Abortions in relation to age, coital frequency, and fecundity.

Abortion rates show variations by age in the United States. This article addresses the question of age variations in abortions. Since the probability of pregnancy is increased in direct proportion to increased coital frequency, age and coitus-specific abortion rates are calculated. Since the probability of pregnancy is related to fecundity, age and fecundity abortion rates are also calculated. When combining coital frequency and fecundity with the age-specific abortion rates, the variation by age disappears for all women except teen-agers.