Introduction: Low birthweight, which can be caused by inappropriate intrauterine growth or prematurity, is associated with development of gestational diabetes mellitus (GDM) as well as pre-eclampsia later in life, but the relative effects of prematurity and inappropriate intrauterine growth remain uncertain.
Methods: Through nation-wide registries we identified all Danish mothers in the years 1989-2007. Two separate cohorts consisting mothers born 1974-1977 (n = 84219) and 1978-1981 (n = 32376) were studied, due to different methods of registering birthweight and gestational age in the two periods. Data was linked with information on GDM, pre-eclampsia and education.
Results: In a multivariate logistic regression model the odds of developing GDM was increased by 5-7% for each week the mother was born before term (p = 0.018 for 1974-1977, p = 0.048 for 1978-1981), while the odds were increased by 13-17% for each standard deviation (SD) reduction in birthweight for gestational age for those who were small or normal for gestational age (p<0.0001 and p = 0.035) and increased by 118-122% for each SD increase above the normal range (p<0.0001 and p = 0.024). The odds of pre-eclampsia was increased by 3-5% for each week the mother was born before term (p = 0.064 and p = 0.04), while the odds were increased 11-12% for each SD reduction in birthweight for gestational age (p<0.0001 and p = 0.0002).
Conclusion: In this cohort of young Danish mothers, being born premature or with increasingly low birthweight for gestational age was associated with an increased risk of GDM and pre-eclampsia in adulthood, while increasingly high birthweight for gestational age was associated with an increased risk of GDM and a decreased risk of pre-eclampsia. Inappropriate weight for gestational age was a more important risk factor than prematurity.