Abstract
BACKGROUND When a woman becomes pregnant, the placenta produces human placental lactogen (hPL). The anti-insulin effect of hPL raises maternal blood glucose levels, allowing the fetus to use glucose as a nutrient. Because hPL is produced by the placenta until delivery, insulin requirements in patients with gestational diabetes mellitus (GDM) typically increase, but in some cases, they may decrease. We retrospectively examined data from women with GDM who received insulin and delivered at our hospital. CASE REPORT From April 2019 to March 2020, we targeted patients who were diagnosed with GDM, received insulin, and delivered at our hospital. GDM was diagnosed based on the guidelines from the Japanese Society of Obstetrics and Gynecology. The rate of change in insulin dosage was calculated as: (insulin dosage at delivery - insulin dosage 14 days before delivery) divided by 14. Two patients whose insulin dosage was significantly reduced developed a syndrome of hemolysis, elevated liver enzymes, and low platelet count or acute fatty liver of pregnancy and underwent emergency cesarean section. CONCLUSIONS The present case report suggests that a decrease in insulin requirement in pregnant patients with GDM can predict maternal abnormalities due to placental dysfunction.