Five-year follow-up of placental involution after abdominal pregnancy.

A 29-year-old woman with an abdominal pregnancy was admitted to the hospital at 29 weeks' menstrual age. At 30 weeks, laparotomy was performed, and a live fetus, wrapped in membrane remnants, was taken from the abdominal cavity. The placenta, inserted in the right hemipelvis, was left in situ. The patient's postoperative recovery was uneventful, and she was monitored periodically as follow-up. At her 5-year follow-up visit, we assessed placental involution by measuring serum beta human chorionic gonadotropin and by using color and pulsed Doppler sonography. The dynamics of the regression of placental volume yielded a bimodal curve: a phase of decrease over the first 2 months, coincident with a reduction in vascularization, followed by stability that lasted 6-8 months, and a second phase of gradual volume reduction. At 5 years, the placenta appeared as a small residual echogenic mass with no vascularity. The use of MRI in this case provided no additional information to what we found using sonography.