Observations in diabetic and non-diabetic pregnant women may help lead to an understanding of diabetes and the path to treatment. The hormones of human pregnancy are instrumental in protecting the fetal/placental unit from rejection. Dr. Jovanovic has described a phenomenon of apparent pancreatic rejuvenation during pregnancy in some type 1 diabetic women. These women show a rise in their C-peptide level and a drop in their insulin requirement. The C-peptide rise was in parallel with a rise in their pregnancy-related growth factors, specifically prolactin and human placental lactogen, and pregnancy related immunosuppressive hormones, specifically cortisol and progesterone.

Glucagon-Like Peptide-1 (GLP) has received considerable attention as a treatment for type 2 diabetes. Replacement of this naturally-occurring hormone in people with type 2 diabetes appears to improve glucose tolerance and insulin production, reduce glucagons secretion and gastric emptying and suppress the appetite in many patients. With a grant from the Lilly Corporation, Dr. Jovanovic and Dr. Howard Zisser are investigating whether women with gestational diabetes have reduced levels of GLP during their pregnancy compared to after they deliver their baby and also compared to non-diabetic pregnant women. If it can be shown that gestational diabetes is associated with a defect in GLP production, the next step would be to propose treatment with GLP during pregnancy.