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 effecti
vely correct carbohydrate metabolism during diabetic pregnancy and 2) will
such therapy, if initiated before conception, eliminate diabetes-induced co
ngenital 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, nonfastin
g blood glucose (BG) determinations were made posttransplantation and throu
ghout pregnancy. Pups were delivered by cesarean section on day 19 of gesta
tion. Outcome parameters from transplanted animals (Tx) were compared to no
ndiabetic control animals and to untreated diabetic (DM) animals. Transplan
ted animals had significantly lower BG levels throughout pregnancy, compare
d with DM animals, but also had levels that were often lower than those see
n in control nondiabetic animals, and had increased episodes of documented
hypoglycemia. The malformation and fetal loss rate in the Tx group was sign
ificantly 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 ma
y play in producing increased episodes of hypoglycemia or specific congenit
al malformations in pregnancy must be thoroughly investigated before any cl
inical studies.