Ectopic Pregnancies in Unusual Locations

Thomas A Molinaro, M.D.; Kurt T Barnhart,M.D.,M.S.C.E.


Semin Reprod Med. 2007;25(2):123-130. 

In This Article

Abdominal Ectopic Pregnancy

Abdominal pregnancy may account for up to 1.4% of ectopic pregnancies.[54,55,56] Abdominal pregnancies refer to those with extrauterine implantations in omentum, vital organs, or large vessels. These pregnancies can go undetected until an advanced gestational age and often result in severe hemorrhage.[56] Rates of maternal mortality have been reported as high as 20%.[57,58] Advanced abdominal pregnancy carries a risk of hemorrhage, disseminated intravascular coagulation, bowel obstruction, and fistulae.[59] Frequently, these pregnancies are encountered with a viable fetus, which complicates their management.

Implantations have been reported in the pelvic cul-de-sac, broad ligament, bowel, and pelvic sidewall.[55,57,60] The site of implantation and availability of vascular supply are believed to be factors that may influence the possibility of fetal survival.[57] Risk factors for abdominal pregnancy include tubal damage, pelvic inflammatory disease, endometriosis, assisted reproductive techniques, and multiparity.[60,61] Abdominal pregnancies are believed to be a result of secondary implantation from an aborted tubal pregnancy or as a result of intra-abdominal fertilization of sperm and ovum.[55,57]

Patients with abdominal pregnancy often present with abdominal pain, nausea, vomiting, painful fetal movements, and less frequently, vaginal bleeding.[59] In 1942, Studdiford outlined his criteria for abdominal pregnancy: (1) normal bilateral fallopian tubes and ovaries; (2) absence of uteroperitoneal fistula; or (3) presence of a pregnancy related to the peritoneal surface exclusively.[58] Today, the diagnosis of abdominal pregnancy is often made using ultrasound and x-ray. The classic ultrasound finding is the absence of myometrial tissue between the bladder and pregnancy.[57] Elevated serum alpha-fetoprotein has also been associated with abdominal pregnancy.[62] Diagnostic laparoscopy may also be of value when there is a doubt about pregnancy location.[63] In some cases, the diagnosis is not made until laparotomy.[58] Magnetic resonance imaging (MRI) holds promise as a diagnostic tool.[64,65]

Our knowledge of abdominal pregnancies comes largely from anecdotal case reports. Fisch et al[56] reported a case of abdominal pregnancy after IVF in a patient with previous salpingectomy. Omental implantation has been described.[57] Broad ligament pregnancies account for a small number of abdominal pregnancies.[66] Deshpande et al[67] reported a broad ligament twin pregnancy after IVF. The role of possible perforation with an IVF transfer catheter has been raised. There have also been reports of primary omental pregnancies.[58] Splenic pregnancy has been reported in several cases. Kitade et al[68] reported a first-trimester splenic pregnancy complicated by intra-abdominal hemorrhage and necessitating splenectomy. Cormio et al[69] detailed a ruptured splenic pregnancy in a patient who presented in hypovolemic shock.

The optimal treatment of abdominal pregnancy is unknown. Abdominal pregnancies frequently implant in vascular structures such as abdominal organs, omentum, or pelvic vessels. It has been reported that management of the placenta correlates well with maternal morbidity. When possible, ligation of placental blood supply and removal should be attempted to reduce maternal complications.[57,59,60] Alternatively, the umbilical cord may be ligated and expectant management, arterial embolization, or methotrexate used to facilitate involution.[57,64,70] However, leaving the placenta in situ may lead to further complications such as infection, secondary hemorrhage, or intestinal obstruction.[59,65] Laparoscopy has been used in the treatment of some early abdominal pregnancies.[55,63] This conservative management should only be undertaken when the abdominal pregnancy has implanted on a less vascular surface. Olsen et al[71] reported laparoscopic management of a broad ligament pregnancy without complication. Primary methotrexate has been attempted for early gestations with minimal success.[72]

Hemorrhage is the most frequent problem encountered in treating abdominal pregnancy. Rahaman et al[65] used preoperative selective arterial embolization to help prevent hemorrhage in an advanced abdominal pregnancy that was removed laparoscopically. However, due to extensive vascular attachments, the placenta was left in situ and treated with methotrexate. Cardosi et al[70] report a similar experience with selective arterial embolization used as a means of reducing intraoperative blood loss during removal of a 33-week abdominal fetal demise. Ginath et al[73] reported a ruptured abdominal pregnancy successfully managed via laparoscopy, although the pregnancy was only 7 weeks gestation. Furthermore, there are reports of heterotopic abdominal pregnancies treated with laparoscopy with preservation of the intrauterine gestation.[56,74]

Abdominal pregnancy is an extremely rare event that may be difficult to diagnose. The advanced gestational age at which most abdominal pregnancies are discovered complicates management further. Because of the propensity for hemorrhage, removal of abdominal pregnancies requires surgical extraction and discrimination in deciding if placental removal is prudent. There is little information known about future fertility after abdominal pregnancy.


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