The large study included data on 431 623 daughters born in Ontario obtained from the Institute for Clinical Evaluative Sciences (ICES) and linked to other databases that provided information on mother-daughter pairs.

There were 73 518 daughters whose mothers had had at least one abortion (exposed group) and 358 105 daughters whose mothers had none (unexposed group). In the exposed group, the probability of having an abortion during their teenage years was 10.1%, compared with 4.2% in the unexposed group.

As the majority of those abortions (94.5%) occurred before 15 weeks gestation, it's unlikely that the reason was a genetic or birth defect in the fetus in most cases and it may be reasonable to assume social indications.

There was also a dose-response effect: the greater number of abortions in the mother, the greater the number of abortions in her teenage daughter.

"We don't know what factors cause this association, as it was beyond the scope of our study," says Ning Liu. "Previous studies have found a higher likelihood of teen abortion if a young woman has greater social challenges, including poor school performance, separation from a biological parent, lower parental education, and receipt of income support."

"Further research is needed to determine if strategies that engage parents could reduce unprotected sex in teens, as well as to understand the major factors that contribute not only to teen pregnancy but also to the decision to have an abortion or maintain a pregnancy," says Dr. Ray. "Whatever the pregnancy outcome, the need to advocate for the health of a young woman is paramount."

Study limitations include a lack of information on the fathers, the marital status and education levels of both mother and daughter, or family dynamics and attitudes.

Source: Eurekalert