A 39-year-old woman, G7P3, with 3 healthy children. Her last delivery was in 2013. Approximately 45 days ago, an ultrasound at a local clinic revealed a 2-month intrauterine pregnancy, and a medical abortion was conducted subsequently on patient's request. This was followed with uterine curettage because of abortion failure. The medical records of the patient could not be traced back. After the operation, the patient had vaginal spotting for 5 days, and no more vaginal bleeding or menstrual cramps at the time of consultation. One month after the operation, the patient presented with palpitation and nausea. The local hospital's ultrasound displayed that the uterus was 8.4 x 6.4 x 6.1 cm large, and the gestational sac was 11.2 x 10.5 x 8.1 cm, and was cited on the left posterior uterus. The fetus was visible inside; the double parietal diameter was 3.2 cm, and the amniotic fluid depth was 3.3 cm, indicating an abdominal pregnancy. Therefore, the patient was transferred to our hospital.
The patient's body temperature was 37.5  C when admitted to our hospital, and she had intermittent mid-abdominal pain. No lower abdominal pain or swelling or vaginal bleeding was observed. Laboratory examinations revealed that the white blood cells were in the normal range, but the proportion of neutrophils had increased to 84.6%, accompanied by an increase in hsCRP of 31.83 mg/L, as well as mild hypokalemia, hypoproteinemia, and mild anemia. Further, beta-HCG level was 55,264.9 IU/L. An ultrasound revealed that the uterus was enlarged, the endometrial thickness was 0.8 cm, and the gestational sac was located on the left rear side of the uterus. A formed fetus was seen inside, with a fetal BPD of 3.6 cm, fetal abdominal circumference of 10.6 cm, and fetal femur length of 2.2 cm. The fetal heartbeat was visible, and amniotic fluid depth was approximately 4.0 cm. The placenta was located in the right front of the left iliac blood vessel, with a thickness of approximately 3.5 cm and a length of approximately 16.1 cm. There was no obvious free liquid in the pelvis. The diagnosis was confirmed after magnetic resonance imaging (MRI) (Fig. 1). On MRI, the posterior, right, and anterior pelvic short T1 signals around the placenta were considered as bloody effusions. Vascular ultrasound and angiography confirmed that the blood supply to the placenta came from the left uterine artery and left ovarian artery. Gelatinous sponge particles were used to embolize the left uterine artery and left ovarian artery, and the embolization was smoothly conducted. After 1 h, ultrasound imaging indicated that the fetal heart had stopped beating. Except for slight abdominal pain, there were no other discomforts to the patient later that night.
After sufficient preparation, the patient was sent to the operating room for an exploratory laparotomy. During the operation, the gestational sac was seen behind the uterus, with a formed fetus in it, and the amniotic fluid was clear (Fig. 2). The fetus was taken out after ligating the umbilical cord, and the appearance of the fetus had no deformity. After observing for 30 min, except for slight blood oozing from the edge of the placenta, no other evidence of placental abruption was observed. We decided to leave the placenta at site and close the abdomen. The amount of bleeding during surgery was estimated to be 50 ml, and no blood transfusion was required. After the operation, the patient's body temperature increased to 38.1 C, but soon decreased after antibiotic treatment. There was no decrease in hemoglobin levels on the 1st, 3rd, and 8th day after the operation. On the 10th day after the operation, ultrasound-revealed medium echo at the back of the uterus was approximately 7.8 cm long and 4.5 cm thick. There were scattered small echoes but no obvious blood flow signals within. The patient was discharged from the hospital and followed up regularly at the outpatient clinic. The blood beta-HCG returned to normal on the 26th day after the operation, but ultrasound still showed a moderate echo of 6.2 x 5.2 x 4.3 cm behind the uterus. The patient has no discomfort and is still under close follow-up.
We reviewed the cases of abdominal pregnancy that were treated at our hospital and confirmed by intraoperative findings and pathological results. That is, all the cases with "abdominal pregnancy" in the discharge diagnosis were searched in the medical record retrieval system, and the cases with unclear diagnosis and repeated hospitalization were excluded. A total of 17 cases including the current case have been treated at our hospital, and the pregnancy history, diagnosis, treatment, and complications of these patients were analyzed, with an aim to achieve a reference for this case and other similar cases.
All 17 cases occurred between 1989 and 2021, in this period, the total number of deliveries and ectopic pregnancies diagnosed in our unit were 62,121 and 9095, respectively. Abdominal pregnancies accounts for approximately 0.19% of all ectopic pregnancies. Among all 17 abdominal pregnancy patients, the median age was 34 years (22-42 years), and the median gestation was 57 days (41 days to 32 weeks). All patients had symptoms, and 15 of 17 (88.24%) had abdominal pain; 7 of 17 (41.18%) patients had vaginal bleeding. The implantation sites of the gestational sac were bladder peritoneal reflection, anterior rectal wall, greater omentum, uterine serosa, medial uterosacral ligament, or uterosacral ligament (Fig. 3). Further, 29.41% (5/17) of patients were diagnosed before surgery, and the other 70.59% (12/17) were misdiagnosed with tubal pregnancy or unexplained intra-abdominal hemorrhage (patients in early pregnancy) and central placenta previa (patients in third trimester) before surgery. The primary method of preoperative evaluation was ultrasound, and it was not until 2020 that MRI and angiography were first added to preoperative diagnostic procedures for suspected abdominal pregnancies (Fig. 4). All 17 patients were treated by laparoscopy or open surgery, no conservative/non-surgical management. Subsequently, 58.82% (10/17) recovered without complications after treatment, 29.41% (5/17) developed fever, which improved after antibiotic treatment, 5.88% (1/17) developed intra-abdominal hemorrhage and hemorrhagic shock, and had to undergo a reoperation, and 5.88% (1/17) had venous thrombosis in both lower extremities and needed additional anticoagulation therapy. No deaths occurred (Table 1).
The gestational age of 13 of 17 (76.47%) patients was less than 20 weeks; of these 2 patients were diagnosed before treatment, and both were in the second trimester and the fetal heartbeat could be seen on imaging. Both these patients underwent laparotomy. Among these two, one patient developed venous thrombosis in both lower extremities after operation. Among the remaining 11 cases that were not diagnosed before operation, three were presumed to be secondary to a recent tubal ectopic pregnancy, although the abnormal tube was removed in two cases during a previous operation; the remaining 8 were primary cases. In addition, all 11 patients in the first trimester were not diagnosed by imaging examinations before surgery; 10 of them had abdominal pain, but 7 of these 10 (70%) were misdiagnosed with tubal pregnancy; four patients received blood transfusion because of gestational sac implanting site rupture and suffered heavy bleeding. The pregnancy tissue was successfully removed in all 11 patients through laparoscopic surgery, and blood beta-HCG levels fell to the normal range within 1 month after the operation (Table 2).
In all, 9 of 13 (69.23%) patients with a gestational age of less than 20 weeks had high risk factors for an abdominal pregnancy: 1 patient was fertilized by ovulation induction because of primary infertility; 2 had intrapelvic adhesions; 2 had cysts in the fallopian tubes; 2 had a history of pelvic surgery, particularly fallopian tube surgery; 1 had a history of uterine cavity operation in early gestation and 3 had a history of tubal ectopic pregnancy confirmed by laparoscopy and pathology.
Overall, 23.53% (4/17) of patients had AAP, that is, gestational age > 20 weeks. All four cases were observed in 2000s and before. All four patients had symptoms of abdominal pain, three were diagnosed by imaging examinations before surgery, and all received blood transfusions because of excessive bleeding during the perioperative period. Among the four patients, there was one fetal malformation, one stillbirth, and one live birth. With regard to the placenta, in two cases, the placenta was attached to a fallopian tube and ruptured uterus with remnant uterine horn, respectively. This is speculated to be secondary to tubal pregnancy and remnant uterine horn pregnancy. The four patients were treated via laparotomy. In one patient, the placenta attached to the left fallopian tube was removed during the operation, and the placenta was left in site in three other cases. However, one patient showed intra-abdominal hemorrhage and hemorrhagic shock on the same day; thus, the patient needed another surgical treatment. During the second operation, it was found that the placenta remained in situ attached to a ruptured residual uterine horn, which was not accurately recognized by imaging before and during the first operation. Another patient underwent another laparotomy 26 months later because of another ectopic pregnancy ruptured in the left fallopian tube, and the remaining placenta was removed during this operation. All four patients developed fever after operation, but antibiotic treatment was effective, and they were discharged after a good recovery.
Overall, 50% (2/4) of patients had high risk factors for abdominal pregnancy in this patient group. Among the two patients, one had a history of uterine cavity operation in early pregnancy and the other was naturally conceived after four years of infertility.