Glycosylated hemoglobin level in the second trimester predicts birth weight and amniotic fluid volume in non-diabetic pregnancies with abnormal screening test

Objective. To investigate relationship between glycemic control in first half of pregnancy by measuring mid-pregnancy HbA1c and neonatal birth weight and amniotic fluid volume.Methods. We prospectively enrolled 220 pregnant women who received oral glucose tolerance test (OGTT) after positive gestational diabetes mellitus screening. We included 102 women with normal OGTT results into final analysis. We measured birth weight and amniotic fluid index (AFI) at 32–34 weeks.Results. Mean birth weight was 3313 ± 426 g, and 15.7% of neonates were classified as large-for-gestational age (LGA). Mean Hb1Ac was 4.96 ± 0.28%. Median AFI was 145 mm, and polyhydramnios rate was 2.9%. Birth weight was positively correlated with HbA1c level (r = 0.373, p < 0.001) and pre-pregnancy body mass index (BMI; r = 0.351, p < 0.001). Linear regression analysis showed that HbA1c and pre-pregnancy BMI were positive independent determinants of neonatal birth weight, and HbA1c was positive independent determinant of AFI. Receiver oper...