Successful vaginal delivery after two caesarean sections. What are the chances?

Aim of study. To compare the outcome of attempted vaginal delivery after one and two cesarean sections. Material and methods. A prospective multicenter cohort study was carried out in the period from January 2013 to July 2019 in maternity hospitals No. 68 and No. 29 in Moscow. 334 patients were selected and divided into 2 groups: 1st — with one (1C, n=230) and 2nd — with two (2C, n=114) cesarean sections in patient’s history. The study included pregnant women with a cat-egorical disposition to deliver through vaginal delivery and refusal to deliver by caesarean section. Patients with a history of 2CS were provided with this opportunity only with a spontaneous onset of labor. Results. An attempt at vaginal delivery was more often excluded in the group with 2C than in the group with 1C (57.9% and 38%, respectively; χ2=11.88; p<0.001), and 62% of pregnant women with 1C and 42.51% — with 2C were given the attempt at vag-inal delivery. The frequency of intranatal CS in group 1 patients significantly exceeded that with a history of 2 CS (56.34% and 20.83%, respectively; χ2=18.14; p<0.001). Group 2 patients with intranatal cesarean section had a significantly higher body mass index (p<0.001) compared with that of group 1 patients. In patients with 1 CS who delivered with intranayal CS, a greater number of phenotypic markers of undifferentiated connective tissue dysplasia was revealed as compared with patients with 2 CS. Uterine rupture was diagnosed intraoperatively in only 4 patients with 1 CS, the minimum scar thickness according to the ultrasound scan was at least 2.3 mm, the maximum — 2.5 mm. The assessment of the condition of the newborn at the 1st and 5th minutes after delivery according to the Apgar scale in delivering women of all groups was higher than 8 points, including those operated on intranatal stage. This result in two groups of women with intranatal CS indicates timely diagnosis of a complicated course of labor (impaired contractile activity of the uterus, fetal distress, threatening rupture of the uterus), a change in delivery tactics in the interests of the mother or fetus. Conclusions. A history of two CSs does not preclude a successful vaginal delivery. In the presence of a history of 2CS, the chance of getting a refusal of an attempt to give birth through the vaginal birth canal is higher than with 1CS (odds ratio — OR 2.22; 95% confidence interval — CI 1.41—3.51), but when such an attempt is given — there is higher chance of success (OR 4.99; 95% CI 2.27—10.61). The success of labor is determined not by the number of CSs in history (one or two), but by the general clinical, ante-natal and intranatal characteristics of women. The success of an attempt at childbirth is determined by the full regeneration of the operated uterus, the ability of the woman’s body to ensure the effective start and maintenance of labor. The role of «non-obstet-ric» factors (body mass index for 2C, the number of markers of undifferentiated connective tissue dysplasia for 1C) is no less significant than the number of Cs in the anamnesis in the outcome of a subsequent attempt at vaginal delivery. Overweight in group 2 patients with intranatal CS necessitates correction in the pregravid period. © 2020 Global Research Online. All rights reserved.