To explore the characteristics of abdominal pregnancy (AP) and provide clinical reference for its diagnosis, treatment and management.

From January 2008 to December 2018, a total of 37 patients with AP who were admitted to West China Second University Hospital, Sichuan University were selected as research subjects. Among them, there were 36 cases and 1 case of AP in the first and second trimester, respectively. General clinical data, clinical manifestations, auxiliary examination results, diagnosis, treatments, gestational sac implantation site, postoperative pathology and recovery of AP were collected by retrospective method, and their clinical characteristics were analyzed. This study was in accordance with World Medical Association Declaration of Helsinki revised in 2013.

The clinical characteristics of 36 cases in the first trimester were as follows. ①General clinical data: preoperative serum β-human chorionic gonadotropin (hCG) value was 2 594.9 mIU/mL (179.1-173 450.0 mIU/mL); 34 cases (94.4%) were natural pregnancy and 2 cases (5.6%) were by fertilization in vitro-embryo transfer; there were 1 case of pregnancy with intrauterine device in situ and 1 case with intrauterine pregnancy, the other 34 cases (94.4%) were not combined with other kind of pregnancy. ②Clinical manifestations: 35 cases (97.2%) had a period of amenorrhea ranging from 29 to 76 d, 1 case (2.8%) had an unknown period of amenorrhea; 33 cases (91.7%) had varying degrees of abdominal pain; 26 cases (72.2%) had vaginal bleeding. ③Preoperative diagnosis results: only 3 cases (8.3%) were diagnosed as spleen pregnancy by ultrasound combined with serum β-hCG and clinical manifestations before operation, but 2 cases were misdiagnosed as fallopian tubal pregnancy (FTP) in other hospital institutions, and salpingectomy has been performed on the affected side. The other 33 cases (91.7%) were not diagnosed before operation. ④Treatments: 34 cases (94.4%) underwent laparoscopy; as to the other 2 cases, 1 case (2.8%) underwent laparotomy, 1 case (2.8%) was converted to laparotomy for extreme difficulty in exposure of surgical field during laparoscopic surgery, and both cases underwent splenectomy. ⑤Postoperative pathological examination results showed that 35 cases (97.2%) suggested pregnancy; 1 case (2.8%) did not show pregnancy, but the value of serum β-hCG decreased gradually and returned to normal level 14 days after operation. ⑥Prognosis: all patients recovered well after operation, none serious complication occurred, and the value of serum β-hCG decreased significantly in the first reexamination time (one to three days after operation). Clinical characteristics of a patient with AP in the second trimester were as follows. ①She was misdiagnosed as intrauterine pregnancy by ultrasound before operation, and received drug induced labor and clamping under ultrasound monitoring in our hospital, but all failed. Finally, exploratory laparotomy was performed to remove a dead fetus and placenta. ②Treatment and prognosis: after operation, complications such as coagulation dysfunction, shock and repeated mild fever occurred in this patient. After blood transfusion, anti-shock and anti-infection treatment, the patient gradually recovered and discharged from hospital on the 14th day after operation.

Diagnosis and accurate positioning of gestational sac of AP in the first trimester are difficult. It is easy to be misdiagnosed, especially when the implantation site is in upper abdominal cavity and secluded spot. Most of the AP gestational sac in the first trimester are still planted in pelvic cavity, and mainly diagnosed by surgical exploration. Laparoscopic surgery is a recommended method for termination of pregnancy of AP patients in the first trimester. AP in the second trimester is easy to be misdiagnosed by ultrasound. Due to the complicated and changeable condition of AP, once misdiagnosed, it can lead to an increased risk of pregnancy. Therefore, patients with suspected AP should be strengthened in monitoring and individualized management.