Posttermsynnytykset

Posttermsynnytykset, or postterm pregnancy, describe pregnancies that extend beyond 42 completed weeks of gestation (294 days from the first day of the last menstrual period) or beyond the due date used by clinicians. The term postmaturity is sometimes used to refer to the newborn condition that can follow prolonged gestation. Postterm pregnancy is distinct from late preterm and term pregnancies and from postmaturity syndrome in the newborn.

Epidemiology and risk factors: Most pregnancies end before 42 weeks. The proportion of postterm pregnancies varies with obstetric practice and surveillance strategies, but a minority of pregnancies reach or exceed 42 weeks. Risk factors include nulliparity, advanced maternal age, obesity, prior postterm pregnancy, and certain uterine or placental conditions. Fetal chromosomal abnormalities and maternal medical conditions can influence timing of delivery as well.

Complications: Prolonged gestation increases the risk of placental aging with reduced oxygen and nutrient delivery. Fetal complications can include oligohydramnios, meconium-stained amniotic fluid, fetal distress, and an elevated risk of stillbirth after 41 weeks. For the mother, postterm pregnancy is associated with longer, less efficient labor and a higher rate of cesarean delivery and postpartum hemorrhage.

Management: Care involves regular fetal monitoring and assessment of fetal well-being and amniotic fluid. Many guidelines recommend planning delivery around 41 weeks or earlier if there are risk factors or signs of compromised fetal status, with individual decisions made in consultation with the patient. Induction of labor commonly uses cervical ripening agents followed by oxytocin, aiming for a vaginal delivery when possible. If induction fails or complications arise, cesarean delivery may be considered.

Outcomes: With appropriate surveillance and timely delivery, adverse outcomes can be reduced, though risks increase with advancing gestational age. Counseling and shared decision-making are central to management.