Sep 2007, BBC Article
Exercise Miscarriage Link

Strenuous exercise early in pregnancy could triple the risk of miscarriage, according to Danish researchers.

Miscarriage is far rarer later in pregnancy, and after the 18-week mark, the link between exercise and miscarriage disappeared.

The research found jogging, ball games and racket sports all increased the risk - as did more than seven hours of exercise a week.

Some forms of exercise did not appear to increase the risk - including swimming, one of the most popular among pregnant women.

It suggests that women who were inactive before pregnancy shouldn't embark on a new strenuous fitness regime, but should aim for a little moderate exercise every day.