Hypoglycaemia During Oral Glucose Tolerance Test in Pregnancy and Feto-Maternal Outcomes: A Systematic Review and Meta-Analysis.

The significance of hypoglycaemia during oral glucose tolerance tests (OGTT) in pregnancy is uncertain. This systematic review and meta-analysis (SRM) evaluated if hypoglycaemia during OGTT predicts feto-maternal outcomes. Electronic databases were searched for studies in pregnancy where an OGTT at 24-28 weeks was done and feto-maternal outcomes were documented. Hypoglycaemia during OGTT (reactive hypoglycaemia) was defined as blood glucose < 90 mg/dl or less than the fasting-glucose value. Primary outcomes were the occurrence of small-for-gestational-age (SGA) and neonatal intensive-care unit (NICU) admission. Secondary outcomes were birthweight, macrosomia, large-for-gestational-age (LGA), gestational age at delivery (GA), 5-minute Apgar score (5AS), caesarean section (CS), and pregnancy-induced hypertension (PIH). Association of hypoglycaemia with pre-pregnancy maternal weight, maternal weight gain during pregnancy, and maternal age was noted. PRISMA guidelines were followed, and the preestablished protocol was registered on PROSPERO (CRD42025644556). From initially screened 448 articles, data from 13 articles involving 30,462 women were analysed. Compared to normoglycemia, hypoglycaemia during OGTT was associated with significantly higher SGA [OR1.81;95%CI1.31-2.50; = .0003], higher NICU admission [OR 1.44; 95% CI 1.17-1.76; < .001; I = 0%], lower birthweight [MD-68.38g; 95%CI -126.25- -10.52; = .020], lower macrosomia [OR 0.60;95%CI 0.42-0.86; < .005], higher 5AS <8 [OR2.53;95%CI1.37-4.68; = .003], lower CS [OR 0.82;95%CI0.75-0.90; < .0001], lower maternal pre-pregnancy weight [MD -4.90 kg; 95%CI 9.17-0.62; = .02; = 75%] and higher gestational-hypertension [OR 1.31; 95%CI 1.03 -1.66; = .030]. The rates of SGA, LGA, 5AS <8, and maternal age were similar in women with hypoglycaemia and gestational diabetes. Hypoglycaemia during OGTT is associated with gestational hypertension, lower birthweight, increased SGA, higher NICU admission, and higher 5AS <8. Lower maternal pre-pregnancy weight was a predictor of hypoglycaemia during OGTT.