Fecundability and husband's age.

The effect of husband's age on the probability of conception is evaluated from World Fertility Survey data in five developing countries: the Ivory Coast, Ghana Kenya, the Sudan, and Syria. Proportional hazards models, which include wife's age, husband's age, marriage duration, union type, and post-partum exposure as covariates, are used to describe the monthly conception rate for second and higher-order birth intervals in which no contraception was used. With the exception of Syria, the resulting models indicate that the effects of male age are generally small in relation to the influences of marital duration and the age of the woman.