Aim: To determine the rate of major congenital anomalies in offspring of a large group of women with diabetes mellitus treated with insulin lispro (Humalog).
Methods: This multinational, multicentre, retrospective study included mothers with diabetes mellitus (diagnosed prior to conception) who were treated with insulin lispro for at least 1 month before conception and during at least the first trimester of pregnancy. Anomalies were assessed by two independent dysmorphologists not affiliated with the sponsor.
Results: The charts of 496 women were reviewed for 533 pregnancies resulting in 542 offspring (500 live births, 31 spontaneous and seven elective abortions, and four stillbirths). Mothers' characteristics: mean (+/- SD) age was 29.9 (+/- 5.2) years, 85.6% were Caucasian and 97.2% had Type 1 diabetes mellitus. Insulin lispro continued to be the main mealtime insulin for more than 96% of the women during the second and third trimester. The dysmorphologists determined that 27 (5.4%) offspring had major congenital anomalies and 2 (0.4%) offspring had minor congenital anomalies.
Conclusions: The rate of major congenital anomalies was 5.4% [95% CI (3.45%, 7.44%)] for offspring of mothers with diabetes mellitus treated with insulin lispro before and during pregnancy. The current published rates of major anomalies in infants born to mothers with diabetes treated with insulin are between 2.1 and 10.9%. This suggests that the anomaly rate with insulin lispro treatment does not differ from the published major congenital anomaly rates for other insulin treatments.