Before diabetes mellitus could be treated with insulin, it was rarely seen during pregnancy and was associated with high maternal and fetal mortality. After insulin became available, in 1922, pregnant women with diabetes had better outcomes, but fetal and neonatal deaths remained common. In the mid 20th century, Jorgen Pedersen observed that glucose readily crossed the placenta. This lead to the critically important maternal hyperglycemia – fetal hyperinsulinemia – diabetes associated fetopathy (large fetal size, excess body fat and newborn hypoglycemia. Pedersen and others soon demonstrated that with the assistance of a team with medical, obstetric, nutritional and pediatric expertise employing liberal use of hospitalization outcome of pregnancy in women with diabetes could be greatly improved. However, at the time the diabetes and pregnancy center (DPC) was organized at Northwestern University nearly 50 years ago, we found it challenging to convince women with pre-existing diabetes that with meticulous effort and cooperation of patients and the healthcare team, favorable pregnancy outcome was achievable. Many had been advised to avoid pregnancies.
Since that time, major technological changes have become available to assist in the achievement of more optimal metabolic control of diabetes in and outside of pregnancy. In 1989, the IDF/WHO Europe St. Vincent declaration set as goal, in all pregnancies complicated by diabetes, perinatal and long-term outcomes similar to women without diabetes. This has been a challenging goal. The number of pregnancies in all types of diabetes in pregnancy, T1DM, T2DM and GDM has increased. The parallel increase in rates of obesity in all ages of the population is an important contributor to this demographic.
In 2015, Jovanovic, et al (Diabetes/Metabolism Research and Reviews, 31:707-16, 2015) used health claims from a database of 839,792 pregnancies to compare outcomes where diabetes status could be ascertained. Diabetes was present in 7.86%; T1DM 0.13%, T2DM 1.21% and GDM 6.29%). Those defined as GDM during pregnancy but with T2DM postpartum (progressing to T2DM) represented another 0.23%. Significantly higher rates of many pregnancy, neonatal and maternal outcomes were found in 1 or more of the groups listed above. Medical costs were also greater for mothers with compared to those without diabetes, especially for T1DM (nearly doubled). Thus, more than 25 years after the St. Vincent declaration, the goals for pregnancy outcome in mothers with diabetes have not be achieved.
Early in the 21st century new advances in insulin delivery and continuous glucose monitoring techniques offer new hope for an effective “artificial pancreas” and true optimal control of hyperglycemia.