Effect of pre-pregnancy BMI on gestational diseases and pregnancy outcomes

ObjectiveTo explore the effect of body mass index before pregnancy on various gestational diseases and adverse pregnancy outcomes.

MethodsRelated cohort studies at home and abroad from 2014 to 2019 in China, the United States, Canada, Vietnam and Indonesia were reviewed to evaluate the effects of pre-pregnancy BMI on the risk of gestational disease and pregnancy outcomes.The number of 773 articles was collected and 8 cohort studies were selected in accordance with the inclusion criteria for this study.

ResultsLow pre-pregnancy BMI could significantly increase the risk of postpartum hemorrhage (OR=7.1, 95%CI:2.7-13.6), acute renal failure (OR=1.6, 95%CI:0.1-5.3), low birth weight (OR=3.1, 95%CI:1.5-6.2), less than gestational age (OR=2.9, 95%CI: 1.9-4.5) and so on.High pre-pregnancy BMI could significantly increase the risk of preeclampsia (OR=1.09, 95%CI:1.04- 1.14), gestational hypertension (OR=5.49-11.42), cesarean section (OR=1.94, 95%CI:1.80-2.08), obstetric complications (OR=4.4-8.2), fetal macrosomia (OR=2.36, 95%CI:2.15-2.59) and other diseases.Spontaneous abortion, ectopic pregnancy were significantly associated with abnormal pre-pregnancy BMI (too high or too low).

ConclusionPre-pregnancy BMI is significantly associated with severe maternal diseases such as gestational hypertension, preeclampsia, gestational diabetes and adverse pregnancy outcomes like premature birth, abnormal birth weight, cesarean section.It suggests that more population-based prospective cohort studies are needed in this field to provide stronger evidence for pre-pregnancy weight management.