The prenatal care provider needs to determine whether pregnant individuals or those contemplating pregnancy are at risk for offspring with genetic abnormalities or birth defects, including those caused by environmental exposures. A carefully elicited medical, genetic, family, and personal history will give important information about potential genetic problems. All pregnant individuals and those considering a future pregnancy should be offered carrier screening for cystic fibrosis, spinal muscular atrophy, and hemoglobinopathies (American College of Obstetricians and Gynecologists [ACOG], 2017a). A referral to a genetic counselor is essential when patients are at risk for genetic problems. All patients may wish to consider preconception and/or prenatal screening or diagnostic tests to determine risk to their offspring. If a patient requests repeat screening, ACOG recommends referral to a provider with genetics expertise to review previous results and determine the benefits and limitations of the request for subsequent rescreening.