Gestational diabetes often crops up in the third trimester, but doctors are also troubled by the rising number of women who begin pregnancy as diabetics. The percentage who conceived with pre-existing diabetes— either type I, commonly known as “childhood diabetes,” or type II, often referred to as “adult onset diabetes”—more than doubled between 1999 and 2005, from 0.8 percent to 1.9 percent. This is likely due to high rates of obesity, which contributes to type II diabetes.
Any diabetes during pregnancy is linked to larger babies and the need for C-sections, but women with the pre-existing condition are also at risk for miscarriage, stillbirth and having a baby with birth defects. The cause may be elevated blood sugar during the crucial first trimester, when fetal organs are developing, says Jean M. Lawrence, Sc.D., M.P.H., of Kaiser Permanente’s Department of Research & Evaluation.