Risks associated with subsequent pregnancy after one caesarean section: A prospective cohort study in a Nigerian obstetric population
Context: Aversion for cesarean delivery is common in our practice and risks associated with caesarean section may contribute to this phenomenon.
Objective: The objective of this study was to estimate the risks associated with subsequent pregnancies in women with one previous cesarean section in a low resource setting.
Setting and Design: A prospective cohort study carried out at two major tertiary maternity centers in Enugu.
Materials and Methods: Maternal and perinatal outcomes were compared between women with one previous caesarean and women who had only previous vaginal deliveries.
Statistical Analysis Used: Analysis was performed with SPSS statistical software version 17.0 for windows (IBM Incorporated, Armonk, NY, USA) using descriptive and inferential statistics at 95% of the confidence level confidence.
Results: A total of 870 women were studied. These were divided into 435 cases and 435 controls. The absolute risk of cesarean section in a subsequent pregnancy in women with one previous cesarean was 75.8% (95% confidence interval [CI]: 72.0, 80.0). Cesarean section was significantly commoner in women with one previous cesarean compared
with those who had previous vaginal delivery (Relative risk [RR] =3.78; 95% CI: 1.8, 6.2). Placenta praevia (RR = 5.0; 95% CI: 2.6, 7.2.), labor dystocia (RR = 6.4, 95% CI: 3.2, 11.2) intrapartum hemorrhage (RR = 5.0, 95% CI: 2.1, 9.3) primary postpartum hemorrhage (RR = 5.0, 95% CI: 1.5, 4.3.), blood transfusion (RR = 6.0, 95% CI: 3.4, 10.6) and Newborn special care admission (RR = 2.5; 95% CI: 1.1, 4.9) were significantly more common in women with one previous cesarean compared with those with previous vaginal deliveries. The absolute risk of failed trial of vaginal birth after a cesarean was 45% (95% CI: 38.5, 51.5).
Conclusion: Women who have one previous C.section face a markedly increased risk of repeat caesarean sections and feto.maternal complications in subsequent pregnancies. There is a need for doctors in Nigeria to be mindful of these risks while offering primary cesarean section in this low resource setting.
Key words: Absolute risks, pregnancy after caesarean, primary cesarean section