Insulin requirements in type 1 diabetic pregnancy: do twin pregnant women require twice as much insulin as singleton pregnant women?

Abstract

To evaluate the insulin requirements in women with type 1 diabetes during twin pregnancy compared with singleton pregnancy. At 8, 14, 21, 27, and 33 gestational weeks, insulin requirements and HbA(1c) were compared between 15 twin pregnant women from 2000 to 2011 and 108 singleton pregnant women from 2004 to 2006. In twin pregnancies, the weekly increase in daily insulin dose between 14 and 27 weeks was higher than in singleton pregnancies (median 3.0 international units [IU] [range 0.9-4.9] versus 1.5 IU [-1.5 to 5.9]; P = 0.008) and remained stable from 27 to 33 weeks. The increment in total insulin requirement from before pregnancy until 33 weeks tended to be higher in twin pregnancies (103% [36-257%] versus 71% [-20 to 276%]; P = 0.07). Throughout pregnancy, HbA(1c) was similar in twin and singleton pregnancies. In twin pregnancies, the weekly increase in insulin dose between 14 and 27 weeks was doubled compared with singleton pregnancies.