Impact of gestational diabetes mellitus on neonatal outcomes in small for gestational age infants: a multicenter retrospective study

Objective: To evaluate obstetric and perinatal outcomes among small for gestational age (SGA) infants born to patients diagnosed with Gestational diabetes mellitus (GDM). Materials and methods: A multicenter retrospective cohort study between 2005 and 2021. The perinatal outcomes of SGA infants born to patients with singleton pregnancy and GDM were compared to SGA infants born to patients without GDM. The primary outcome was a composite adverse neonatal outcome. Infants with known structural/genetic abnormalities or infections were excluded. A univariate analysis was conducted followed by a multivariate analysis (adjusted odds ratio [95% confidence interval]). Results: During the study period, 11,662 patients with SGA infants met the inclusion and exclusion criteria. Of these, 417 (3.6%) SGA infants were born to patients with GDM, while 11,245 (96.4%) were born to patients without GDM. Overall, the composite adverse neonatal outcome was worse in the GDM group (53.7% vs 17.4%, p < 0.01). Specifically, adverse neonatal outcomes such as a 5 min Apgar score < 7, meconium aspiration, seizures, and hypoglycemia were independently associated with GDM among SGA infants. In addition, patients with GDM and SGA infants had higher rates of overall and spontaneous preterm birth, unplanned cesarean, and postpartum hemorrhage. In a multivariate logistic regression assessing the association between GDM and neonatal outcomes, GDM was found to be independently associated with the composite adverse neonatal outcome (aOR 4.26 [3.43–5.3]), 5 min Apgar score < 7 (aOR 2 [1.16–3.47]), meconium aspiration (aOR 4.62 [1.76–12.13]), seizures (aOR 2.85 [1.51–5.37]) and hypoglycemia (aOR 16.16 [12.79–20.41]). Conclusions: Our study demonstrates that GDM is an independent risk factor for adverse neonatal outcomes among SGA infants. This finding underscores the imperative for tailored monitoring and management strategies in those pregnancies.