Interstitial Pregnancy Resulting in a Viable Infant Coexistent with Massive Perivillous Fibrin Deposition: A Case Report and Literature Review

Abstract

Objective The objective of this report is to describe a rare case of interstitial pregnancy ultimately resulting in a viable infant coexistent with massive perivillous fibrin deposition (MPFD). Study Design This study is a case report and literature review. Results A 35-year-old female patient underwent cesarean section at 32 weeks of gestation due to fetal growth restriction (FGR) and breech presentation. During the operation, a diagnosis of interstitial pregnancy was established. There was no evidence of placental separation. We decided to complete surgery without removal of the placenta and waited until the placenta delivered spontaneously. The conservative management was successful, and the patient was discharged on postoperative day 13. The pathologic examination showed MPFD. Conclusion If interstitial pregnancies are not diagnosed at an early gestational age, it can result in a viable fetus, but such pregnancies may be associated with FGR or placenta accreta.

An evident asymmetrical uterus during cesarean delivery

“…Uterine rupture usually occurs in the first trimester; thus, there have been few reports on full‐term interstitial pregnancy resulting in a live birth 1, 2. Although it is essential to check the implantation site during early pregnancy, the abnormal position of the gestational sac had not been noticed during early pregnancy by the previous doctor, and we could not detect an interstitial pregnancy after the midtrimester.…”

“…Intraoperative observation revealed an asymmetrical uterus. Our previous experience with a similar case suggested an interstitial pregnancy complicated by placenta accreta 1. The undelivered placenta was observed on the left side of the uterine fundus (Figure 1A,B); thus, a supracervical hysterectomy was performed.…”

“…Interstitial pregnancies account for 3% of all tubal pregnancies 1. Uterine rupture usually occurs in the first trimester; thus, there have been few reports on full‐term interstitial pregnancy resulting in a live birth 1, 2.…”

Three‐Dimensional Sonography in the Differential Diagnosis of Interstitial, Angular, and Intrauterine Pregnancies in a Septate Uterus

“…Interstitial pregnancy refers to implantation of the embryo in the intramural portion of the fallopian tube covered by the myometrium 6 . It is a true form of ectopic pregnancy, with a reported mortality rate of 2% to 2.5% 7 .…”

“…Interstitial pregnancy refers to implantation of the embryo in the intramural portion of the fallopian tube covered by the myometrium. 6 It is a true form of ectopic pregnancy, with a reported mortality rate of 2% to 2.5%. 7 In the previous literature, authors have proposed the following diagnostic criteria based on 2D sonography: (1) an empty uterine cavity; (2) a chorionic sac separate and at least 1 cm from the lateral edge of the uterine cavity; and (3) a thin (<5 mm) myometrial layer surrounding the gestational sac.…”