Maria has been living in China for several years, but she spoke neither Chinese nor English. In March this year, after 9 weeks of amenorrhea, she visited the Department of Gynecology at Clifford Hospital. Tests showed her total human chorionic gonadotropin (hCG) level was as high as 9403.00 IU/L, a clear sign of pregnancy. However, the ultrasound results were puzzling: no gestational sac was found either inside or outside the uterus. Over the following days, her hCG level continued to rise, reaching 12,844 IU/L, indicating that the pregnancy was still developing. But where was it?

Determined to find the answer, the gynecology team worked closely with Associate Chief Physician Dr. Chen Limin from the Department of Ultrasound. They expanded the ultrasound examination to include the liver, gallbladder, pancreas, spleen, and kidneys.

Finally, a suspected gestational sac was identified above the umbilicus, in a perilous location immediately adjacent to the abdominal aorta — the body’s largest blood vessel — and the inferior mesenteric artery. Embedded behind the peritoneum and measuring approximately 3.5 × 3 cm in diameter, it lay only millimeters away from major blood vessels, like a ticking time bomb that could trigger fatal massive hemorrhage at any moment.

Multidisciplinary Collaboration for Precise Resection of the Retroperitoneal Gestational Sac

According to Chinese Journal of Obstetrics and Gynecology, retroperitoneal ectopic pregnancy is an exceptionally rare condition, occurring in approximately 1 in 180,000 pregnancies.

Given the life-threatening nature of Maria's condition, the Department of Gynecology immediately organized a multidisciplinary team (MDT) consultation. After a thorough discussion, the specialists agreed that surgical intervention was necessary to locate and remove the ectopic pregnancy. A laparoscopic procedure was planned to ensure precise treatment while minimizing surgical trauma.

On March 18, the operation was performed under the full support of the Department of Anesthesiology. The surgical team included Director Dr. Guo Yuzhen , Associate Chief Physician Dr. Dai Lina, Dr.Xie Hongyunmeng, and Director Dr. Cui Dongming from the Department of General Surgery, who worked together throughout the procedure.

During the laparoscopic exploration, no gestational sac was found in the uterus, fallopian tubes, or abdominal cavity. Guided by the preoperative ultrasound findings, the surgeons carefully searched the area above and to the right of the umbilicus. After a meticulous exploration, they finally located the gestational sac hidden deep within the retroperitoneal space.

The mass measured approximately 4 × 4 cm, appeared purplish‑blue, and had clear borders but dense adhesion to surrounding tissues. It was located to the right of the abdominal aorta and below the duodenum - a rupture would have caused fatal massive hemorrhage.

Rising to the challenge, the surgical team worked in seamless coordination. Using an ultrasonic scalpel, they carefully separated the adhesion along the border of the mass as if defusing a bomb, advancing cautiously through the “minefield” of blood vessels and intestines, and gradually freed the mass from surrounding tissues. The mass was ultimately completely resected. Intraoperative rapid frozen section confirmed the tissue as gestational tissue. Any delay in surgery would have had catastrophic consequences.

Three days after surgery, Maria's serum hCG level dropped to 910 IU/L, indicating a successful outcome. She recovered well and was discharged safely.

The Dangers of a “Lost” Fertilized Egg and Warning Signs

This challenging case not only demonstrated the successful treatment of an exceptionally rare and life-threatening condition, but also highlighted Clifford Hospital's strength in multidisciplinary collaboration and international patient care.

Faced with both a critical medical emergency and significant language barriers, the hospital leadership acted promptly to coordinate resources across multiple departments. Through close collaboration and efficient communication, the multidisciplinary team provided timely, safe, and highly specialized care, ultimately helping Maria overcome this life-threatening condition.

Before leaving the hospital, Maria and her husband expressed their sincere gratitude to the entire medical team. They spoke highly of the professionalism, dedication, and compassionate care they received throughout their treatment.

However, they still had one question: How could the pregnancy have implanted in such an unusual location?

What Is an Ectopic Pregnancy?

Dr. Guo Yuzhen, department director, explained that in a normal pregnancy, fertilization takes place in the fallopian tube. The fertilized egg then travels into the uterus, where it implants and develops.

When the fertilized egg implants outside the uterine cavity instead of reaching the uterus, the condition is known as an ectopic pregnancy.

Tubal ectopic pregnancy is the most common type, accounting for approximately 1–2% of all pregnancies. Abdominal ectopic pregnancy is a rare subtype, making up only 1% of all ectopic pregnancies. It has an insidious onset, atypical symptoms, and is difficult to diagnose in the early stages. Once rupture and bleeding occur, the hemorrhage is often rapid and severe.

Retroperitoneal ectopic pregnancy (REP) is a special type of abdominal pregnancy and extremely rare. Implantation sites typically include the space between the inferior vena cava and abdominal aorta, the junction of the abdominal aorta and left renal artery, the left renal region, and the psoas major near the abdominal aorta, as well as the retroperitoneum.

According to an academic review in Clinical Obstetrics and Gynecology, only 55 cases had been reported worldwide as of 2023, and the mortality rate is 8 times higher than that of non‑abdominal pregnancies.

Expert Advice

Dr. Guo reminds women of reproductive age to seek medical attention promptly if they experience any of the following symptoms after a missed menstrual period:

• Abdominal pain
• Irregular vaginal bleeding
• Persistently elevated hCG levels without a visible gestational sac on ultrasound

Early diagnosis and timely treatment are essential to preventing serious complications and protecting maternal health.