The relationship between prior
condom use and
tubal pregnancy was assessed in a population-based case-control study at Group Health Cooperative of Puget Sound during 1981-86. We interviewed 227 women with a
tubal pregnancy who had no clinical indication of
infertility and no history of sterilization and 674 similarly defined controls who were matched to the cases on age and county of residence. A history of
condom use for more than one year was associated with a decreased risk of subsequent
tubal pregnancy (RR = 0.74, 95% CI = 0.44, 1.26) adjusted for the effects of age, current use of
contraceptive methods, educational level, and age at first intercourse. The effect was more pronounced when
condoms had been used during five-year periods with more than one partner (RR = 0.38, 95% CI = 0.15, 1.0) than during five-year periods with one partner (RR = 0.89, 95% CI = 0.45, 1.76).
Condom use for less than one year was unrelated to risk of
ectopic pregnancy. Since the use of
condoms offers protection against
sexually transmitted diseases, one or more of which are likely to be causally related to
tubal pregnancy, the observed negative association plausibly represents a protective influence of long-term
condom use on the occurrence of
tubal pregnancy.