Type 2 diabetes mellitus (DM) is associated with adverse perinatal outcomes, but insulin requirements and the prevalence of inadequate glycemic control across gestation are not well characterized. We therefore conducted a retrospective cohort study of women with type 2 DM who delivered from 2015 to 2017. Self-monitored blood glucose and insulin doses across gestation were abstracted, and inadequate glycemic control was defined as a mean blood glucose >95 mg/dL fasting or >140 mg/dL 1 hour post-prandial. We compared insulin dosing in early gestation and at delivery by maternal glycemic control. Multivariable logistic regression was used to identify predictors of high insulin requirements at delivery.
Inadequate glycemic control occurred in 96/155 (62%) of women. Maternal BMI, gestational age at first prenatal visit, and duration of diabetes were similar between women with inadequate and adequate control. Baseline HbA1c (8.1 ±2.0 vs. 7.5 ±1.9%, p=0.10) and percent of women receiving medical therapy before initiation of prenatal care (71.3% vs. 69.5%, p=0.81) were also similar between groups. Women with inadequate and adequate control had similar insulin doses in early pregnancy (0.7 ±0.5 vs. 0.7 ±0.5 units/kg, p=0.86), but by delivery women with inadequate control required significantly higher doses (2.3 ±1.2 vs. 1.8 ±1.0 units/kg, p=0.004). The highest quartile of insulin dose at delivery was >2.7 units/kg. Multivariable logistic regression modeling demonstrated that maternal BMI at the first prenatal visit (aOR 1.0, 95% CI 0.99-1.01), non-white race (aOR 0.35, 95% CI 0.16-0.78), and baseline HbA1c (aOR 1.22, 95% CI 1.02-1.46) had poor ability to predict high insulin requirements at delivery (AUC 0.67). Although high insulin requirements may be related to suboptimal glycemic control in women with type 2 DM, it is difficult to identify these women using baseline characteristics. Further studies are urgently needed to optimize insulin dosing in women with Type 2 DM.
H.C. Nadeau: None. M.E. Maxted: None. D. Madhavan: None. S. Pierce: None. M.N. Feghali: None. C.M. Scifres: None.