Analysis of early and late maternal complications associated with delivery using propensity score.

Objective: To analyze early and late maternal complications associated with the mode of delivery in a birth cohort in Brazil, using the propensity score technique for analysis.

Methods: This is a prospective cohort study, using data from the Pelotas Birth Cohort, RS, 2004. A total of 4,189 women were included and a descriptive analysis of the data and subsequent calculation of the propensity and pairing score of vaginal delivery women and cesarean delivery women with similar scores (1,366 pairs). We then assessed the difference in outcome risk between the groups.

Results: Women in the cesarean group had 2.9 percentage points (pp) more risk of postpartum infection, 1.13 p.p. more risk of urinary infection, 1.10 p.p. more risk of anesthetic complications and 1.24 p.p. higher risk of headache compared to vaginal delivery, but less risk of anemia (-2.43 pp) and hemorrhoids (-1.24 p.p.). The use of propensity scores is extremely useful for reducing bias and increasing accuracy in observational studies when experimental studies cannot be performed.

Conclusion: Cesarean sections have been associated with a higher prevalence of postpartum and urinary tract infections, anesthetic complications and headache and lower prevalence of anemia and hemorrhoids, so they should be performed with clear indications and when their benefits outweigh potential risks.