In the wake of reports that two more women had died after taking abortion pill, the US doctors started doubting the safety of abortion pills.

Mifeprex, also known as RU-486, induces a miscarriage, in association with another drug, misoprostol that generally occurs within two weeks. To some women, this process seems more natural than surgery, and the expulsion of the fetus often takes place at home, which some also prefer. However, doctors prefer surgery to pill abortion as many of them consider the method rather "lousy’’.

The number of women who have died in the United States after taking Mifeprex has now reached six, according to reports received by the Food and Drug Administration; another has died in Canada.

Mifeprex has been used in more than 560,000 abortions in the US, so the reported risk of death is a bit more than one in 100,000. Some deaths may have gone unreported, meaning the real risk may be even higher.

By contrast, the reported risk of death associated with surgical abortion is one in a million, according to studies — one-tenth as high.

Pill-based abortions are also 5 to 10 times as likely to fail as surgical ones, and those that do fail require a follow-up surgical procedure in women whose pregnancies by then may have advanced significantly.

Also, women who undergo medical abortions suffer an increase in complications, some doctors say. A 1999 study of 377 women found that those who took the pills suffered significantly higher levels of pain, nausea, vomiting and worrisome bleeding than those who underwent surgical abortions.

Probing the deaths, the F.D.A. officials said that there was neither a definitive link between the infections and RU-486 nor any concrete evidence that the drug increased the risk of infection beyond that found in women who underwent surgical abortions, suffered natural miscarriages or gave birth.