Hypoglycemia in pregnancy: maternal characteristics and neonatal outcomes from oral glucose tolerance tests

Heterogenous results were reported in the effects of hypoglycemia in pregnancy. This study evaluated pregnancy outcomes in women with hypoglycemia during the antenatal 75-gram oral glucose tolerance test (OGTT).

OGTT results of the mothers of all live-born delivered in a tertiary obstetrics centre were evaluated between Jan 2021 and June 2022. All patients had OGTT at 26-30th weeks of gestation. Hypoglycemia was defined as any low plasma glucose ≤ 3.5mmol/L on OGTT. Maternal and neonatal outcomes were compared among the four groups; normal results (group 1), hypoglycemia in OGTT (group 2), gestational diabetes mellitus (GDM) (group 3) and pregestational diabetes mellitus (DM) (group 4).

There were 3715 women delivered within the study period and 3164 (85.2%) had normal results. 65 (1.7%) women had hypoglycemia, 464 (12.5%) women had GDM and 22 (0.6%) women had pregestational DM. None of the Group 2 patients were symptomatic. Maternal demographics were comparable. Patients with hypoglycemia during OGTT were not at an increased risk of preterm delivery (1.5% vs. 2.8%, p = 0.86). There was no statistical difference in the incidence of Caesarean Sect. (32.3% vs. 34.4%, p = 0.54), postpartum haemorrhage (10.8% vs. 14.7% p = 0.28). Women with hypoglycemia during OGTT were not at risk of adverse outcome in terms of neonatal intensive care unit admission (16.9% vs. 8.5%, p = 0.28) and Apgar score at 5th minute of life (9.8 vs. 9.8, p = 0.17).

Hypoglycemia in antenatal OGTT is not associated with adverse neonatal or maternal outcomes. It is likely to resolve after delivery.