Endocrine Abstracts

Background: Previous studies evaluating the association between falling insulin requirements (FIR) during late pregnancy and adverse maternal and neonatal outcomes yielded controversial results.

Methods: We conducted a retrospective cohort analysis of data collected from women delivering at Shamir Medical Center (a referral university-affiliated facility in central Israel), between 2008–2018. The percent of FIR was calculated by dividing the remainder between the peak total insulin dose during the third trimester and the trough total insulin dose following that peak dose by the highest insulin dose. We compared women with FIR <15% to those with FIR >15% in regard with a composite outcome of any of the following maternal or neonatal complications: Cesarean-section due to fetal distress, pre-eclampsia, induction of labor due to intra-uterine-growth-retardation, small-for-gestational-age or fetal acidemia (cord blood PH <7.2).

Results: In the final analysis, we included 87 pregnancies in 80 women. Sixteen (18.4%) women had a more than 15% FIR during the 3rd trimester. There were 27 women (31%) who had T1DM and the rest T2DM. Women with FIR >15% had lower pre-gestational body mass index (BMI) at baseline (24.9 ± 4.43 vs 28.16 ± 5.79 kg/m² P = 0.049). Women having >15% FIR also had significantly more hypoglycemic episodes during pregnancy though there were no differences in severe hypoglycemia. Composite outcome occurred in 5 (31.3%) deliveries in women with FIR >15% and in 29 (40%) of deliveries in women with FIR <15% P = 0.47. There were no significant differences in all other maternal or neonatal outcomes in women with FIR ≥15% compared with FIR <15%.

Conclusions: FIR during the 3rd trimester occurs in a considerable number of diabetic women. In our cohort of women with pregestational diabetes (T1DM and T2DM), 3rd trimester FIR was associated with increased risk for maternal hypoglycemia during pregnancy but not with other adverse maternal or neonatal outcomes.