Doctors at a hospital in Hanoi surgically removed a dead fetus from a woman last week, which had developed inside her liver, newswire VnExpress reported.
P.H.H, 25, of Hanoi was hospitalized on the evening of June 27 with low blood pressure and dizziness.
The woman said she was 21 days late and guessed she was pregnant.
The doctors performed a two-hour surgery and removed a dead fetus from the back side of her liver.
The woman has had fetuses develop outside her uterus twice before.
Dr. Nguyen Van Ha of the National Hospital of Obstetrics and Gynecology said the patient is now in stable condition and should be discharged from hospital soon.
She may become pregnant again but must be closely monitored, Ha said.
According to the doctor, in some cases, an embryo falls out of the fallopian tube and then implants itself anywhere in the abdominal area.
In extremely rare cases, such as this one, the embryo attaches itself to the liver, a very rich source of blood.
In the world, there have only been around 20 documented cases of fetuses developing in this way, he said.
The baby is protected because it is within the placenta - but it does not have the usual protection of the womb - and is grave danger elsewhere inside the abdominal cavity.