Endocrine Abstracts

Background: Hyperglycemia is believed to be the underlying cause for many of the adverse fetal, neonatal, and maternal outcomes in pregnancies complicated by type 1diabetes (T1DM). In particular, the rates of a large for gestational age (LGA) neonates and macrosomia remain high and suggest that hyperglycemia may not be the only driver of fetal overgrowth for women with T1DM.

Aim: Our aim was to assess the association between gestational glycemic profiles [HbA1c, postprandial (PG), fasting (FG), mean (MG) blood glucose]and delivery with a LGA baby in women with T1DM.

Methods: Totally, 321 pregnant women with T1DM were enrolled in the study. Data obtained for home-blood glucose monitoring (seven-point profiles), PG, FG, MG and HbA1c in the late 2nd and 3rd trimesters of pregnancy were analyzed. Gestational age at delivery was 37.2 ± 1.3 weeks and birth weight (BW) was 3 383 ± 358.3 g; in total, 86 (26%) neonates were born LGA. The patients were divided into 2 groups (Gr.): LGA-Gr. – 86 patients and non-LGA-Gr. – 235 patients.

Results: In the late 2nd and 3rd trimesters of pregnancy HbA1c, PG, FG and MG levels were statistically higher in LGA-Gr., than in non-LGA-Gr.: HbA1c (%) −7.3 ± 1.29 vs 6.2 ± 1.63 (P<0.001); PG (mg/dl) – (P = 0.000); FG (mg/dl) – (P = 0.000); MG (mg/dl)- (P = 0.000). Pre-pregnancy body mass index (BMI) was higher in LGA-Gr, than in non-LGA-Gr. (kg/m²) – 27.5± 0.57 vs 22.9± 0.41 (P <0.001). In non-LGA-Gr. correlation between body weight (BW) and PG (r −0.794; P = 0.000) and BW and pre-pregnancy BMI (r −0.580; P = 0.0076) was observed, thoughno significant interaction betweeninfants BW and HbA1c, FG and MG was found.

In LGA-Gr. strong correlation between BW and PG (r −0.876; P = 0.000), BW and HbA1c (r −0.603; P = 0.003), BW and MG (r −0.611; P = 0.002), BW and pre-pregnancy BMI (r −0.866; P = 0.001), and no correlation between BW and FG were observed.

Conclusion: HbA_1c is less likely to be able to detect shorter-term glucose variability and does not always predict fetal macrosomia. Maternal postprandial glucose excursions in the late 2nd and 3rd trimesters and pre-pregnancy BMI might be relevant in the development of aLGA baby.