Pre-pregnancy weight change and incidence of gestational diabetes mellitus: A finding from a prospective cohort study
Introduction
Gestational diabetes mellitus (GDM), a state of impaired glucose tolerance recognised for the first time in pregnancy, is one of the most frequent pregnancy complications associated with higher maternal and perinatal adverse outcomes [1]. The prevalence is increasing mainly as a result of the rising proportion of women with pre-pregnancy obesity, sedentary lifestyles and advanced maternal age at birth [2], [3]. Women with GDM are more likely to develop type 2 diabetes in later life compared to women without GDM [4].
The cross sectional association between body mass index (BMI) and GDM is well established [5]. Although evidence of a causal relationship is scarce, in a meta-analysis of observational studies, the risk of development of GDM ranged from a two- to fivefold increase for women who were overweight and severely obese prior to pregnancy, respectively [6]. A number of studies [7], [8], [9], [10] have also showed that weight gain over the life course has substantial effect on the development of diabetes and other cardiovascular risks in non-pregnant women and men. However, there are only a few studies [11], [12] of the relationship between early adult pre-pregnancy weight change and the risk of GDM.
In the life course, young adults (20–29 years of age) are at higher risk of increased weight gain [13]. Changes in the early adult pre-pregnancy weight over the reproductive years of the life course may have more important effect than the immediate pre-pregnancy weight. The women who develop GDM have been shown to have had nearly a twofold rate of weight gain prior to pregnancy than non GDM women [11]. Even in a normal range of BMI, a pre-pregnancy weight gain has been associated with an elevated risk of GDM [12], [14]. Weight gain/retention between consecutive pregnancies has also been found to be linked with the increased risk of GDM [14], [15]. However, the existing scarce studies were limited to nursing professional mothers whose childhood body shape and weight (at 18 years) were reported retrospectively and subsequent adult weights were collected over a short interval [12]. The other studies collected weight trajectories in a single retrospective interview [11] or measured only inter-pregnancy weight change [14], [15] rather than over the reproductive course of life. These studies were further limited to clinical populations and lacked adjustment for potential confounders such as diet, and physical activity, a fact acknowledged by the authors [11].
We therefore primarily aimed to examine whether the changes in early adult pre-pregnancy weight from baseline (1996, 18–23 years of age) to 25–30 years of age (2003) and to each study pregnancy (with children born between 2003 and 2012) are associated with the development of GDM using data from a broadly representative population-based cohort study of Australian women. As a secondary objective, we investigated the effect of early adult pre-pregnancy weight change on the subsequent risk of GDM in women within different BMI categories.
Section snippets
Data source and participants
The Australian Longitudinal Study on Women’s Health (ALSWH) is an ongoing large longitudinal population-based study examining the health of over 58,000 Australian women. In 1996, three cohorts of women born in 1973–78 (‘young’, aged 18–23 at baseline), 1946–51 (‘mid-age’, aged 45–50 at baseline), and 1921–26 (‘older’, aged 70–75 at baseline) were randomly selected from the national Medicare health insurance database, which includes all Australian citizens and permanent residents. Random samples
Results
A total of 3111 women who reported 5242 pregnancies between S3 and S6 (mean 1.7 pregnancies per women) were included. Of these pregnancies, 229 new cases of GDM (4.4%) were reported. The mean age of women at the baseline was 20 (SD 1.5) years. About three fifths (58.8%) of women were urban residents. The majority of women had completed up to year 12 (66.6%), were never married (82.9%), and were nulliparous (97.4%). Among the study population, 9.3%, 14.6% and 4.4% of women were underweight,
Discussion
We found baseline (mean age 20 years) and pre-pregnancy obesity (on average approximately a year before a pregnancy) to be significantly associated with increased GDM risk, after adjustment for potential confounders. The association was stronger with the latter as pre-pregnancy obesity is the closest measure to the event of pregnancy. While others have shown inconsistencies between early adult obesity and latter GDM risk [11], there is a general consensus in the relationships of pre-pregnancy
Author contributions
A.A.A designed the study, performed the analysis, and drafted the manuscript; L.R.T and G.D.M contributed to the design of the study, analyses, interpretation of the results, and critical revision of the manuscript for important intellectual content. All authors have approved the final version.
Conflict of interest
The authors declare that they have no conflict of interests to disclose.
Acknowledgements
The research on which this paper is based was conducted as part of the ALSWH by the University of Queensland and the University of Newcastle. We are grateful to the Australian Government Department of Health for funding and to the women who provided the survey data. A.A.A is supported by an International Postgraduate Research Scholarship and a UQ Centennial scholarship. G.D.M is funded by an Australian Research Council Future Fellowship (FT120100812). The founder has no role in study design
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2021, Diabetes Research and Clinical PracticeCitation Excerpt :Thus, far too many girls may be at an increased risk of developing GDM. Although studies examining adult pre- and inter-pregnancy weight change suggest that weight loss may mitigate the risk of GDM [14,22–24], the impact of changing BMI status from child to adult ages on the risk of developing GDM is unknown. Therefore, in a large cohort of Danish nulliparous women, we examined whether a woman’s own birthweight, childhood height, and BMI as well as changes in BMI from childhood to adulthood were associated with risks of GDM in the first pregnancy.
Deleterious effects of gestational diabetes mellitus on the characteristics of the rectus abdominis muscle associated with pregnancy-specific urinary incontinence
2020, Diabetes Research and Clinical PracticeCitation Excerpt :The are some risk factors for PSUI that could be confounding factors, such as maternal age, multiparity [47], hormonal status [42] and pre-pregnancy overweight [48]. Further, increased maternal age [49], multiparity [50], and pre-pregnancy BMI [51] are well-established clinical risk factors for GDM. However, the risk factors associated with GDM and PSUI that could influence our results did not show any statistical differences in their clinical characteristics (i.e., age, parity, pre-pregnancy BMI, previous c-section, previous newborn weight, and weight gain during pregnancy) between the groups, which allowed the effects of the confounding variables to be avoided, suggesting that the changes observed in the RAM were directly related to the effects of GDM and PSUI alone.