Abstract
Background. Associations between preterm delivery (PTD) and pre-pregnancy body mass index (BMI) and pregnancy weight gain may differ across outcome subtypes. Methods. The authors analyzed data from 2,468 cohort participants in western Washington State, USA (1996–2005) and examined pre-pregnancy BMI and weight gain rate from pre-pregnancy to 18–22 weeks’ gestation in relation to spontaneous PTD after preterm labor, spontaneous PTD after preterm premature rupture of membranes (PPROM), and indicated PTD. Results. Each 5kg/m2 BMI increase was associated with indicated PTD (adjusted odds ratio [OR] 1.71, 95% confidence interval [CI] 1.40–2.06). The association weakened somewhat after adjustment for hypertension and diabetes before and/or during pregnancy (5kg/m2 adjusted OR, 1.40; 95% CI, 1.12–1.75). Associations with spontaneous PTD and PPROM were weaker (5kg/m2 adjusted ORs, 0.90 and 1.14, respectively). Weight gain was associated with indicated delivery among women with normal BMI (0.1kg/week adjusted OR, 1.22; 95% CI, 1.02–1.45) but not among overweight or obese women (adjusted OR, 1.02; 95% CI, 0.87–1.20). Weight gain was inversely associated with spontaneous PTD (0.1kg/week adjusted OR, 0.87; 95% CI, 0.77–0.99) and not strongly associated with PPROM (adjusted OR, 1.03; 95% CI, 0.90–1.17). Conclusions. Pre-pregnancy overweight increases indicated PTD risk independently of hypertension and diabetes. High early pregnancy weight gain increases indicated PTD risk in women with a normal BMI.
| Abbreviations | ||
| BMI | = | body mass index |
| CI | = | confidence interval |
| OR | = | odds ratio |
| PPROM | = | preterm premature rupture of membranes |
| Abbreviations | ||
| BMI | = | body mass index |
| CI | = | confidence interval |
| OR | = | odds ratio |
| PPROM | = | preterm premature rupture of membranes |