(582) Basal insulin type and neonatal outcomes: a secondary analysis of the MOMPOD trial

Objective: A variety of basal insulin types (e.g. intermediate vs long-acting) are available for managing diabetes in pregnancy, however, the optimal choice of basal insulin remains uncertain in those with Type 2 diabetes (T2D) and diabetes diagnosed in early pregnancy (eDM). We aimed to compare neonatal outcomes according to basal insulin type.

Study Design: A secondary analysis of a randomized trial comparing the addition of metformin versus placebo in insulin treated pre-existing T2D or eDM at < 23 weeks. Included were those using either intermediate or long-acting insulin at randomization, though specific insulin types were not recorded. The primary outcome was a composite of newborn complications (Table 2). Categorical variables were compared between those on intermediate versus long-acting insulin using Chi-square or Fisher’s exact test, and continuous variables using t-test or Wilcoxon rank sum test. Logistic regression estimated the association between the basal insulin type and the composite outcome. Adjustments were made for confounding.

Results: A total of 812 participants were included in the analysis, 485 (59.7%) treated with intermediate and 327 (40.2%) with long-acting insulin. There were several demographic differences between the groups (Table 1). The primary neonatal composite outcome was less common among participants treated with intermediate insulin (65.8% vs 72.8%, p=0.035); however, after adjusting for confounders, there was no significant association (Table 2). There were no associations between basal insulin type and the individual components of the composite outcome. A post hoc power analysis confirmed that the study had sufficient power to detect a 10% difference in the primary outcome.

Conclusion: In participants with T2DM and eDM, while basal insulin choice varied by maternal characteristics there was no significant difference in neonatal outcomes. Consistent with a shared decision making model, providers and patients can be reassured that their choice of basal insulin can be based on preference and/or insurance coverage without concerns for adverse nor varying neonatal outcomes.