A Comparative Study of the Spontaneous Labor Rate in Scheduled Elective Cesarean Section at 38 Weeks versus 39 Weeks of Gestation in Parturient with Previous Cesarean Section
Natavadee Todumrong MD*, Charintip Somprasit MD*, Chamnan Tanprasertkul MD*, Kornkarn Bhamarapravatana PhD**, Komsun Suwannarurk MD*
Affiliation : * Department of Obstetrics and Gynecology, Faculty of Medicine, Thammasat University, Pathumthani, Thailand ** Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
Objective : To assess the effect of the different scheduled gestational age for a repeat elective cesarean section (CS) on
emergency cesarean section rate and adverse pregnancy outcomes in pregnant women with history of previous CS.
Material and Method: A prospective cohort study of singleton pregnant women who had a history of CS and were scheduled
for a repeat elective CS to be performed. The cases were divided into two groups of which the elective CS was appointed at
38 or 39 weeks of gestation as study and control groups, respectively. Emergency cesarean section rate, maternal and
neonatal complications were defined as main outcomes.
Results : Of 415 scheduled elective repeat cesarean deliveries performed at 38 weeks of gestation or later, 209 were scheduled
between 38 0/7 and 38 6/7 weeks (study group), and 206 were scheduled between 39 0/7 and 39 6/7 weeks (control group).
Most of the cases had one previous cesarean delivery. The emergency CS rate before schedule in the study group was
significantly less than in the control group (15.3% vs. 51%, p<0.001). Spontaneous labor pain was a major factor to have
unplanned delivery. The maternal intra-operative complications were significantly increased in women who had emergency
cesarean before schedule compared to elective CS on scheduled in 38 weeks group (25% vs. 12.9%, p<0.001) and 39 weeks
group (31.4% vs. 14%, p<0.001). The major intra-operative complication was uterine atony. There were no statistically
significant differences in maternal post-operative and neonatal complications in scheduled elective CS in 38 and 39-week
group. Transient tachypnea of the newborn (TTNB) was higher in elective CS at 38 week compared to emergency CS.
Conclusion : The emergency CS rate in 39 weeks gestation group was significantly higher than 38 weeks group. The
incidence of adverse maternal intra-operative complications was statistically difference with emergency CS when compared
to elective CS in case and control groups. Recommendation of elective repeated CS at GA39 weeks may be suitable only under
some circumstances. The number of prior CS is one of factors that should be considered.
Keywords : Repeated cesarean section, Previous cesarean section, Spontaneous labor, Maternal and neonatal outcome
