Cesarean Section and Its Impact on Uterine Artery Resistance and the Risk of Pre-eclampsia in Subsequent Pregnancies

Background: the purpose of the current study was to compare the color doppler findings of uterine arteries and perinatal outcomes in pregnant women with and without previous cesarean section (c/s). methods: this cohort study enrolled 308 pregnant women aged 20-35 without underlying diseases, with at least one previous pregnancy and childbirth. the participants were divided into two groups: 154 women without c/s and 154 women with c/s. baseline data were collected, followed by uterine artery doppler scans. then, the perinatal outcomes, including pre-eclampsia, intrauterine growth restriction (iugr), premature delivery, and birth weight were evaluated. results: the average age of patients in the c/s group was 30.46±3.81, which was significantly higher than the non-c/s group (28.86±4.64). it was found that uterine artery resistance was higher in women with c/s history (1.11±0.44, p<0.001) compared to those without (1.00±0.37, p<0.001). pre-eclampsia incidence was also higher in c/s group (16.1%, p=0.042) compared to non-c/s group (9.1%, p=0.042). the incidence of preterm birth in the c/s group (p=0.209), the incidence of iugr (p= 0.791), and the average birth weight (p=0.291) in the two groups did not differ significantly. the average gestational age in the c/s group was 37.54±1.4, and in the non-c/s group was 38.01±1.99 weeks. the results were not affected by potential confounders such as age, the time interval between pregnancies, and also body mass index. conclusion: previous cesarean section can significantly increase the uterine artery resistance in subsequent pregnancy.