The utility of HbA1c for screening gestational diabetes mellitus and its relationship with adverse pregnancy outcomes

AIMS

To evaluate the utility of glycated hemoglobin A1c (HbA1c) for screening gestational diabetes mellitus (GDM) and analyze its association with adverse pregnancy outcomes in a cohort of pregnant women.

METHODS

Women with singleton pregnancies, who completed a 2h oral glucose tolerance test (OGTT) and HbA1c test at gestational week 24-28 were enrolled in this retrospective study. Clinical information was obtained and statistical analyses were performed to assess the diagnostic value of HbA1c for GDM and the association of HbA1c with adverse pregnancy outcomes.

RESULTS

Of the 1959 pregnant women enrolled in the study, 413 were diagnosed with GDM. A HbA1c cutoff value <4.8% (29mmol/mol) showed adequate sensitivity to exclude GDM (85.0%) but low specificity (31.8%). While HbA1c cutoff value ≥5.5% (37mmol/mol) presented adequate specificity (95.7%) but low sensitivity (14.8%) in diagnosing GDM. Adoption of HbA1c as a screening test for GDM could eliminate the need for an OGTT in 34.7% women in our study, however, with 6.5% being wrongly diagnosed. HbA1c level was significantly associated with the risk of preterm delivery, neonatal hyperbilirubinemia, and neonatal asphyxia.

CONCLUSIONS

Whether adoption of HbA1c as a screening test for GDM would benefit pregnant women remains to be determined. However, HbA1c might be a useful tool to predict patients at increased risk of several adverse pregnancy outcomes.

Size at birth and insulin-like growth factor-I and its binding protein-1 among infants of diabetic mothers

OBJECTIVE

to estimate the association between intrauterine fetal growth, evaluated by anthropometric measurements, and biochemical growth factors; IGF-I and IGBP-1 among IDMs.

METHODS

Cross-sectional study carried out on 69 full term IDMs who was admitted to neonatal intensive care units, Ain Shams University Hospitals. Clinical examination including anthropometric measurements; birth weight, length, head circumference, mid-arm circumference, skinfold thickness at triceps and subscapular areas and placental weight. Laboratory investigations included maternal HbA(1c) and cord blood IGF-I and IGBP-1. They were classified into three groups: 20 small for gestational age (SGA), 25 appropriate for gestational age (AGA) and 24 large for gestational age (LGA).

RESULTS

Most of SGA neonates were born to mothers with type I diabetes, while most of AGA and LGA were born to mothers with gestational diabetes. According to maternal HbA(1c), SGA and LGA neonates were born to metabolically uncontrolled mothers while AGA neonates were born to well-controlled diabetic mothers. Anthropometric measurements had significant positive correlations with IGF-I and negative correlations with IGFBP-1.

CONCLUSIONS

Good control of diabetes during pregnancy is essential to improve fetal growth. There is an opposing effect of cord blood IGF-I and IGFBP-1 on anthropometric measurements.