Risk of preterm birth and low birthweight following consecutive surgical and medical abortions

Purpose: To examine the effect of consecutive surgical compared to medical uterine evacuations on spontaneous preterm birth (SPTB) and low birthweight (LBW) rates in the immediate subsequent delivery. Methods: Retrospective study, conducted at a teaching hospital on data from January 2000 to March 2016. First study group consisted of all women who had ≥2 consecutive medical evacuations (ME-Group); second study group consisted of women who had ≥2 consecutive surgical evacuations (SE-Group). Both had a subsequent singleton delivery. Control group consisted of women without previous evacuations (unexposed group). The groups were matched for year of birth and ethnicity. The primary outcome was a composite that included SPTB (<37 weeks) and LBW (<2500 g). Results: All 70 women found eligible in the ME-Group during the study period were included. SE-Group and the unexposed group consisted of 140 and 210 women, respectively. Primary outcome occurred in 4.3, 11.4, and 2.4% in the ME-Group, SE-Group, and the unexposed group, respectively (p = 0.002). After adjusting for variables that differed between the groups in univariate analysis, the primary outcome incidence was significantly higher among the SE-Group compared to the unexposed group (adjusted OR 6.8, 95% CI 1.7–26.3, p = 0.006). The difference was insignificant between the ME-Group and the unexposed group (adjusted p = 0.31). In the SE-Group, 7.1% women required fertility treatments to achieve a desired pregnancy compared to 1.4% in the ME-Group (p = 0.04). Conclusion: Two or more consecutive surgical evacuations were associated with an increased risk of both SPTB and LBW compared to unexposed group.