A 37-year-old woman went to the emergency department after 10 days of abdominal pain, and she eventually left a tertiary care hospital with her baby -- which had grown in her abdomen.
"Ultrasonography revealed a thickened endometrium, empty uterus, and abdominal pregnancy at 23 weeks' gestation," Guillaume Gorincour, MD, PhD, of IMADIS Téléradiologie in Lyon, France, and Malik Boukerrou, MD, PhD, of Centre Hospitalier Universitaire Sud Réunion in Saint-Denis, France, reported in the " in the New England Journal of Medicine.
An abdominal MRI confirmed a non-gravid uterus and a normally formed intra-abdominal fetus. The MRI also showed "a placenta that attached to the peritoneum above the sacral promontory," wrote Gorincour and Boukerrou.
Clinicians diagnosed the patient with an abdominal pregnancy, an ultra-rare form of ectopic pregnancy that occurs most often in the fallopian tubes.
Gorincour told in an email that abdominal ectopic pregnancy occurs in 1 in 10,000 to 25,000 pregnancies, and accounts for less than 1% of all ectopic pregnancies.
"An abdominal pregnancy is the only type of ectopic pregnancy that can go beyond 20 weeks gestation," Gorincour said, noting that implantation sites can include "the peritoneum of the pelvic and abdominal cavity, or even abdominal organs such as the spleen, intestine, liver and blood vessels."
He added that the maternal mortality rate with abdominal pregnancy is more than 7 times higher than other forms of ectopic pregnancy due to the risk of massive placental hemorrhage.
David Hackney, MD, a maternal-fetal medicine specialist at Case Western Reserve University in Cleveland, told that the vast majority of abdominal ectopic pregnancies are not survivable. He said this situation is "the rarest of the rare" and that he's never personally seen one.
Gorincour and Boukerrou reported that owing to the high risk of maternal hemorrhage and fetal death, the patient was transferred to a tertiary care hospital. After she reached 29 weeks' gestation, doctors performed "a laparotomy with infant delivery, placental arterial embolization, and partial removal of the placenta." Nearly 2 weeks later, the placenta was surgically removed.
The patient remained in the hospital for nearly a month and her infant was in the neonatal intensive care unit for 2 months.
Hackney commented that in these rare abdominal ectopic pregnancies, "it's actually often not safe to take the placenta out, especially if it's wrapped among some of the blood vessels or the bowel." In those cases, the placenta is left to degrade inside the abdomen, which takes about 2 weeks. Hackney said that also carries risk.
He stressed that this patient's unusual case does not mean that abdominal ectopic pregnancies are safe enough to continue. However, this patient had late presentation of symptoms and hadn't engaged with the healthcare system.
The mother in this case was from a remote island and had delivered two babies vaginally before. She had also miscarried once. She didn't have sexually transmitted infections or previous surgery, and she declined contraception upon discharge. Ultimately, she was lost to follow-up, the researchers said.
"The standard recommendation, if you find these earlier, is it's generally considered too dangerous to advance," Hackney said. "This is a lucky patient who could have, you know, died. It looks like things turned out well, but this was a very close call."
Primary Source
New England Journal of Medicine
Gorincour G, Boukerrou M "Abdominal ectopic pregnancy" N Engl J Med 2023; DOI: 10.1056/NEJMicm2120220.