Insulin Therapy in Pregnant Women With Preexisting Diabetes

A recent review evaluated the evidence for insulin types and regimens for treating pregnant women with preexisting diabetes. The results were published in Cochrane Database of Systematic Reviews.¹

Pregnant women with type 1 diabetes may require 3 to 4 times the pre-pregnancy dose of insulin,² and some pregnant women with type 2 diabetes may need insulin therapy if they cannot achieve glycemic control with lifestyle management and oral hypoglycemic agents.^3-5 Pregnancy-related outcomes are worse in women with diabetes than in women without diabetes, and diabetes is becoming increasingly common in women of childbearing age.

In addition, new types of insulin and regimens have been developed, and their safety in pregnancy has not been established. The optimal insulin therapy strategies in pregnant women with preexisting diabetes are currently unknown.

In a systematic review, researchers evaluated the safety and efficacy outcomes in pregnant women with preexisting type 1 or type 2 diabetes who were treated with different insulin types and regimens.

A total of 554 women and newborns from 5 clinical trials were included for analysis. The researchers examined each trial separately, since the trials assessed different comparisons and the data could not be pooled.

A trial of 93 women investigated outcomes in patients receiving pre-mixed insulin (70 NPH/30 regular) vs self-mixed, split-dose insulin. Rates of macrosomia and caesarean section for cephalo-pelvic disproportion were similar for both interventions. The same study also compared insulin injected using a Novolin pen with insulin injected using a syringe and found that while rates of macrosomia did not differ, fewer women in the insulin pen group required caesarean section than women receiving syringe injections (risk ratio [RR], 0.38).

Other trials did not find any differences in outcomes for the insulin types and regimens studied. Treatment with lispro insulin vs regular insulin (n=33) resulted in similar rates of preeclampsia and caesarian sections (RR, 0.68). No difference in the incidence of macrosomia was observed with human insulin vs animal insulin (n=42; RR, 0.22). Major fetal anomalies occurred in similar numbers of infants born to women receiving insulin detemir and to women receiving NPH insulin (n=162; RR, 3.15).

Finally, a trial evaluating insulin aspart vs human insulin (n=223) did not record any of the review’s outcomes, which included birth trauma, fracture, macrosomia, and perinatal death.

“At present, insufficient data exist to … make any substantial or concrete conclusions about the effectiveness of one insulin type or regimen over another in pregnant women with preexisting type 1 or type 2 diabetes,” the researchers wrote. “Therefore, decisions about the use of different types of insulin and different insulin regimens for pregnant women with preexisting type 1 or type 2 diabetes should be made according to individual needs and available resources.”

Disclosures: Louise Kenney, MB ChB, PhD reports financial relationships with Alere and Metabolomic Diagnostics.

Reference

1. O’Neill SM, Kenny LC, Khashan AS, et al. Different insulin types and regimens for pregnant women with pre-existing diabetes. Cochrane Database Syst Rev. 2017;2:CD011880. doi:10.1002/14651858.CD011880.pub2 
2. McCance DR, Holmes VA. Insulin Regimens in Pregnancy. In McMcCance DR and Sacks DA, eds. A Practical Manual of Diabetes in Pregnancy. Oxford, UK: Wiley-Blackwell; 2010: doi:10.1002/9781444315196.ch10
3. Balaji V, Seshiah V. Management of diabetes in pregnancy. J Assoc Physicians India. 2011;59(Suppl):33-36.
4. Ballas J, Moore TR, Ramos GA. Management of diabetes in pregnancy. Curr Diab Rep. 2012;12(1):33-42. doi:10.1007/s11892-011-0249-0
5. NICE. Diabetes in pregnancy: management of diabetes and its complications from preconception to the postnatal period. Published February 2015. www.nice.org/uk/guidance/ng3. Last updated August 2015.