Abdominal Pregnancy with Viable Fetus: A Diagnostic Pitfall

Abdominal pregnancy, described as the implantation of gestational sac in the abdominal peritoneum, accounts for fewer than 1% of ectopic pregnancies, a misinterpretation in ultrasound for abdominal pregnancy with intrauterine pregnancy often found in advanced gestational age that correspond with high rates of morbidity and mortality for the mother and fetus. Here, we present a case of abdominal pregnancy with viable fetus. A 33-year-old woman, G3P2, 30 weeks of gestation referred to our outpatient clinic for ultrasound examination due to fetal growth restriction. She only had one ultrasound examination in this pregnancy and never had any complaint of abdominal pain or any vaginal bleeding. At first examination, it was difficult to measure fundal height but her fetal heart rate showed normal rhythm. On first ultrasound examination, we suspected with complete placenta previa but could not ensure fetal lie and presentation. The conservative management was done for this patient to do the surveillance monitoring, but the next ultrasound showed that placenta located in posterior part of uterus, with empty uterine cavity and corresponding with intraoperative findings. The patient underwent cesarean section; placenta was left in situ and planned to do evaluation 3 months after delivery. Despite the good outcome, abdominal pregnancy diagnostic accuracy was only 50% that poses diagnostic challenges. It is important to be aware that abdominal pregnancy could cause a fatal adverse outcome. Early ultrasound screening and diagnosis are needed to plan for better management in these cases.