Miscarriage ups risk in next pregnancy

Pregnant women who suffer a miscarriage in the second-trimester are at high risk during a subsequent pregnancy of a spontaneous preterm birth and repeat second-trimester miscarriage, a study indicates.

Dr. Michal A. Elovitz and associates studied three groups of women: 30 women who had a spontaneous second-trimester miscarriage; 76 women with a spontaneous preterm birth; and 76 women with full-term deliveries. All of the women had a subsequent pregnancy beyond 14 weeks' gestation.

They frequency of subsequent second-trimester loss was highest (27 percent) in women who suffered a second-trimester loss in the first pregnancy, they report.

The frequencies of subsequent second-trimester loss were three percent and one percent in the spontaneous preterm birth, and full-term delivery groups, respectively.

Corresponding frequencies of subsequent spontaneous preterm birth were 33 percent, 39,5 percent and nine percent for the three groups, respectively.

"Of great clinical concern," the team notes, "is that women with prior second-trimester pregnancy loss have a high frequency of very early preterm birth."

In this group, spontaneous preterm birth at less than 28 weeks was 10 percent, versus 1,3 percent in the other two groups.

The researchers suggest that the biologic mechanism for second-trimester losses may be similar to that of spontaneous preterm birth, possibly related to "cervical ripening" as a primary event. If so, "women with second-trimester loss would be candidates for therapy that reduces subsequent preterm birth," they suggest.