Third Trimester Ultrasound Stratifies Risk of Peripartum Complications in Pregnancies Complicated by Impaired Glucose Tolerance

Abstract

Objective The objective of our study was to investigate the effect of impaired glucose metabolism (IGM) and ultrasound (US) findings consistent with hyperglycemia on maternal and neonatal outcomes. Study Design This was a retrospective case-control study of singleton, nonanomalous pregnancies with an elevated 1-hour glucose screening test (GST) completed after 23 weeks of gestation. IGM was defined as a 1-hour GST of >130, but less than two abnormal values on 3-hour glucose tolerance test (GTT). Gestational diabetes was defined as two or more abnormal values on 3-hour GTT. Ultrasound evidence of hyperglycemia was defined as abdominal circumference >95th centile and/or polyhydramnios. Individuals with IGM were divided into those with ultrasound evidence of hyperglycemia (impaired glucose metabolism consistent with ultrasound findings [IGM-US]) and those without IGM. Maternal demographics, delivery outcomes (gestational age at delivery, delivery mode, shoulder dystocia, lacerations), postpartum hemorrhage, and neonatal outcome (birth weight centile [BW%], neonatal intensive care unit admission, hypoglycemia, and glucose) were recorded. Composite morbidity was tabulated. Delivery and neonatal outcome variables were compared in individuals with IGM-US, IGM, and gestational diabetes mellitus (GDM). Odds ratios were calculated and adjusted for maternal age, BMI, and gestational weight gain. Results A total of 637 individuals with an abnormal 1-hour GST were included (122 with IGM-US, 280 with IGM, and 235 with GDM). When compared to the IGM group, IGM-US had higher rates of cesarean delivery and BW% > 90th centile at delivery (adjusted odds ratio [aOR]: 1.7 [1.1–2.8] and aOR: 5.9 [2.7–13.0], respectively). Individuals with GDM also demonstrated similar rates with BW% > 90% but not cesarean section(aOR: 3.9 [1.8–8.5] and aOR: 1.4 [0.9–2.1], respectively). The remaining maternal and fetal outcomes were similar. Conclusion Women with impaired glucose tolerance should have a third-trimester ultrasound to identify an increased risk of perinatal complications. Key Points