Factors related to infertility in the United States, 1965-1976.

Although the overall rate of infertility among American women of reproductive age remained fairly constant between 1965 and 1976, the percentage of young black women who were infertile increased very sharply. In 1976, 18% of black women of reproductive age were infertile, whereas only 9% of white women of the same age were infertile. With use of national data bases, the relationships between sexual activity, complications of pregnancy, sexually transmitted diseases, pelvic inflammatory disease, use of contraception, and infertility were examined. Available evidence shows a strong association between sexually transmitted diseases, pelvic inflammatory disease, and infertility trends. Our projections indicate that sexually transmitted diseases operating through pelvic infections account for much of the race differential in infertility as well as for one-half to one-third of the increase. In 1976 5-8% of 20-29-year-old black women were estimated to suffer infertility attributable to sexually transmitted diseases. Among white women the estimated incidence of infertility caused by sexually transmitted diseases was 0.7-1%.