A Bronx woman has filed a lawsuit against St. Luke’s-Roosevelt Hospital, claiming that doctors misdiagnosed a problematic pregnancy and wrongfully advised her to have an abortion.

Mbayme Ndoye, a 29-year-old Senegalese immigrant, sought medical attention at Roosevelt Hospital on October 15 after experiencing abdominal cramps. After performing a sonogram, doctors told Ms. Ndoye that she was pregnant and that the pregnancy was ectopic, a complication in which the fetus develops outside the womb.

Ectopic pregnancies cannot result in successful births, and they pose a serious health risk to mothers.

According to Ms. Ndoye’s lawyer, Brian Brown, Ms. Ndoye and her common-law husband, Papa Tourre, agreed to terminate the pregnancy when medical staff explained the condition. Ms. Ndoye was given methotrexate, a cancer drug that is also used to terminate pregnancies.

The drug is administered in four doses, and when Ms. Ndoye returned the next day for follow-up treatment, doctors told her they made a mistake, and that her pregnancy had been healthy. Two days later, she sought treatment from a private physician, but the doctor was not able to reverse the effects of the medication. She subsequently had surgery to remove the developing fetus.

“It’s a pretty horrific experience,” Mr. Brown, a partner at the firm Zaremba, Brownell & Brown, said. “There’s a sense of shame, that maybe she’s responsible,” he said. A spokeswoman for the hospital declined to comment, pending the litigation.

Roosevelt, which merged with St. Luke’s Hospital in 1979, is part of Continuum Health Partners, a network that also includes Beth Israel Medical Center, New York Eye and Ear Infirmary, and Long Island College Hospital. Last year, Roosevelt doctors delivered 5,750 babies, and the hospital expects nearly 6,000 deliveries this year. A 2006 report by the city’s public advocate found that the hospital’s rate of cesarean sections in 2004 was 26.7%.

Mr. Brown said that several days after the incident, a woman who identified herself as a nurse supervisor at the hospital called Ms. Ndoye and said it was a “sad story.” But the hospital has not formally apologized, he said. Ms. Ndoye filed a lawsuit in January but decided this week to publicize details of the alleged medical error, he said.

Since the incident, Ms. Ndoye, who has a 3-year-old son with Mr. Tourre, has been receiving counseling, he said. “She aborted her own healthy child, which she would not have done. This is a pretty traumatic experience,” Mr. Brown said.

Ms. Ndoye is seeking unspecified financial compensation, he said.