Don't delay pregnancy after miscarriage: study

NEW YORK (Reuters Health) - You don't need to delay a second pregnancy if you've had a miscarriage, Scottish researchers said Friday.

In fact, women who got pregnant within six months of their miscarriage were more likely to go on to have a live birth than those who waited longer, the researchers' report shows.

"Women are often advised to delay the second pregnancy," Dr. Sohinee Bhattacharya, who worked on the study, told Reuters Health.

Since 2005, the World Health Organization (WHO) has recommended that women wait at least half a year before they try again. According to Bhattacharya, of Aberdeen Maternity Hospital, those guidelines are widely used, but based on very little evidence.

"The sound advice to women is that there is no physical reason why you would delay your second pregnancy," she said.

In developed countries, many women have their first child later in life, which ups the chances of miscarrying. Almost a third of 40-year-olds miscarry, for example, according to the researchers, whose findings are published in the journal BMJ.

So Bhattacharya's advice is to try again as soon as possible.

"But," she added, "there is no point in saying 'Yes, go for it now' if the woman is completely drained emotionally or physically."

Other doctors say it's too early to change current practice.

"We would need some additional data to really firmly direct patients," obstetrician Dr. Alison G. Cahill of Washington University in St. Louis told Reuters Health.

"What I tell my patients is that there is some available data and that from that data the recommendation from the WHO is to wait 6 months," she said. "But when we take a step back, most women go on to have a successful pregnancy."

The Scottish researchers examined hospital data for more than 30,000 women who had a miscarriage in their first recorded pregnancy.

Of those who got pregnant within six months of the miscarriage, 85 percent gave birth to a live baby and 10 percent miscarried again.

If more time went by, however, fewer than 80 percent of the women had live births and more than 12 percent miscarried.

Those findings held even after accounting for the women's age and socioeconomic status, although adjusting for smoking tended to reduce the differences.

Bhattacharya stressed the results might not hold in developing countries, where women tend to be much younger when they have kids.

What makes the data difficult to interpret, said Cahill, is that there is no way of telling exactly how soon after their miscarriages women started trying to get pregnant again. The researchers only know when they became pregnant.

The results also say nothing about the effects of the 2005 WHO guidelines because the hospital records examined were from 1981 to 2000.

If most of the women were trying to get pregnant again right away, those who succeeded early on might have had a healthier reproductive system. That, in turn, might boost their chances of having a live birth.

Whatever the explanation, said Cahill, "the most likely outcome is a successful pregnancy."

SOURCE: link.reuters.com/caj73n BMJ, online August 6, 2010.