Effective prenatal care should integrate the best available evidence into a model of shared decision making. Pregnant women should be counseled about the risks of smoking and alcohol and drug use. Structured educational programs to promote breastfeeding are effective. Routine fetal heart auscultation, urinalysis, and assessment of maternal weight, blood pressure, and fundal height generally are recommended, although the evidence for these interventions is variable. Women should be offered ABO and Rh blood typing and screening for anemia during the first prenatal visit. Genetic counseling and testing should be offered to couples with a family history of genetic disorders, a previously affected fetus or child, or a history of recurrent miscarriage. All women should be offered prenatal serum marker screening for neural tube defects and aneuploidy. Women at increased risk for aneuploidy should be offered amniocentesis or chorionic villus sampling. Counseling about the limitations and risks of these tests, as well as their psychologic implications, is necessary. Folic acid supplementation beginning in the preconception period reduces the incidence of neural tube defects. There is limited evidence that routine use of other dietary supplements may improve outcomes for the mother and infant.