Glycemic control and maternal and fetal outcomes in pregnant women with type 1 diabetes according to the type of basal insulin.

To examine the potential role of the type of basal insulin on glycemic control and maternal and foetal outcomes in pregnant women with type 1 diabetes (T1DM). Retrospective cohort study of pregnancies attended at 18 Spanish tertiary hospitals. T1DM, singleton pregnancies, delivery between 2002-2010, and use of the same basal and prandial insulin from before pregnancy until delivery. A total of 1534 pregnancies were included. The basal insulin most commonly used was Neutral Protamine Hagedorn (NPH) (51.7%), followed by glargine (23.2%) and continuous subcutaneous insulin infusion (CSII) (21.1%). CSII users had longer diabetes duration. Multiple logistic regression analysis showed that CSII was independently associated with lower doses of insulin, higher glycated haemoglobin (HbA1c) in all trimesters, and higher rates of miscarriage, preterm birth and neonatal hypoglycemia. Glargine was related to a higher risk of preterm birth and a small-for-gestational age infant (SGA). The odds ratios (OR) of the associations between insulin type and clinical outcomes (from 0.642 to 4.894) have a relevant magnitude. In this observational study of pregnant women with T1DM, the type of basal insulin was independently associated with metabolic variables and foetal outcomes.