Insulin requirements during pregnancy in women with type 1 diabetes treated with insulin pump

Insulin requirement in women with Type 1 diabetes (T1DM) changes throughout pregnancy. The aim of this study was to determine the total change in insulin requirements and the effect of gestational weight gain (GWG) and pre-gestational BMI on insulin requirements during pregnancy in women with T1DM treated with continuous subcutaneous insulin infusion and continuous glucose monitoring.

This historical cohort study included all consecutive women with T1DM who were monitored during pregnancy at the high-risk pregnancy clinic at a tertiary medical center during April 2011-April 2019. One Way Repeated Measures ANOVA with Bonferroni adjustment was conducted to compare the effects of gestational age on insulin requirements and a Two Way Repeated Measures ANOVA was employed to test for the interaction between gestational age intervals and maternal BMI and GWG.

Data regarding insulin requirements of 185 pregnancies were included in the analyses. There was a significant effect of gestational age on total insulin (Wilks' Lambda = 0.34, F(6,14) = 4.52, p = 0.009), basal insulin (Wilks' Lambda = 0.41, F(6,14) = 3.30, p = 0.031) and bolus insulin (Wilks' Lambda = 0.43, F(6,14) = 3.02, p = 0.041). Total insulin/kg requirements increased by 5.5% from 13-20 weeks to 20-26 weeks, 19% from 20-26 weeks to 26-33 weeks, and 17.4% from 26 to 33 weeks to delivery (p for trend = 0.009). Overall, insulin requirements increased by 42.1% from conception to delivery (p < 0.01). There was no significant main effect of maternal BMI or GWG on insulin requirements.

There is a significant increase in insulin requirements per kg during pregnancy in women with T1DM who were treated with an insulin pump.