Impact of Gestational Diabetes on Neonatal Birth Weight and Maternal Postpartum Metabolic Changes.

BACKGROUND

Gestational diabetes mellitus (GDM) is a growing public health concern globally, particularly in the context of rising maternal obesity and glucose intolerance. GDM poses significant risks to both neonatal and maternal health, including fetal overgrowth, birth complications, and long-term metabolic disorders. This study aimed to evaluate the impact of GDM on neonatal birth weight and maternal postpartum metabolic changes. The primary objective was to assess the incidence of macrosomia and small-for-gestational-age (SGA) births in pregnancies complicated by GDM. Secondary objectives included evaluating postpartum glycemic and lipid profiles, comparing metabolic parameters at six weeks and six months between GDM and non-GDM groups, and identifying predictive and moderating variables such as glycemic control, pre-pregnancy BMI, and gestational weight gain.

METHODOLOGY

A prospective cohort study was conducted over an 18-month period (October 2023 to April 2025) at Health Net Hospital, a tertiary care and referral center located in Peshawar, Pakistan. A total of 219 pregnant women were initially screened for eligibility. Following the application of inclusion and exclusion criteria, 189 women were enrolled, 94 diagnosed with GDM and 95 without GDM, serving as matched controls. Data were collected at three time points: during the second trimester (baseline), at delivery, and during postpartum follow-up at six weeks and six months. Maternal metabolic markers, including glycemic and lipid profiles, were assessed longitudinally, while neonatal outcomes such as birth weight, NICU admission, and hypoglycemia were documented at birth. Follow-up adherence was ensured through scheduled reminders and flexible appointment rescheduling. Clinical and laboratory data were collected using standardized protocols by trained staff. Logistic regression analysis was used to identify independent predictors of adverse maternal and neonatal outcomes, with adjustments for potential confounders. Data analysis was performed using IBM SPSS Statistics for Windows, Version 29.0.2.0 (IBM Corp., Armonk, New York, United States).

RESULTS

Neonates of GDM mothers had significantly higher birth weights (mean 3689 g vs. 3143 g; p<0.0001), with increased incidence of neonatal hypoglycemia in 16 (17%) GDM cases compared to four (4.2%) non-GDM cases and NICU admissions in 19 (20.2%) GDM neonates versus five (5.3%) non-GDM neonates. GDM mothers exhibited elevated fasting glucose at six weeks (mean 98.5 mg/dL) and six months (94.1 mg/dL) postpartum, compared to non-GDM mothers (85.3 mg/dL and 83.2 mg/dL, respectively; p<0.0001). Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and triglyceride levels were also significantly higher in the GDM group. GDM (OR=2.8), higher pre-pregnancy BMI, and poor glycemic control (HbA1c >5.9%) were independent predictors of neonatal macrosomia and maternal insulin resistance.

CONCLUSION

GDM significantly increases the risk of macrosomia, neonatal complications, and sustained maternal metabolic dysfunction postpartum. These findings underscore the importance of early diagnosis, effective glycemic control, and structured postpartum follow-up to mitigate long-term risks.