The aim of this study was to investigate the effects of hypoglycemia measured using 2-h 75-g oral glucose tolerance test (OGTT) on neonatal biometrics (birth weight, head circumference and body length of newborns) and perinatal outcomes.

According to the definition of hypoglycemia by the American Diabetes Association, women with blood glucose levels of ≤70 mg/dL after fasting or at 1 or 2 h after eating measured using on 2-h 75-g OGTT were grouped into a hypoglycemia group. In accordance with the criteria of World Health Organization and the International Association of Diabetes and Pregnancy Study Groups, as per the 2-h 75-g OGTT performed in the second trimester, women with gestational diabetes and were excluded from the study. Also, women meeting the following criteria were excluded from the study: missing records, aged <19 or ≥35 years, multiple pregnancies, delivery before the 24^th gestational week, and ≤500-g newborn. Other exclusion criteria included pregnant women with known type 1 and type 2 diabetes mellitus, gestational or essential hypertension, cigarette and/or alcohol abuse, thyroid disease, BMI of <19 and >30, placental abnormalities with variation and/or dysfunction, intrauterine growth restriction, and abnormalities of the umbilical cord.

A total of 625 pregnant women who met the inclusion criteria were included in the study. Hypoglycemia was found in 71 pregnant women according to 2-h 75-g OGTT. The remaining 554 women were grouped into the normoglycemia group. The birth weight, head circumference, and body length of newborns were significantly lower in the hypoglycemia group (p < 0.001, p = 0.004, and p = 0.006, respectively). There was no significant difference between both groups in terms of body mass index, parity, fetal sex, delivery type, and Apgar scores.

Glycemia with blood glucose levels of ≤70 mg/dL measured using 75-g OGTT during pregnancy is associated with lower birth weight, small head circumference, and short body length in newborns compared to the normoglycemic group. Hence, pregnant women who are diagnosed with blood glucose levels of ≤70 mg/dL using 2-h 75-g OGTT should be carefully managed.