In New Zealand, as in most low-fertility countries, there has been an increase in the number of pregnant women with chronic health conditions.1,2 This is at least partly due to the rising age at childbearing.3 These conditions increase the risk of adverse events and outcomes during and after pregnancy, including stillbirth, preterm birth, Caesarean delivery, low birth weight or macrosomia, hypertensive and cardiac complications, and postnatal depression.4–7 To address these risks, there is an increasing emphasis on preconception or interconception care for women with chronic health conditions.8,9 These forms of preconception care are predicated on the pregnancy being planned.

Planning pregnancy is often considered to be a necessity for increasing public health. However, this ‘pregnancy planning paradigm’ is problematic as it does not reflect the thoughts, feelings or behaviours of many, perhaps most, women (Aiken et al 2016). In New Zealand, a majority of pregnancies are reported as unplanned,10 suggesting that this is a normal part of life for most women. Although planning may not be necessary for most women, there are some women for whom planning may be beneficial. Planning allows for preconception care, with unplanned pregnancies receiving less preconception and antenatal care.11 For women with chronic conditions, preconception care may be able to decrease their potential elevated risks. Therefore, it will be useful to identify the extent of planning among women who may benefit from it.

The extent of pregnancy planning among women with a chronic health condition in New Zealand is currently unknown. In Europe and the US, women with chronic conditions do not appear to be planning their pregnancies any differently from women without chronic conditions. Women with diabetes, heart disease and hypertension have the same number of unintended pregnancies as women without these conditions.12 Depression has also been found to be associated with unplanned pregnancies.13 Most young women with diabetes are not practicing the full extent of recommended pregnancy planning, including reproductive health consultation and use of effective contraception if not intending pregnancy.14 Women with diabetes and hypertension may not be aware of the risks of pregnancy for women with their condition, and do not consider preconception care a priority.15 Like other women, women with chronic conditions may not have been using contraception because they believed that they would not become pregnant, did not consider using contraception, or were dissatisfied with their method of contraception.16 Moreover, their chronic condition could have made it difficult to find an effective contraceptive option.17 Because pregnancy planning is complex and most studies do not consider the range of women’s experiences, there may be further variations among women.18

Ethnicity provides an important context for understanding the place of pregnancy and childbearing in family life. Planning that focuses on behaviour and medical intervention may hold a different meaning among Pākehā (European New Zealand) women than among Māori and Pacific Island women.19,20 This diversity in experiences of family life should be celebrated. Less positive, however, is that Māori and Pacific Island women face economic and health disadvantages.2,10 The interdependent links between economic disadvantage, chronic health conditions and unplanned pregnancies suggest a potential for exacerbation of health risks.

This is the first New Zealand study to observe unplanned pregnancies among women with chronic health conditions, including diabetes, heart disease, asthma, depression and anxiety. It leverages the unique capabilities of the Growing Up in New Zealand study to identify whether unplanned pregnancies occur among women with chronic health conditions, particularly if there is a co-occurrence of socioeconomic disadvantage, asking:

1. What proportion of pregnancies among women with a chronic health condition is reported as unplanned?
2. For pregnant women with chronic health conditions, which demographic and socioeconomic characteristics co-occur with reporting their pregnancy as unplanned?

Method

Data are from the antenatal wave of the Growing Up in New Zealand (GUiNZ) cohort study, a nationally-representative sample of pregnant women due to give birth in 2008/2009.21 analysis uses the first interview, conducted during the last half of pregnancy. Chronic health conditions are identified by responses to a question asking the woman if she had an illness diagnosed by a doctor; these are coded as chronic if the respondent replied ‘before this pregnancy and during this pregnancy’. Illnesses include diabetes, heart disease or high blood pressure, asthma, depression and anxiety or panic attacks. Planning is identified by responses to the question: “Did you plan this pregnancy or was it a surprise?”

Question 1 is answered using chi-square tests comparing the proportion of women reporting planned and unplanned pregnancies for the total sample, within each chronic health condition, and for multimorbidity.

Question 2 focuses on women with chronic conditions, and uses chi-square tests to compare the proportion of women reporting planned and unplanned pregnancies by sociodemographic characteristics. Correlation analyses (not shown) confirm that all characteristics are highly correlated with one another. The analysis of individual characteristics must thus be mindful that each of these characteristics is closely tied with all others.

Results

Over 15% of the sample had at least one chronic health condition, as shown in the first column of Table 1. The most frequently occurring condition was asthma, reported by over 7% of the women, and the least frequent was diabetes, reported by less than 1% of the women. Just over 2% of all women reported multimorbidity (more than one condition), and of these 162 women, 81% were diagnosed with depression, 64% with anxiety, 43% with asthma, 21% with heart disease and 11% with diabetes. The presence of these conditions among pregnant women differed by ethnicity, with significant differences observed for all conditions except heart disease. For asthma, depression and multimorbidity, there were similar proportions of Māori and Pākehā women with the conditions, but a lower proportion among Pacific Island women and the lowest proportion for Asian women. Compared to Pākehā, all other groups showed elevated rates of diabetes and lower rates of diagnosed anxiety.

Table 1: Chronic health conditions and pregnancies reported as unplanned.

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Note: 6,822 pregnant women in the total sample of the first wave of GUiNZ. Chi-square tests examined the difference between planned and unplanned pregnancies for each condition.
1Women with more than one condition are included within each condition they report.
‡p<.1 *p<.05 **p<.01 ***p<.001.

Among all women, 39.6% reported their pregnancies as unplanned. Compared to this overall proportion, a higher percentage (from 43% to nearly half) of women with chronic health conditions reported their pregnancies as unplanned (second column of Table 1). Pregnant women who had been diagnosed with depression or asthma reported a significantly higher proportion of unplanned pregnancies than women without these conditions. Women with diabetes also had an elevated proportion with unplanned pregnancies, but due to the small number of women with this condition in the sample, the difference approached but did not reach conventional levels of significance. When the 15% of women with any of the conditions are considered as a group, they report 44.4% of their pregnancies as unplanned. With this large group of women with a higher proportion of unplanned pregnancies considered separately, women without any of the conditions show a smaller proportion with unplanned pregnancies (38.7%).

Characteristics associated with unplanned pregnancies for women with chronic conditions are shown in Table 2. Unplanned pregnancies were reported by women across all characteristics. Even at their lowest proportions, unplanned pregnancies represented one-fifth to one-third of substantial groups of women (ie, women with tertiary education, women aged 30–39). The highest proportions of unplanned pregnancies were reported by nearly 80% of women with incomes less than $30,000, three-quarters of young women, nearly three-quarters of women with no coresident partner, two-thirds of women identifying as Māori or Pacific Islander, and over half of women with less than a tertiary degree. Parity and migrant status were not associated with unplanned pregnancy.

Table 2: Socioeconomic characteristics of women with chronic conditions and pregnancies reported as unplanned.

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Note: Data are from the first wave of GUiNZ, and include 1,030 pregnant women reporting a chronic health condition (asthma, heart disease, diabetes, depression and/or anxiety). Chi-square tests examined the difference between planned and unplanned pregnancies for each characteristic.
***p<.001.

As the characteristics are interrelated, these findings can best be understood by viewing them as a whole and recognising that unplanned pregnancies are a widespread experience across all characteristics, but are reported most frequently by women experiencing socioeconomic disadvantage.

Discussion

Unplanned pregnancies are reported by about half of all pregnant women with chronic health conditions in New Zealand. This was a higher proportion than among women without health conditions: Women with any chronic health conditions reported 45% of their pregnancies as unplanned, compared to 39% of women without health conditions. The proportion of unplanned pregnancies was particularly high among women with diagnosed depression (49%) and asthma (44%). Among women who identified as Māori or Pacific Islander and who had a chronic health condition, about two-thirds of pregnancies were reported as unplanned. For women with chronic conditions, the proportion of unplanned pregnancies was considerably higher among women whose characteristics indicate socioeconomic disadvantage. In particular, among pregnant women with chronic health conditions who were low-income, young, did not have a coresident partner and had less education, from half to nearly 80% of pregnancies were reported as unplanned.

Given the prevalence of each condition in the sample, the year 2008 in New Zealand would have seen an estimated 2,200 unplanned pregnancies of women with asthma, over 1,300 of women with depression, nearly 700 of women with anxiety, nearly 500 of women with heart disease/hypertension and nearly 400 of women with diabetes. This is a substantial number of women with unplanned pregnancies and chronic conditions who are at an elevated risk of not receiving preconception and antenatal care, and thus a higher chance of experiencing adverse events in their pregnancies.9,11 This risk can be mitigated by health practitioners, particularly midwives and obstetricians who are prepared to provide care to women with chronic health conditions whose pregnancies are a surprise.

The strength of this study is its population-based sample, which allows for the comparison of pregnant women with and without a range of chronic health conditions. The accompanying weakness is that the conditions are broadly grouped, obscuring the exact diagnosis. These are self-reported diagnoses, leaving open the possibility that the analysis missed women with diagnosed conditions who did not report them, as well as women with undiagnosed conditions. The results should therefore be interpreted as a conservative estimate. There are also only a very small number of women with diabetes in the sample. Given the suggestion of disproportionate numbers of unplanned pregnancies along with the serious consequences of a lack of preconception care for women with diabetes, further research focusing on women with Type I and Type II diabetes is warranted.

An additional limitation of this study is that it only includes women who are already pregnant. This means that it is not possible to identify the rate of pregnancy among women with chronic conditions. That calculation requires population-level data, and will be the target of future research. The dichotomous measure of planning used in this survey does not reflect the full range of women’s experiences.17 A more comprehensive approach to measuring pregnancy planning and perspectives is necessary, and should be considered for future surveys. Future studies could also examine the prospective childbearing intentions and contraceptive use of women with chronic health conditions, to illuminate the extent to which pregnancies are being planned and prevented.

Both chronic illness and unplanned pregnancy are more prevalent and pose greater risks in the presence of socioeconomic disadvantage. Together, they create a high-risk situation that is rarely considered. Current guidelines focus on preconception care, which advises and/or assumes planning pregnancies, as a key part of managing pregnancy with chronic conditions. Women with a chronic health condition are already engaged with the healthcare system, offering an enhanced opportunity for professionals to support them across their reproductive lifecourse. Health professionals caring for women with chronic conditions should ask all women about their childbearing intentions and provide them with a range of contraceptive options and preconception care.

Assistance with individual planning offers one option, but a more effective strategy takes a broader approach by improving the health of the entire population.8,22 This will only be possible if New Zealand’s stark health inequities, in particular those faced by Māori and Pacific Islanders, are addressed. The high rate of unplanned pregnancies among women with chronic health conditions adds urgency to the necessity of addressing the pregnancy and reproductive health of all women by improving access to healthcare and by ensuring a healthy environment for everyone.

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