The use of mifepristone (RU-486) to induce early abortion does not appear to adversely affect subsequent pregnancies, according to a study involving more than 14,600 Chinese women.

In the American Journal of Epidemiology, Dr. Ershen Gao of the Shanghai Institute of Planned Parenthood Research, and colleagues note that although the effect of surgical first-trimester abortion on subsequent pregnancies is well documented, this is not the case with mifepristone.

To investigate, the researchers followed three groups of women through pregnancy and childbirth. The groups consisted of 4925 women with no history of induced abortion, 4931 with one previous mifepristone-induced abortion and 4800 with one previous surgical abortion.

Compared with women with no abortion history, women in the mifepristone group were 23 percent less likely to have a preterm delivery, and the average birth weight of their infants was slightly higher.

However, the likelihood of low birth weight and the average length of pregnancies were similar in these two groups.

Also, there were no significant differences in these factors between mothers who had had a mifepristone or a surgical abortion.

The researchers therefore conclude that one mifepristone-induced abortion “has no adverse effects on the outcome of a subsequent pregnancy.”

SOURCE: American Journal of Epidemiology, July 15, 2004.