The purpose of this study was to evaluate the feasibility and effectiveness of Bioartificial Pancreas (BAP) technology use during diabetic pregnancy. In particular, the study asked 1) can microencapsulated islet cells effectively correct carbohydrate metabolism during diabetic pregnancy and 2) will such therapy, if initiated before conception, eliminate diabetes-induced congenital malformations in the fetus? Streptozotocin-induced diabetic female mice (ICR) received transplants of rat islets encapsulated within alginate microbeads. Animals were placed with male mice and bred. Random, nonfasting blood glucose (BG) determinations were made posttransplantation and throughout pregnancy. Pups were delivered by cesarean section on day 19 of gestation. Outcome parameters from transplanted animals (Tx) were compared to nondiabetic control animals and to untreated diabetic (DM) animals. Transplanted animals had significantly lower BG levels throughout pregnancy, compared with DM animals, but also had levels that were often lower than those seen in control nondiabetic animals, and had increased episodes of documented hypoglycemia. The malformation and fetal loss rate in the Tx group was significantly lower than the untreated group (ICR: 5.4% vs. 40%). Only 3 of 84 pups from the Tx group had major malformations, but all had anencephaly, a malformation not seen in any other study group. Both maternal BG levels and fetal malformation rates are significantly reduced using BAP technology in our animal models. However, the possible role these encapsulated islets may play in producing increased episodes of hypoglycemia or specific congenital malformations in pregnancy must be thoroughly investigated before any clinical studies.
