Efficacy of insulin lispro in pregnancies complicated with pregestational diabetes mellitus

Insulin is the mainstay in the management of pregnancies complicated by pregestational diabetes. Insulin analogues are useful in the non-pregnant state, leading to better glycaemic control. Our study tested the hypothesis that using insulin lispro in such pregnancies would lead to better feto-maternal outcome when compared to human insulin. The study was conducted as a retrospective case-control study, and was undertaken in the antenatal clinic of Lancashire Teaching Hospitals NHS Trust between 1997 and 2001. The study involved 153 consecutive women with pregestational diabetes, 83 of whom were treated with insulin lispro and the rest with human insulin. Details of their management and outcome were derived from their medical, obstetric and paediatric notes. The main outcome measures were: maternal glycaemic control at term, conclusion of pregnancy, Caesarean section rate, birth weight, neonatal intensive care unit (NICU) admission, neonatal jaundice, congenital anomalies and neonatal hypoglycaemia. There was a significant improvement in HbA1c at term in the group treated with insulin lispro (-0.75%, [-1.04 to -0.46]) when compared with the human insulin group (-0.18%, [-0.47 to 0.11]); p=0.005. This was not associated with a significant difference in feto-maternal outcome, apart from a higher NICU admission rate in the insulin lispro group. This adverse effect disappeared after adjusting for other co-variates. Hence, when compared to human insulin, insulin lispro provides better glycaemic control, without adversely affecting feto-maternal outcomes in pregnancy complicated with pregestational diabetes, which may be reflected in a better developmental outcome in the children.