Individualizing the Risk for Preterm Birth
Epidemiologic studies have shown that pregnancies carrying a male fetus have a higher incidence of preterm birth, and this male-female difference is more prominent in early preterm birth.
Multiple gestations result in 15–20% of all preterm births. Nearly 60% of twin are born preterm. Using the data from National Center for Health Statistics, about 50% of preterm births were indicated; one-third of the births were spontaneous and 10% of the births occurred after preterm premature rupture of the membranes (PPROM). Of twin gestations with symptoms of preterm labor, about 22–29% of the pregnancies will deliver within 7 days. Nearly all higher multiple gestations will result in preterm delivery.
Uterine over distension, resulting in contractions and PPROM, is believed to be the causative mechanism for the rate of increased spontaneous preterm births. The dichorionic triamniotic triplets have a higher risk of delivery at <30 weeks of gestation (OR: 4.6; 95% CI: 1.6–11.8) compared to trichorionic triplets. The dichorionic triamniotic triplets have a 5.5-fold higher risk of adverse perinatal outcome predominantly because of twin–twin transfusion syndrome and premature rupture of membranes (PROM), followed by spontaneous preterm birth.
Fetal Characteristics
Fetal Gender
Epidemiologic studies have shown that pregnancies carrying a male fetus have a higher incidence of preterm birth, and this male-female difference is more prominent in early preterm birth.
Fetal Number & Chorionicity
Multiple gestations result in 15–20% of all preterm births. Nearly 60% of twin are born preterm. Using the data from National Center for Health Statistics, about 50% of preterm births were indicated; one-third of the births were spontaneous and 10% of the births occurred after preterm premature rupture of the membranes (PPROM). Of twin gestations with symptoms of preterm labor, about 22–29% of the pregnancies will deliver within 7 days. Nearly all higher multiple gestations will result in preterm delivery.
Uterine over distension, resulting in contractions and PPROM, is believed to be the causative mechanism for the rate of increased spontaneous preterm births. The dichorionic triamniotic triplets have a higher risk of delivery at <30 weeks of gestation (OR: 4.6; 95% CI: 1.6–11.8) compared to trichorionic triplets. The dichorionic triamniotic triplets have a 5.5-fold higher risk of adverse perinatal outcome predominantly because of twin–twin transfusion syndrome and premature rupture of membranes (PROM), followed by spontaneous preterm birth.