Preconception insulin treatment lessened hypoglycemia risk

Initiation of insulin analogue treatment before conception, as opposed to early in the pregnancy, may be safer for women with type 1 diabetes to avoid severe hypoglycemia, new data suggested.

An open-label, randomized, parallel-group, multinational, multicenter study included 332 adult women with type 1 diabetes. All women were insulin-treated for more than one year and were pregnant or planning a pregnancy.

Women were administered prandial insulin aspart 100 IU/mL (NovoRapid, Novo Nordisk) immediately before meals or human insulin 100 IU/mL/3 mL (Actrapid, Novo Nordisk) 30 minutes before each meal, in combination with NPH insulin 100 IU/mL/3 mL, one to four times per day.

Twenty-three percent of women experienced severe hypoglycemia during pregnancy, with most cases occurring in early pregnancy.

During the first half of pregnancy, the RR of severe hypoglycemia for women assigned to early pregnancy/preconception was 1.7 (95% CI, 0.91-3.18). During the second half of pregnancy, the RR was 1.35 (95% CI, 0.38-4.77).

Severe hypoglycemia rates for women assigned to prandial insulin aspart vs. human insulin were: 0.9 vs. 2.4 events per patient per year in preconception; 0.9 vs. 2.4 events per patient per year in the first half of pregnancy; 0.3 vs. 1.2 events per patient per year in the second half of pregnancy; and 0.2 vs. 2.2 episodes events per patient per year in postpartum.

“The reasons for this finding remain unclear, but might include the influence of preconception planning,” the researchers wrote. “Although the limitations of exploratory analyses prevent any firm conclusions, these data suggest another potential advantage of prenatal care that is worthy of further investigation.”

Heller S. Diabetes Care. 2010;33:473-477.