[The outcome of trial of labor after cesarean section]

Objective: To explore the outcome of trial of labor after cesarean section(TOLAC). Methods: Totally 614 TOLAC were conducted in the First Affiliated Hospital of Kunming Medical University from July 2013 to June 2016. Among them, 586 cases of singleton pregnancy with one prior cesarean section(gestational age≥28 weeks)were studied retrospectively. The maternal and neonatal outcomes among the vaginal birth after cesarean(VBAC)group(481 cases), failed TOLAC group(105 cases)and the elective repeat cesarean section(ERCS)group(1 145 cases)were compared. Multiple logistic regression was used to determine the risk factors of admission to neonatal intensive care unit(NICU). Results: (1)The TOLAC rate was 29.62%(614/2 073)from July 2013 to June 2016, and the VBAC rate was 82.6%(507/614). The cesarean section rate was reduced by VBAC by 3.147%(507/16 112).(2)The comparison of adverse maternal outcomes: in the VBAC group, the postpartum hemorrhage volume was(431±299)ml, the rate of postpartum fever was 6.4%(31/481), the birth weight of the neonates was(3 085± 561)g, and the rate of large for gestational age was 2.9%(14/481). All were significantly lower than those in the failed TOLAC group and the ERCS group(P<0.05). There was no significant difference in other adverse maternal outcomes[the uterine rupture rate(0.2% ,1/481), the bladder injury rate(0), the proportion of postpartum hemorrhage volume≥1 500 ml(1.0%, 5/481), the blood transfusion rate(3.7%, 18/481)]and adverse perinatal outcomes[the rate of neonatal 5-minute Apgar score<7(0.4%, 21/481), the rate of umbilical arterial pH<7.0(0.6% , 3/481), the rate of the NICU admission and the perinatal mortality rate(12.3%, 59/481)]among the 3 groups(P>0.05). Multiple logistic regression showed no association between VBAC and admission to the NICU(OR=0.84, 95%CI: 0.58-1.21). The isolated risk factors for admission to the NICU were preterm birth(OR=16.71, 95% CI: 11.44-24.40), hypertensive disorder complicating pregnamcy(OR=3.89, 95% CI: 2.39-6.35), meconium stained amniotic fluid(OR=2.48, 95% CI: 1.62-3.80), small for gestational age(OR=2.00, 95% CI: 1.19-3.36)and diabetes mellitus(OR=1.69, 95% CI: 1.14-2.50). Conclusions: VBAC reduces cesarean section rate, with good outcomes in both mother and neonate. It is a safe and feasible way of labor in women with only one cesarean section history.