Amanda Ecker1 and Richard Guido1
Magee-Womens Hospital of UPMC, 15213, 300 Halket St., Pittsburgh, PA, USA
Amanda Ecker (Corresponding author)
Abdominal pregnancyAbdominal ectopic pregnancy
A 33-year-old multiparous woman (gravida 8, para 7, ectopic 1) presented to the local emergency room (ER) with several days of worsening lower abdominal pain. Her surgical history was significant for a total abdominal hysterectomy 10 weeks prior for a chief complaint of menorrhagia. The patient reported that her last menstrual period had occurred 16 days prior to her hysterectomy and a urine pregnancy test performed on the day of the procedure was negative. Intraoperatively, she was found to have a 10-week-size uterus with no other notable abnormalities and the surgery itself was uncomplicated. In the ER, physical examination revealed a stable patient with a mildly tender lower abdomen in the midline but no features of an acute abdomen. On computed tomography (CT) scan, a 4-cm cystic fluid collection within the pelvis was visualized and felt likely to be consistent with a postoperative hematoma. She was admitted for observation and pain control overnight and then discharged home. Two weeks later, she presented again to the ER with an acute worsening of her pain. Repeat CT of the abdomen and pelvis revealed an enlarged cystic structure (6 × 7 cm) with radiopaque components consistent with fetal parts (Fig. 15.1).
Computed tomography (CT) of the abdomen and pelvis showing a 10-week fetus within the peritoneal cavity. The uterus is surgically absent
Diagnosis and Assessment
An ectopic pregnancy refers to any pregnancy that occurs outside of the endometrial cavity. Abdominal pregnancy is the most uncommon type of ectopic pregnancy with a reported incidence of 1 in 2200 to 1 in 10,200 of all pregnancies . Presenting symptoms range from abdominal pain, mild vaginal bleeding , or painful and excessive fetal movements to hemoperitoneum and hemorrhagic shock in the most severe cases. Rarely, abdominal pregnancy occurs after hysterectomy and, in these cases, an early pregnancy was likely in existence prior to hysterectomy.
There are two proposed etiologies for abdominal pregnancies which include direct implantation on the peritoneum or secondary implantation resulting from tubal abortion or rupture with extrusion of the trophoblastic tissue . Unfortunately, ultrasound sensitivity has been reported at best to be 50 % for identification of abdominal pregnancies, making this a difficult diagnosis to assign .Additionally, serial beta-hCG levels may rise appropriately further confounding the diagnosis . Magnetic resonance imaging (MRI) may be a better imaging modality due to the ability to distinguish between tissue layers based on signal density .In resource-poor settings, a Foley catheter inflated within the lower uterine segment can help ascertain whether the fetus is within the uterus or not .
Due to the risk of infection, peritonitis, and intra-abdominal hemorrhage with maternal exsanguination, surgical intervention is recommended in cases of abdominal pregnancy . There have been rare case reports of conservative management at periviability with inpatient monitoring but this cannot be routinely recommended . Ultrasound and/or MRI can be useful for preoperative planning in demonstrating placental location and vasculature to minimize maternal hemorrhage at time of surgery. Several units of packed red blood cells should be available prior to surgery in the event of hemorrhage requiring transfusion. Hemoglobin and clotting factors should be monitored proactively and aggressively repleted as necessary.
There have been rare reports of successful laparoscopic management of abdominal pregnancy; however, this is only possible if the diagnosis is made at an early stage in the gestational age . At later gestational ages, laparotomy is required for fetal delivery. The more difficult management decisions lie around placental management. There are three options pertaining to the placenta. The first is to attempt removal; however, this should only be pursued if the placenta separates easily and there is no collateral blood supply to adjacent vital organs. The second option is to leave the placenta in situ and await spontaneous resorption. The last option is to leave the placenta in situ but to administer postoperative methotrexate with the goal of expediting placental involution. With this option, there are some concerns surrounding rapid necrosis that may increase bacterial growth and the risk of associated intra-abdominal infection . Unless the placenta is easily removed after fetal delivery, the general recommendation is to leave the placenta in situ.
There are several preoperative strategies that have been previously reported in small series to decrease maternal morbidity. Preoperative methotrexate administration has demonstrated mixed results . Preoperative embolization should be taken into consideration at later gestational ages given the potential for significant hemorrhage and morbidity associated with intervention . Lastly, fetal injection of intracardiac potassium chloride can be considered for fetal termination with a delayed surgery to attempt to decrease vasculature to the abdominal pregnancy .
Maternal mortality rates for abdominal pregnancy can be as high as 18 % with a fetal mortality rate of 90 % . In this particular case, entry into the peritoneal cavity revealed a 10-week fetus floating in 2 L of hemoperitoneum. The fetal tissues were easily removed; however, the placenta was implanted on the sigmoid colon, associated mesentery, and omentum and was unable to be easily removed so was left in situ. She required transfusion with three units of packed red blood cells for intraoperative blood loss and was discharged in stable condition on postoperative day 3. Serum beta-hCG levels spontaneously declined during her admission from 1092 to 499 milli-International Units/mL and as a result, methotrexate therapy was not administered. After discharge, serial beta-hCG levels were monitored and at 2 months were undetectable. Follow-up imaging performed at 6 months demonstrated no remaining visible abdominal masses, consistent with complete placental involution. However, it is important to note that spontaneous involution can be slow to occur; previous studies have reported that it may take up to 5.5 years .
· Urine hCG tests are not always accurate in early pregnancy.
· Delay in diagnosis of abdominal pregnancy after hysterectomy may lead to significant morbidity.
· Abdominal pregnancies are most appropriately managed surgically given the high associated maternal morbidity.
· Placental removal during surgical treatment should only be attempted if placenta easily separates from surrounding structures and has no collateral circulation with other vital structures.
· There is not enough information to recommend for or against pre- or postoperative methotrexate but it can be considered.
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