Induced abortion and ectopic pregnancy: A systematic review and meta-analysis

Existing evidence of the relationship between induced abortion and ectopic pregnancy has not been assessed rigorously. This systematic review provides a comprehensive evaluation to examine whether induced abortion (IA) can increase the rate of ectopic pregnancy (EP).

We searched PubMed, EMBASE, Web of Science, Cochrane, CNKI, WanFang, and Sinomed databases since their inception until February 2023. Eligibility criteria included case-control studies and cohort studies that analyzed induced abortion associated with ectopic pregnancy. Data analyses were conducted by using R-studio Version 1.1.383 software.

A total of 33 case-control studies and 7 cohort studies involving 132,926 participants were included. In case-control studies, there was a significant association between induced abortion and ectopic pregnancy by using single-factor analysis data (OR = 2.32, 95% CI = 1.81-2.98). Subgroup analysis by region suggested no statistical significance in the Americas (OR = 1.15, 95% CI = 0.92-1.43) and Eastern Mediterranean (OR = 3.64, 95% CI = 0.88-15.18). The relationship was significant by using multiple regression analysis data (OR = 1.97, 95% CI = 1.38-2.80). In cohort studies, statistical significance was found (OR = 1.42, 95% CI = 1.001-2.018) after omitting one study in sensitivity analysis. The combined results of the two types of studies suggested that induced abortion would increase the risk of ectopic pregnancy to some degree, but the conclusion needs to be considered with caution.

This study indicated that IA could increase the risk of EP to some degree and the times of IA had a negative impact on the risk. Safe abortion and avoiding repeat abortion due to unintended pregnancy could protect women's fertility.