Management of Late-Term and Postterm Pregnancy.

Postterm pregnancy is defined as a pregnancy that has reached 42 weeks' gestation and late-term pregnancy includes 41 weeks' and 0 days' to 41 weeks' and 6 days' gestation. Accurate first-trimester dating is essential for determining or verifying gestational age. Ideal management of late-term and postterm pregnancy involves shared decision-making on timing of planned delivery based on risks and preferences. Starting at 42 weeks' gestation, the risks of fetal mortality, admission to the neonatal intensive care unit, and stillbirth increase exponentially. Induction of labor at 41 weeks' gestation reduces perinatal mortality and stillbirth compared with expectant management or induction starting at 42 weeks' gestation. Recent studies have shown a decrease in cesarean deliveries and hypertensive disorders of pregnancy with induction of labor in nulliparous, low-risk pregnancies beginning at 39 weeks' gestation. Induction of labor before 42 weeks' gestation decreases the risk of stillbirth, perinatal mortality, and cesarean delivery compared with expectant management. The American College of Obstetricians and Gynecologists suggests considering an elective induction of labor in low-risk, nulliparous patients starting at 39 weeks' and 0 days' gestation and recommends induction of labor in all patients by 42 weeks' gestation. The American College of Obstetricians and Gynecologists recommends antepartum monitoring of pregnancies beginning at 41 weeks' gestation to mitigate the risks of perinatal morbidity and mortality.