Primary infertility and oral contraceptive steroid use

Abstract

To determine the association between combined monophasic oral contraceptive (OC) use and primary infertility. Case-control. Women serving as controls of the Cancer and Steroid Hormone Study. Women were 19 to 40 years of age at first conception or infertility diagnosis. Based on 24 consecutive months of unprotected intercourse without a recognized conception, 419 nulligravid women had primary infertility; controls were 2,120 fertile women. A calendar of each woman’s reproductive history was used to determine fertility status and contraceptive use before infertility diagnosis or first conception. Primary infertility. Combined monophasic OC use was associated with a lower frequency of primary infertility, particularly among younger (age 20 years) compared with older women (age 30 years) after adjusting for barrier method use and education. A similar association was found for duration of OC use. When adjusted for age at first conception or infertility and barrier method, both higher (> 50 μ g) and lower (≤ 550 μ g) estrogen dose use were associated with decreased risk of primary infertility. Combined monophasic OC use was associated with a lower frequency of primary infertility.