Flat Oral Glucose Tolerance Test During Pregnancy: Maternal Characteristics and Risk for Adverse Outcomes.

Flat oral glucose tolerance test (OGTT) curve is characterized by low glucose levels, seemingly nonresponsive to glucose load. Few studies have explored flat OGTT during pregnancy and have yielded conflicting results, some suggesting risk for fetal growth restriction. This study evaluated the characteristics and perinatal outcomes of women with a flat OGTT during pregnancy. We found that a flat OGTT curve occurs in younger, leaner pregnant women. Also, flat OGTT curve was significantly associated with a male fetus and higher levels of pregnancy-associated plasma protein A at the first-trimester screening. Although flat OGTT can possibly reflect some degree of hyperinsulinemia, it is generally not associated with adverse maternal or neonatal outcomes.