(477) Asymmetrical vs. Symmetrical Large for Gestational Age Infants in Pregestational Diabetics: Differences in Neonatal Morbidity

Objective: Research has highlighted the importance of distinguishing between asymmetrical large for gestational age (aLGA) and symmetrical large for gestational age (sLGA) infants, with the former being associated with higher risk of neonatal complications. We hypothesized that the prevalence and complications of aLGA is higher in infants born to mothers with type 1 diabetes (T1D) compared to type 2 diabetes (T2D).

Study Design: Women with insulin-treated pregestational diabetes (PGDM) were recruited and managed prospectively. Singleton pregnancies recruited before 14 weeks were included in this analysis. Patients were seen every 1-2 weeks and glycemic control was strictly managed using standardized protocols. Infants were weighed and measured immediately after birth and monitored for hyperbilirubinemia, hypoglycemia, and acidosis. LGA (birthweight > 90^th%ile) was categorized as aLGA if ponderal index (PI = weight/length³) was > 90^th%ile for gestational age, and sLGA if the PI was ≤ 90^th%ile. Outcomes were compared between infants with sLGA and aLGA and between infants born to mothers with T1D and T2D. Characteristics are reported as n (%), mean +/- standard deviation, or median and 25^th and 75^th percentiles. Statistical analyses included t-test, Wilcoxon rank sum, chi-square and logistic regression, as appropriate.

Results: The study included 132 LGA infants born to 321 women with T1D (41%) and 26 LGA infants born to 55 women with T2D (47%). The incidences of aLGA and sLGA in both groups and patient characteristics are presented in Table 1. In T2D, aLGA was associated with higher 2^nd and 3^rd trimester HbA1 compared to sLGA. There was a trend for a similar association in T1D. Most infant outcomes did not differ between groups nor did overall composite outcomes (Table 2).

Conclusion: There is a high rate of LGA, and particularly aLGA, among infants of mothers with both T1D and T2D. However, we identified few differences in infant outcomes between the groups, suggesting the need for further study into the clinical significance of aLGA as compared to sLGA.