Women with high glucose readings early in pregnancy are at increased risk of having a baby with heart defects, even if they do not have full-blown diabetes, a new study found. Diabetes during pregnancy is a known risk factor for heart problems in babies.
Researchers studied data on 19,107 mothers, members of two large health care systems, of whom 811 gave birth to babies with congenital heart disease. The data included blood glucose measurements done between four weeks before conception and the 14th week of gestation.
The heart develops very early in pregnancy. The fetal heart begins to beat at about three weeks after conception, and by the eighth week of gestation it has clearly developed chambers.