To investigate the maternal and fetal outcomes of super-advanced age pregnant women with different timing of pregnancy termination.

The data of 160 super-advanced age pregnant women who have labored at the First People Hospital of Foshan from February 2016 to January 2019 were retrospectively collected. The subjects were divided into either a post-term pregnancy group (n=33) or a term pregnancy group (n=127) based on the labor′s gestational age. The post-term pregnancy group had a gestational age between 40 and 41 weeks, and the term pregnancy group had a gestational ages between 37 and 39^{+ 6} weeks. Age, duration since previous pregnancy, hemoglobin levels before delivery, and body mass index at the labor′s gestational age were compared between the two groups by t-tests. Direct cesarean section rate, rate of conversion of vaginal trial to cesarean delivery, rate of vaginal midwifery, vaginal birth rate, postpartum hemorrhage rate, rate of neonatal admission, rate of oligohydramnios, rate of amniotic fluid turbidity, acute fetal distress rate, rate of premature rupture of membranes, and macrosomia rate were compared between the two groups by chi-square tests.

There was no statistically significant difference between the two groups in age, duration since previous pregnancy, hemoglobin levels before delivery, body mass index at labor′s gestational ages, direct cesarean section rate, rate of conversion of vaginal trial to cesarean section, vaginal midwifery rate, vaginal birth rate, postpartum hemorrhage rate, rate of neonatal admission, rate of premature rupture of membranes, or incidence of macrosomia (P>0.05), although oligohydramnios rate (15.15% vs 3.15%, χ²=5.026, P=0.025), amniotic fluid turbidity rate (33.33% vs 3.15%, χ²=24.648, P<0.001), and acute fetal distress rate (12.12% vs 1.57%, χ²=5.414, P=0.020) were statistically higher in the post-term pregnancy group than in the term pregnancy group.

Super-advanced pregnant women should undergo labor induction after the 37 weeks and before the expected date to reduce the probability of poor perinatal outcomes.