Prepregnancy dieting and obstetrical and neonatal outcomes: Findings from a national surveillance project in the United States.

PROBLEM AND BACKGROUND: Women with overweight or obesity are recommended to lose weight before pregnancy. Dieting is one of the most used weight control strategies. However, the health implications of dieting before pregnancy remain unclear.

AIM: To evaluate the associations of dieting during the year before pregnancy with obstetrical and neonatal outcomes, including gestational weight gain (GWG), gestational diabetes, low birthweight, macrosomia, small-for-gestational-age infants (SGA), large-for-gestational-age infants (LGA), and preterm birth.

METHODS: This study analyzed data from the Pregnancy Risk Assessment Monitoring System (PRAMS), which is a surveillance project in the United States that collects data on maternal health before, during, and after pregnancy. Women who participated in PRAMS phase 7 with a prepregnancy body mass index ≥25 kg/m2 and a singleton birth were eligible. Statistical analyses included logistic regressions and post-hoc mediation analysis (Sobel Test).

FINDINGS: A total number of 51,399 women were included in the analysis. Women who self-reported prepregnancy dieting (42.8 %) had lower odds of SGA (adjusted odds ratio [aOR]: 0.87; 95 % CI: 0.79-0.97), and higher odds of excessive GWG vs adequate GWG (aOR: 1.42; 95 % CI: 1.32-1.52), gestational diabetes (aOR: 1.12; 95 % CI: 1.02-1.22), and LGA (aOR: 1.18; 95 % CI: 1.08-1.28). Furthermore, the association between prepregnancy dieting and LGA was mediated by excessive GWG (Sobel Test z-value = 5.72, p < 0.01).

DISCUSSION AND CONCLUSION: This analysis revealed that prepregnancy dieting was associated with several adverse consequences, including excessive GWG, gestational diabetes, and LGA infants. Findings contribute to an improved understanding of the perinatal implications of prepregnancy dieting.