Sexually transmitted diseases as major causes of ectopic pregnancy: results from a large case-control study in France.

OBJECTIVE

To evaluate the current impact of sexually transmitted diseases (STDs) and their consequences on the occurrence of ectopic pregnancy (EP).

DESIGN

Case-control study.

SETTING

Fifteen maternity hospitals in the Rhône-Alpes region, France.

SUBJECTS

Six hundred twenty-four women with EP diagnosed from October 1988 to December 1991 and 1,247 controls who delivered liveborn children during the same period.

MAIN OUTCOME MEASURES

Information on risk factors included behavioral, clinical, and serological indicators of STDs and other known risk factors of EP.

RESULTS

Logistic regression identified several indicators of STDs as strong and independent risk factors for EP: previously treated STD without history of salpingitis; history of probably pelvic inflammatory disease (PID) and, especially, history of confirmed PID; previous STDs of the sexual partner; and Chlamydia trachomatis seropositivity. The adjusted attributable fractions of EP for previous symptomatic STDs, symptomatic STDs of the sexual partner, and C. trachomatis seropositivity were 20%, 3.5%, and 25.2%, respectively, giving a total of 43% of EP cases attributable to infectious factors.

CONCLUSIONS

Our findings and previous epidemiological and biological evidence suggest that STD is a major cause of EP. The evidence is particularly strong in the case of C. trachomatis infection. An effective way of dramatically reducing the EP rate would be to prevent STD through education programs sensitizing young women to the complications of STD and public health measures promoting the use of protective methods such as condoms.