) 0.98 (0.93, 1.03) 0.423 Education, n (%) Attended high school (n=121) 67 (55) 54 (45) Reference - Completed high school/trade certificate/diploma (n=109) 73 (67) 36 (33) 1.02 (0.46, 2.29) 0.960 Tertiary degree (n=382) 276 (72) 106 (28) 0.94 (0.49, 1.82) 0.865 Ethnicity, n (%) NZ European (n=463) 307 (66) 156 (34) Reference - M\u0101ori/PI (n=37) 23 (62) 14 (38) 0.29 (0.12, 0.73) 0.008 Others (n=110) 84 (76) 26 (24) 1.03 (0.50, 2.12) 0.946 Study, n (%) Christchurch (n=370) 246 (66) 124 (34) Reference - Dunedin (n=249) 175 (70) 74 (30) 0.75 (0.45, 1.25) 1=Underweight participants excluded;2=Mean (SD) presented unless otherwise indicated;3=Mutually adjusted for other variables presented (excluding BMI, which was adjusted for everything except BMI category);4=Geometric mean (95% CI) presentedTwenty-four participants did not respond to the question asking what they considered a healthy weight gain for their pregnancy to be, eight from Christchurch (2%) and 16 from Dunedin (6%). One hundred and ninety-eight women (31%) identified the correct gestational weight gain recommendation for their pregnancy (Table 5). Eight percent of the women (n=50) reported that it did not matter how much weight they gained the majority of these were of normal weight (n=28). Only four women answered that they thought that they should not gain any weight; three of these women were overweight and one was obese.Table 5: Accuracy in identification of gestational weight gain recommendation. What do you consider to be a healthy weight gain for you in this pregnancy?, n (%) Underweight (n=7) Normal weight (n=329) Overweight (n=181) Obese (n=103) All (n=620)1 It does not matter how much I gain 1 (0.2) 28 (5) 13 (2) 8 (1) 50 (8) 12.5-18kg 2 (0.3) 36 (6) 17 (3) 8 (1) 63 (10) 11.5-16kg 0 88 (14) 39 (6) 12 (2) 139 (22) 7-11.5 kg 3 (0.5) 123 (20) 81 (13) 47 (8) 254 (41) 5-9kg 1 (0.2) 54 (9) 28 (5) 27 (4) 110 (18) I should not gain any weight 0 0 3 (0.5) 1 (0.2) 4 (0.7) 1Twenty-four participants did not answer this question, n=8 from the Christchurch cohort and n=16 from the Dunedin cohortThe average BMI of women who underestimated their gestational weight gain recommendation was 23 kg/m2, and this was significantly lower than that of women who accurately reported their gestational weight gain recommendation (BMI=25.7 kg/m2; p<0.001). Conversely, women who overestimated their gestational weight gain recommendation had a higher mean BMI than those women who were accurate (BMI=28.7kg/m2; p<0.001).Table 6: Demographic associations with over- or under-estimating gestational weight gain recommendations.Independent of BMI, younger women were less likely to underestimate their gestational weight gain recommendations (p=0.012), whereas women of other ethnicity (p=0.001) were more likely to underestimate their gestational weight gain recommendation compared to New Zealand European women.DiscussionThis study suggests that a third of pregnant women in New Zealand do not know their BMI category, and at least two-thirds do not know the recommended weight they should gain in pregnancy. Specifically, the higher a woman s BMI, the less likely she is to know her correct BMI status or recommended gestational weight gain. This is concerning, as women who are overweight and obese are at the highest risk for excess gestational weight gain.10,11 The World Health Organization reports that the obesity epidemic has the potential to negate many of the health benefits that have contributed to the increased longevity observed in the world.12 New Zealand has the third highest obesity rate in the OECD, and rates are rising amongst those from all demographic groups.13 Of particular concern are the increasing levels of obesity amongst children because of the lifelong increased risk of comorbidities that obesity predisposes to.12Research on the role that the foetal environment plays in the longer-term health of the offspring suggests obese mothers are more likely to have obese children, a worrying observation due to the potential to perpetuate the obesity epidemic.1,14-16 Our study identifies a further potential exacerbation of this effect due to the lack of maternal knowledge of their own BMI status and optimal weight gain. Other factors present in the foetal-neonatal period that have also been correlated with increased later-life obesity risk include small and large for gestational age, gestational diabetes (GDM), maternal diabetes mellitus, excessive maternal gestational weight gain, and failure to breastfeed all of which more commonly occur in the overweight and obese mother, further compounding the risk of future obesity.1In view of this, management of gestational weight gain has been suggested as an important time to intervene medically. There is evidence that interventions to optimise gestational weight gain are associated with a reduction in risk of pre-eclampsia, and trends towards a reduction in risk of GDM, gestational hypertension, preterm delivery, intrauterine foetal death and macrosomia.17This study indicates that education is required to support the MoH guidance. Previous studies have identified that in New Zealand, LMCs8,18 and general practitioners19 do not weigh women before and throughout pregnancy, inform women of their BMI and BMI classification, or advise on appropriate pregnancy weight gain based on the IoM guidelines. Without this, we are not providing the full package of education that women require to adequately follow the MoH gestational weight gain guidance.Study strengths and limitationsThis study obtained data from 644 women, and thus had a large sample size. Of note, our sample was non-representative of the general New Zealand population. Our participants were highly educated and did not represent an ethnically diverse population, and this may mean our results are not generalisable to the New Zealand population as a whole. Further, our sample included 30% overweight and 16% obese women, lower than the latest population estimates for overweight and obesity in females of 30% and 31%, respectively.13ConclusionThe most recent intervention put forth by the New Zealand MoH to reduce the impact of obesity during childhood is laudable. However, this study indicates that more education needs to be provided and emphasis given to weighing and measuring women, and also accurately advising them of their specific gestational weight gain targets, without this, we are not fulfilling our responsibilities as healthcare professionals, and essentially expecting women to \u2018fly blind .

Summary

Abstract

Aim

To investigate pregnant women s knowledge of their body mass index (BMI) and their knowledge of gestational weight gain guidelines.

Method

Participants were recruited when attending their nuchal translucency scan at between 11 and 13 weeks, 6-days gestation in Dunedin or Christchurch, New Zealand. Recruitment staff measured participants weight and height. By way of a self-administered, paper-based survey, participants were asked to identify their body size (including: underweight (BMI

Results

In total, 644 women were included. Sixty-six percent of these correctly identified their BMI category, however only 31% identified their correct gestational weight gain recommendation. Overweight and obese women were much more likely to underestimate their BMI than normal weight women (p

Conclusion

The present study indicates that New Zealand women, particularly those who are overweight and obese, lack accurate knowledge of their own body size, and this may lead to an under- or over-estimation of appropriate gestational weight gain, which may in turn lead to increased risk of poor health outcomes in pregnancy. Education strategies related to healthy weight gain in pregnancy are urgently required.

Author Information

'- Emma Jeffs, Medical Student, Department of Women s and Children s Health, Dunedin School of Medicine, Dunedin; Jillian J Haszard, Research Fellow (biostatistician), Department of Women s and Children s Health, Dunedin School of Medicine, Dunedin; Benj

Acknowledgements

- This study was funded by the University of Otago, Dunedin, New Zealand.-

Correspondence

Helen Paterson, Department of Women s and Children s Health, Dunedin School of Medicine, University of Otago, PO Box 913, Dunedin, New Zealand.

Correspondence Email

helen.paterson@otago.ac.nz

Competing Interests

XXX

'-- Institute of Medicine (IoM), National Research Council (NRC). Weight Gain During Pregnancy: Reexamining the Guidelines. Washington (DC), National Academies Press (US) 2009. Ministry of Health. Childhood Obesity Plan. Wellington, New Zealand:

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