Congenital Malformation Rate in Offspring of Mother With Type 1 Diabetes Treated with Insulin Glargine During Pregnancy: A National Survey

Results: The long-acting insulin analog glargine (IAG) is largely used as a basal-bolus regimen in type 1 diabetes mellitus (T1DM), but its use is not still recommended during pregnancy. We promoted a national, multicentre, retrospective study to determine the rate of congenital malformation in a large group of offspring of mothers with T1DM who were treated with IAG before and during pregnancy, We collected 98 TIDM pregnancies from 26 Italian centres (age 30.6±4.6 years, diabetes duration 16.1 ±7.8 years, White's Classes B n=21, C=24, D=36, R=16, RF=1). IAG was started 11.1±10.7 months before conception as a basal-bolus regimen with an average dose of 18.7±7.1 IU/die. The pregnancy was unplanned in 92% of cases and the first diabetes assessment occurred at 8.5±4.1 week (HbA1c 7.7±1.3%, range 5.3-13.8%). IAG was continued until the end of pregnancy in 36% of case, while it was stopped during the first trimester of gestation in 64%. Glycemic control was improved during pregnancy with a mean HbA1c at the end of pregnancy of 6.5±0.86%. Spontaneous and elective abortions occurred in 4 and 2 women respectively. 92 babies were delivered at 36.7±2.1 week (pre-term deliveries 29.9%, casearean sections 81.1%) with mean birth weight of 3298 ±732 g (LGA 42.1%). Congenital malformations (CM) were reported in 5 newborns (5.4%), involving cardiovascular (n.2), genitourinary system (n.2), and syndactylia (n.1). The rate of CM is not different from that reported in other studies regarding pregnancies of T1DM women treated with other insulins. Our survey, performed in a large cohort of T1DM pregnant women, suggest that insulin glargine does not seem to affect embryo-fetal development.