Fetal Abdominal Circumference and Risk of Neonatal Morbidity in Pregnancies Complicated by Diabetes [A246]

INTRODUCTION: We aimed to characterize the relationship between fetal abdominal circumference and neonatal morbidity in pregnancies complicated by diabetes. METHODS: After institutional review board approval, patients with gestational diabetes (GDM) or preexisting diabetes type 1 or type 2 (T1DM, T2DM) who delivered a live, singleton, non-anomalous infant at a single center 2002–2013 were identified within a large, National Institutes of Health-funded database of detailed pregnancy and delivery information extracted by trained research nurses. Neonatal morbidity (NM) was defined as one or more of the following: 5-minute Apgar <7, arterial cord pH <7.0, sepsis, neonatal death, or need for respiratory support, chest compressions, phototherapy, exchange transfusion, or hypoglycemia treatment. Rates of morbidity were calculated for the following groups stratified by fetal abdominal circumference (AC) percentile for gestational age: below the 20th percentile, 20th–39th percentile, 40th–59th percentile, 60th–79th percentile, and 80th percentile or greater. Unadjusted relative risk (RR) of neonatal morbidity was calculated for each group, with AC 40th–59th percentile as the reference. RESULTS: A total of 721 eligible pregnancies were identified (643 GDM, 35 T1DM, 43 T2DM). Neonatal morbidity occurred in 261 (36%). The lowest rate of neonatal morbidity (22%) occurred in pregnancies with a fetal AC below the 20th percentile (RR, 0.55; 95% CI, 0.31–0.98). The highest rate of neonatal morbidity (42%) occurred in those with an AC at or above the 80th percentile, but this was not a statistically significant increase in risk compared to the reference group (RR, 1.05; 95% CI, 0.82–1.33). CONCLUSION: Among pregnancies complicated by diabetes, fetal abdominal circumference below the 20th percentile was associated with decreased risk of neonatal morbidity.