Aim:
To determine the association between the degree of falling insulin requirements and placental insufficiency related adverse outcomes in pregnancies of women with pre-existing diabetes.
Method:
A retrospective medical record review of all women with pre-existing diabetes on insulin who birthed at a regional hospital in Queensland, Australia over a 5-year period. We collected demographic information, insulin peak and trough daily dose to determine falling insulin requirements, maternal and neonatal outcomes.
Results:
Of 184 women 85% had type 2 diabetes. Fifty-nine (32%) women had a fall in insulin requirements (FIR): 19 (10.3%) had FIR <15%, 13 (8.2%) had FIR 15-49% and 25 (13.6%) had FIR of ≥ 50%. Across all degrees of falling insulin requirement, there was an association with features of placental insufficiency including severe pre-eclampsia, OR (95%CI) 3.9 (1.04-14.5 ), 7.3 (2.0-26.5), 9.7 (3.3-28.5) in groups FIR<15%, 15-49%, ≥ 50% compared to no FIR respectively. Mothers affected by FIR had longer hospital length of stay(4.8 days SD 2.7 vs 3.9 days SD 1.7, p<0.01).
There was an association with FIR and neonatal outcomes including APGAR <7 at 5mins (FIR <15% OR 8.0 (2.1-30.1), FIR 15-49.9 OR 1, FIR ≥ 50% OR 2.6 (0.6-11.2) and respiratory distress (FIR <15% OR 3.6 (1.3-10.3) p<0.05) FIR 15-49.9 OR 1.2 (0.3-4.0), FIR ≥ 50% 2.2 (0.9-5.3)).
Conclusion: In women with pre-existing diabetes, any degree of fall in insulin requirement is associated with adverse maternal and neonatal outcomes related to placental dysfunction and should prompt urgent evaluation.