In the first trimester, patients should have an ultrasonogram assessment (including measurement of crown-rump length) for pregnancy dating and viability. Consider nuchal translucency if the fetus is at high risk for cardiac defects (eg, because of high maternal glycohemoglobin)

In the second trimester, perform a detailed anatomy ultrasonogram at 18-20 weeks, and a fetal echocardiogram if the maternal glycohemoglobin value was elevated in the first trimester.

In the third trimester, perform a growth ultrasonogram to assess fetal size every 4-6 weeks from 26 to 36 weeks in women with overt preexisting diabetes. Perform a growth ultrasonogram for fetal size at least once at 36-37 weeks for women with gestational diabetes mellitus. Consider performing this study more frequently if macrosomia is suggested.


If maternal diabetes is longstanding or associated with known microvascular disease, obtain a baseline maternal electrocardiogram (ECG) and echocardiogram.


Consider an amniocentesis for the fetal lung profile if delivery is contemplated before 39 weeks’ gestation.