gynecology and obstetrics
Postterm Pregnancy
Introduction
Postterm pregnancy refers to gestation that lasts≥42 (> 41 6/7) weeks. Late-term pregnancy is defined as 41 0/7 to 41 6/7 weeks. Antenatal surveillance should be considered at 41 weeks. Induction of labor should be considered after 41 weeks and is recommended after 42 weeks. Accurate gestational age estimation is essential in making a diagnosis of postterm pregnancy. In women with regular, normal menstrual cycles, gestational age can be estimated based on the first day of the last normal menstrual period. If dating is uncertain or inconsistent with menstrual dating, ultrasonography early in gestation (up to 20 weeks) is the most accurate with accepted variation of+/−7 days. Later in gestation, the variation increases to+/−14 days at 20 to 30 weeks gestation and+/−21 days after 30 weeks. Postterm pregnancy increases risks for the woman and fetus. Risks include Abnormal fetal growth ( Large-for-Gestational-Age (LGA) Infant and Oligohydramnios None Meconium-stained amniotic fluid Nonreassuring fetal test results Fetal and neonatal death Need for neonatal intensive care Dystocia (abnormal or difficult labor) Cesarean Delivery None Operative Vaginal Delivery None Perineal lacerations Postpartum Hemorrhage None Postterm Infants None Antenatal surveillanceshould be considered at 41 weeks; it involves one of the following: Nonstress testing Modified biophysical profile (nonstress testing and assessment of amniotic fluid volume) A full biophysical profile (assessment of amniotic fluid volume and fetal movement, tone, breathing, and heart rate) 