A comparison of the safety and effectiveness of insulin aspart with other bolus insulins in women with pre-existing Type 1 diabetes during pregnancy: A post hoc analysis of a prospective cohort study

Aims

The safety and efficacy of insulin analogue insulin aspart (IAsp) have been demonstrated in a randomised clinical trial in pregnant women with Type 1 diabetes (T1D), and IAsp is widely used during pregnancy. The aim of this study was to assess glycaemic control and safety of IAsp versus other bolus insulins in Type 1 diabetic pregnancy in a real-world setting.

Methods

This was a post hoc analysis of a prospective cohort study of 1840 pregnant women with T1D, treated with IAsp (n = 1434) or other bolus insulins (n = 406) in the Diabetes Pregnancy Registry. The primary (composite) outcome was the proportion of pregnancies resulting in major congenital malformations or perinatal or neonatal death. Secondary outcomes included all HbA_1c values measured immediately before and during pregnancy and major hypoglycaemia, as well as abortion, pre-eclampsia, pre-term delivery, large for gestational age at birth, stillbirth and fetal malformations.

Results

There were no significant differences found in any of the pregnancy outcomes between treatment with IAsp and other bolus insulins in either the crude or propensity score-adjusted analyses. However, maternal HbA_1c was lower in the IAsp group at the end of the third trimester (adjusted difference, −0.16% point [95% CI −0.28;−0.05]; −1.8 mmol/mol [95% CI −3.1;−0.6]; p = 0.0046).

Conclusions

No significant differences in safety or pregnancy outcomes were demonstrated when comparing treatment with IAsp versus other bolus insulins in women with T1D during pregnancy. The observed improvement in HbA_1c with IAsp in late pregnancy should be confirmed in other studies.