Successful Spontaneous Twin Pregnancy Following Bone Marrow Transplant and Gastric Cancer Surgery: A Case Report

Introduction

Twin births rates vary considerably around the world, according to country development, from less than 1% of all births in South and Southeast Asia to more than 3% in the USA and France. Variations also exist according to race and ethnicity [1,2]. Multiple birth rates have been rising since the 1970s in developed countries [3], but clinical problems associated with twin pregnancies have been well established, and twin births are now considered undesirable [4]. One of the most serious of these problems is related to cancer.

The increase in the rate of cancer incidence world-wide combined with enhanced mortality in some of the malignancies continues to challenge the biomedical scientific community [5]. Cancer associated with pregnancy or delivery is a rare diagnosis with an incidence of 1/1000–2000 pregnancies. Nevertheless, the prevalence of cancer and pregnancy is increasing due to changing sociodemographic variables, such as increased maternal age due to postponing the start of creating a family [6]. Gastric cancer is prominent in this phenomenon.

With increased early detection of operable gastric cancers via endoscopic screening and a rising trend in advanced maternal age, it is more common that childbearing women undergo gastrectomy for gastric cancer before pregnancy and delivery [7]. Postoperative gastric cancer patients who are pregnant or have delivered a baby often have trouble with malnutrition due to gastrectomy, despite increasing energy needs and the risk of cancer recurrence [8].

Pregnancy after bone marrow transplantation (BMT) is uncommon, but there have been successful cases where patients conceived following discontinuation of immunosuppressive medication [9]. In contrast, the potential for poor prognosis in advanced gastric cancer cases occurring after BMT raises ethical and medical dilemmas regarding treatment prioritization. The complexity of managing both conditions highlights the need for multidisciplinary approaches to optimize care.

Here, we present a case of spontaneous twin pregnancy in a young woman who previously underwent BMT for aplastic anemia and gastrectomy for gastric cancer, and who achieved good maternal and fetal outcomes despite significant obstetric and medical complications.

Case Report

A 22-year-old woman, gravida 1, para 0, presented at 35 weeks 6 days of gestation with a spontaneous dichorionic–diamniotic twin pregnancy in 2024. Her past medical history was significant for severe aplastic anemia, diagnosed approximately 3 years earlier, for which she underwent an allogeneic bone marrow transplant in February 2022. Two months after transplantation, she was diagnosed with gastric adenocarcinoma and subsequently underwent subtotal gastrectomy with bypass reconstruction at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia, in May 2022. A brief timeline is as follows: aplastic anemia diagnosis (approximately 3 years prior to presentation), allogeneic BMT in February 2022, gastric adenocarcinoma diagnosis in April 2022, subtotal gastrectomy with bypass reconstruction in May 2022, and spontaneous dichorionic–diamniotic twin conception in 2024.

The patient was followed antenatally at a tertiary care center at King Fahd Military Medical Complex, Dhahran, Saudi Arabia. At admission, maternal vital signs were stable, and she had no symptoms suggestive of graft-versus-host disease. Baseline antenatal investigations were reassuring, including blood group and antibody screen, infection screening per local protocol, and routine obstetric laboratory tests. First-trimester ultrasound confirmed chorionicity as dichorionic–diamniotic twins. Serial growth scans demonstrated appropriate interval growth, with normal amniotic fluid volumes.

Hematologic surveillance included serial complete blood counts and coagulation profile. During antenatal follow-up, her complete blood count remained stable (hemoglobin 11.8 g/dL, hematocrit 35%, WBC 5×109/L, and platelets 149×109/L), with no transfusion requirement.

During pregnancy, she presented with left lower-limb edema and pain. Compression Doppler ultrasound confirmed deep vein thrombosis involving the femoral vein, with reduced compressibility and absent flow. She had no respiratory symptoms suggestive of pulmonary embolism, and oxygen saturation remained normal on room air. She was started on therapeutic enoxaparin at a dose of 1 mg/kg every 12 h. This choice was guided by pregnancy-associated VTE recommendations favoring low-molecular-weight heparin because it does not cross the placenta and has a good maternal safety profile. Anti-Xa monitoring was considered according to institutional protocol.

While hospitalized, her serum creatinine rose from a baseline of 70 to 145 μmol/L. Renal ultrasound revealed bilateral grade 3 hydronephrosis. Cystoscopy showed normal bladder mucosa and intact ureteric orifices with no intravesical obstruction. Bilateral hydroureteronephrosis was noted, more prominent on the right side, with tortuous ureters bilaterally, consistent with extrinsic ureteric compression in advanced twin gestation. Bilateral double-J ureteric stents (4.8 Fr, 22 cm) were successfully inserted, after which renal function stabilized.

After stabilization, an elective cesarean section was performed at 35+6 weeks. The decision was made through multidisciplinary discussion given dichorionic twin gestation, anticipated adhesions from prior major upper-abdominal surgery, and the need to coordinate perioperative anticoagulation management. The procedure was completed without complications. Both neonates were delivered in good condition. The patient was discharged home on postoperative day 4 in stable condition. At outpatient follow-up, the surgical wound was dry and well healed, and she reported good recovery.

Discussion

Conclusions

Gastric cancer diagnosed during pregnancy generally carries a poor prognosis, mainly due to advanced disease stages at the time of diagnosis, which underscores the importance of early detection. In cases where cancer is active during pregnancy, treatment options such as antenatal chemotherapy may be considered to achieve fetal maturity while balancing risks such as fetal growth restriction, preterm delivery, and neonatal hematopoietic suppression. Diagnostic modalities typically include endoscopy and imaging techniques such as MRI, which are carefully selected to minimize fetal risk. Management strategies vary depending on cancer staging and may involve surgery, adjuvant therapy, or palliative chemotherapy.

In contrast, this case highlights a patient who was cancer-free following gastrectomy before conception. Despite her prior malignancy and bone marrow transplantation, as well as pregnancy-related complications such as thrombosis, obstructive uropathy, and twin gestation, a good pregnancy outcome was achieved through vigilant monitoring and timely multidisciplinary interventions. This case shows that successful pregnancy is possible in such complex clinical scenarios. Continued long-term follow-up remains essential to monitor for potential late complications and recurrence.