Cesarean Scar Ectopic Pregnancy - A Case Presentation

Introduction
Implantation in the scar of a previous Cesarean is thought to be the rarest of ectopic pregnancies.¹ With the increasing numbers of Cesareans performed, scar implantation may become more frequent as well. We present an illustrative case.

Case Presentation
Our patient is a 32 year old P 1001 who was referred for evaluation of a continued first trimester vaginal bleeding. She had previously undergone Cesarean delivery for dystocia. Subsequently, she developed an incisional mass. Surgical excision revealed endometriosis.

TVS and TAS were both performed. Ultrasound revealed an enlarged uterus with blood within the uterine cavity. A gestational sac was noted implanted in the anterior lower uterine segment in the region of the previous uterine incision. An approximately 8 week live fetus was seen within the sac.

Click images to enlarge

Fig. 1 TVS

She underwent treatment with local injection of methotrexate into the gestational sac. Serial titers of B-HCG progressively fell; however, after two weeks, profuse vaginal bleeding ensued. Emergency hysterectomy was performed.

Fig. 2 TAS

Discussion
Although an admittedly rare entity, the rise in Cesarean births may affect its incidence. The spate of recent articles suggests this may be the case. Therefore, all who provide prenatal care need to be aware of this form of ectopic pregnancy. In our case, the incisional endometriosis undoubtedly became an additional risk factor.

Since scar ectopic is so rare, a consensus about treatment does not exist. Most reviews consist of case reports.¹ Both medical and surgical therapies have been utilized successfully. In our case, local injection met with initial success. Despite falling levels of HCG, the onset of hemorrhage necessitated emergency surgery.

One technical note concerning the ultrasound needs mentioning. After Cesarean, we have found the uterus often adherent anteriorly and pulled superiorly out of the focal range of the vaginal transducer, negating the higher resolution. Therefore, TAS, with its more panoramic field of view, can be more helpful in demonstrating the true nature of the pathology. Moreover, with the development of harmonic technology, diagnostic images are usually obtained without the need for bladder-filling.

References:

• Fylstra DL Ectopic pregnancy within a Cesarean scar: a review. Obstet Gynecol Survey 2002; 57: 538-543.