When doctors examined the woman further and discovered the abdominal pregnancy, they quickly operated on the woman's abdomen and found her live fetus floating in her abdominal cavity, without its nourishing amniotic sac. The healthy baby girl was delivered and sent home with her 22-year-old mother in good condition, researchers in Tanzania said.
Abdominal pregnancies are rare, and when they do happen, they can go unnoticed even if ultrasounds are used, because the pregnancy can appear normal in an ultrasound examination, the researchers wrote in the report, published Feb. 25 in the journal BioMed Central. An abdominal pregnancy that goes unnoticed can threaten the mother's life and cause massive bleeding.
"I've seen maybe four or five abdominal pregnancies over the course of 25 years," said Dr. Jill Rabin, chief of ambulatory care, obstetrics and gynecology at Long Island Jewish Medical Center in New Hyde Park, N.Y., who wasn't involved with the case.
"Many times, these pregnancies are not diagnosed until the labor," Rabin said. "The woman is going through labor, the cervix is dilated and you are wondering, 'Why is the patient having contractions and nothing is happening?'"
Abdominal pregnancy is a rare form of ectopic pregnancy, occurring in about 1 out of every 10,000 pregnancies, according to some estimates. In an abdominal pregnancy, an embryo usually first implants in one of the fallopian tubes (instead of the uterus), and then moves backward within the body, toward the ovaries. From there, it implants for the second time — this time, in the abdomen.
Diagnosing an abdominal pregnancy is difficult, Rabin said. "It's very rare, but you have to keep it in your mind when examining a pregnant woman who has abdominal pain."