Is induced abortion a contributing factor to tubal infertility in Mexico? Evidence from a case-control study.

OBJECTIVE

To determine the contribution of induced abortion to tubal infertility in Mexico.

DESIGN

Population- and hospital-based case-control study.

SETTING

Tertiary hospitals in Mexico City.

SAMPLE: Women between 20 and 40 years with infertility and controls of the same age: 251 cases, 502 hospital controls, 502 neighbourhood controls.

METHODS

A case-control study was conducted in four tertiary hospitals in Mexico City with 251 cases and 1004 controls (two hospital and two neighbourhood controls per case, matched by age [+/-2 years]). Cases were infertile women, aged 20-40, with tubal occlusion confirmed by laparoscopy. Controls were fertile women, who had carried a pregnancy to term within the last two years. Participants completed a previously validated questionnaire asking about reproductive history and induced abortion.

RESULTS

Our study did not show an association between induced abortion and tubal infertility among women that did not relate both events (cases vs hospital controls: OR = 1.57, 95% CI: 0.29-8.65; cases vs neighbourhood controls: OR = 0.82, 95% CI: 0.07-8.99) using conditional logistic models adjusting by marital status, number of pregnancies, age at first sexual intercourse and history of pelvic inflammatory disease. In contrast, early age at sexual debut and history of pelvic inflammatory disease significantly increased the risk of tubal infertility.

CONCLUSIONS

In Mexico, the lack of association between induced abortion and tubal damage causing infertility observed in this population might be explained by a shift toward "safer" abortion practices.