The risk of small and large for gestational age newborns in women with gestational diabetes according to pre-gestational body mass index and weight gain.

Aim: To explore the effects of pregestational body mass index (BMI) and gestational weight gain (GWG) on maternal and neonatal outcomes of women with gestational diabetes mellitus (GDM).

Methods: We conducted retrospective cohort analyses of outcomes among women with GDM who delivered at Shamir Medical Center, Israel (2017-2018).

Results: We included 673 women with GDM in our analysis, 217 (32.24%) with appropriate GWG (aGWG), 247 (36.7%) with excessive GWG (eGWG), and 209 (31%) with insufficient GWG (iGWG). Cesarean section (CS) was less prevalent among women with iGWG (19.6%), compared with women with eGWG (31.2%) and aGWG (31.1%) (p = .008). Small for gestational weight (SGA) newborns were more prevalent in women with iGWG 9.1%, compared with 2% and 0.9% for women with eGWG and aGWG, respectively (p<.001). Large for gestational age (LGA) newborns were significantly more prevalent in women with eGWG 17.4% compared with 4.8% and 9.7% in patients with iGWG and aGWG women, respectively (p<.001). SGA and LGA newborns were more prevalent in women with iGWG and e-GWG across all pre-gestational BMI groups >18.5 kg/m².

Conclusions: A complex interplay exists between pregestational weight, GWG, and GDM and pregnancy outcomes, specifically SGA and LGA newborns. A strict follow-up considering the pregestational BMI, GWG, blood glucose levels, treatment modality, and fetal abdominal circumference could assist in managing the complex interplay of patients with GDM for better neonatal outcomes.