Uterine serosal pregnancy is an extremely rare form of ectopic pregnancy. This is a report of a 35-year-old primigravida woman who was diagnosed with uterine serosal pregnancy via laparoscopic intervention. A 35-year-old woman (gravida 1, para 0) was referred from a local clinic for a ruptured left tubal pregnancy at amenorrhea 5+0 weeks with elevated serum beta human chorionic gonadotropin (16,618 mIU/mL). A pregnancy on the left posterior wall of the uterine serosa was diagnosed during the operation and successfully treated with laparoscopic surgery as a conservative management strategy to enable fertility preservation. With the advantages of ultrasonography and laparoscopy, an early diagnosis of a primary abdominal pregnancy located on the left posterior wall of the uterine serosa was made, prior to the occurrence of severe intra-abdominal massive hemorrhage, which was then treated laparoscopically as a conservative management strategy enabling the preservation of fertility.
Abdominal pregnancy is a very rare form of ectopic pregnancy where implantation occurs in the peritoneal cavity. While ectopic pregnancy accounts for 2% of all pregnancies, abdominal pregnancy accounts for 1% to 4% of all ectopic pregnancies [
Uterine serosal pregnancy is an extremely rare form of abdominal ectopic pregnancy, wherein the fetus is implanted within the uterine serosa, without a connection to the endometrial cavity, fallopian tubes, or round ligament [
A 35-year-old woman (gravida 1, para 0) with the chief complaint of lower abdominal pain was referred from a local clinic. The presumed diagnosis was ruptured left tubal pregnancy at amenorrhea 5+0 weeks with elevated serum beta human chorionic gonadotropin (16,618 mIU/mL). The patient had no prior medical or surgical history, no history of intrauterine device use, and no history of any assisted reproductive techniques or medications.
Her vital signs were stable and her abdomen was somewhat rigid with tenderness and rebound tenderness noted in the left lower quadrant and suprapubic area. On pelvic exam, minimal cloudy discharge at the cervical os was noted with mild cervical motion tenderness. There was no sign of vaginal bleeding. The laboratory studies were within normal limits including a hemoglobin level of 12.7 g/dL, and serum beta human chorionic gonadotropin level of 17,143 mIU/mL.
The result of a two-dimensional (2D) transvaginal ultrasound (TVS) revealed a gestational sac that was separated from the endometrium along with fluid in the cul-de-sac, suggesting the presence of an ectopic pregnancy. No embryonic pole or yolk sac was seen in the gestational sac. Further investigation by three-dimensional (3D) TVS demonstrated a 1.8-cm mass located adjacent to the left cornus (
Entering the abdominal cavity, a hemoperitoneum of approximately 300 mL was noted, and a 2×2 cm ruptured ectopic mass was dangling from the left posterior wall of the uterine serosa that was distinct from both fallopian tubes, causing active bleeding (
After the diagnosis of uterine serosal pregnancy, surgery was performed with monopolar diathermy scissors, forcing the removal of gestational tissue on the uterine serosa. The ectopic mass was successfully removed via scraping after confirming no remnant chorionic villi tissue. Visible vessels were coagulated with bipolar diathermy, and the uterine scar was meticulously sutured using Vicryl 2-0 (
The pathologic reports confirmed an ectopic pregnancy implanted in the serosa of the uterine posterior wall as the trophoblastic villi was seen microscopically from the removed uterine serosal ectopic mass (
Abdominal pregnancy accounts for 0.6% to 4% of all ectopic pregnancies [
Abdominal pregnancy is classified as either primary or secondary abdominal pregnancy. Primary abdominal pregnancy is defined if implantation occurs initially in the abdomen with normal adnexae and no evidence of injury or uteroplacental fistula [
Considering that all other pelvic organs and both adnexae were macroscopically normal in the present case, with only the ectopic mass in the serosa causing active bleeding, we could conclude that the uterine serosa was the primary implantation site of the pregnancy. We do not exactly know whether the pregnancy confined within serosa or involved myometrium layer microscopically, based on the pathological finding, as the tissue was not viable for further pathologic evaluation. The free fluid observed on ultrasonography, and the intraoperative findings of a ruptured ectopic mass in the left posterior wall of the uterine serosa, with grossly normal adnexae and other pelvic organs, were highly suggestive of a primary abdominal pregnancy. However, these findings could not completely confirm that it was a primary abdominal pregnancy, since they were based on intraoperative findings only, without any clear evidence of the pathogenesis or etiology leading to the implantation of a gestational sac on the uterine serosa.
According to the definition of primary abdominal pregnancy, two possible hypotheses of etiology were made for this case. First, the gestational sac was initially implanted in the endometrium, invaded into the myometrium through a microscopic tract (usually formed by previous uterus trauma or focus of adenomyosis), and eventually implanted on the uterine serosa [
Second, the retrograde passage of a fertilized embryo via the fallopian tubes to the intra-abdomen region with subsequent migration through the lymphatic channels [
The most common diagnostic tool for ectopic pregnancy is 2D TVS, but it may also require 3D TVS to enable more accurate localization of the gestational sac [
In the past, laparotomy was performed in most cases of abdominal pregnancy [
Uterine serosal pregnancy is a rare form of ectopic pregnancy, and the diagnosis is seldom made prior to ectopic mass rupture or surgery. Herein we report a case of uterine serosal pregnancy treated laparoscopically with successful fertility sparing without intra-operative massive hemorrhage.