Insulin requirements in late pregnancy in women with type 1 diabetes mellitus: a retrospective review

Abstract

Pregnancy in women with type 1 diabetes mellitus (T1DM) is generally associated with increased insulin requirements.

Aims: To determine the frequency and significance of declining insulin requirements in late gestation in women with T1DM.

Methods: We conducted a retrospective review of 54 women seen at our institution from 2006 to 2010 with a diagnosis of T1DM pre-pregnancy and presentation for antenatal care prior to 28 weeks. Information was collected regarding patient demographics, insulin dose and pregnancy outcome. A 15% difference in weight-adjusted basal insulin from 30 weeks gestation to delivery was considered significant.

Results: Five women (9.3%) had a fall of 15% or more and 23 (42.5%) had a rise of 15% or more rise in insulin requirements. There were fewer neonatal intensive care admissions but more infants with an APGAR <8 at 5 min in women with a fall in insulin requirements. These differences were not evident when the data were re-analysed by quartiles of change.

Conclusions: In most women with T1DM, insulin requirements show little change from 30 weeks gestation until delivery. Almost 10% of women had a significant fall in insulin requirements which did not correlate with adverse neonatal outcome. These results require validation in a larger, prospective trial.