Gestational weight loss has adverse effects on placental development

To clarify whether mothers with gestational weight loss (GWL) were likely to have adverse effects on the placenta.

Subjects who delivered viable singleton infants after 24 weeks of gestation were enrolled. A retrospective analysis to evaluate cases of GWL in association with the findings of the placenta and amniotic membrane after delivery was conducted. After consideration of confounders, a case-control study with matched pairs (1:2) was performed.

Of all subjects (5551 cases), 83 cases (1.5%) with GWL were found. Since the pre-pregnancy maternal body mass index (BMI) was significantly higher in cases, 166 controls with a matched BMI were selected. The neonatal birth weights, placental weights and the umbilical cord length in cases were significantly smaller than in controls (p < 0.05). Preterm delivery and small for gestational age (SGA) infants were more frequently observed in cases compared with controls [odds ratio (OR) 6.3; 95% confidence interval (CI) 3.3, 12.1, OR 4.3; 95% CI 1.9, 9.9]. pPROM were observed in 10.8% of the cases and 1.8% of the control (OR 6.6; 95% CI 1.7, 25.1). However, the frequencies of chorioamnionitis and the cervical length at second trimester were not different between the two groups.

GWL is associated with SGA, small placenta, short umbilical cord length, preterm delivery and pPROM.