Reality Check: There is no evidence that fertility is greater after a missed pregnancy

Seattle Post-Intelligencer, October 26, 2008

THE BELIEF:

A woman is more fertile after a miscarriage.

THE FACTS:

This popular claim, floated in many online fertility forums, does not appear to hold up.

One explanation for the claim is that after a miscarriage, levels of hormones, such as progesterone, which facilitates gestation, are still elevated, increasing fertility. But no studies have shown that to be the case.

Unsuccessful pregnancies, sometimes called missed pregnancies, are common, occurring in 30 percent to 50 percent of conceptions. (Some occur so early that the woman may not notice.) Many are caused by chance chromosomal abnormalities in the embryo that are unlikely to affect the next pregnancy. Others result from progesterone deficiencies; according to a 2007 review of other studies, the effectiveness of progesterone supplements in preventing future problems is somewhat unclear.

But the science is encouraging. According to a report by the Royal College of Obstetricians and Gynecologists, the probability of a second miscarriage is just 2.25 percent, and the odds of a third are less than 1 percent. Another study in The New England Journal of Medicine followed a large sample of healthy women seeking to conceive and found that of those who miscarried, 95 percent became pregnant within two years.

THE BOTTOM LINE:

There is no evidence that fertility is greater after a missed pregnancy.

SOURCE: The Seattle Post-Intelligencer