A BRCA1+ Patient with Twin Pregnancy of a Complete Mole with Complete Fetus

Abstract

Title: A BRCA1+ Patient with Twin Pregnancy of a Complete Mole with Complete Fetus

Authors: Yaqub, A., Tominack, H., Ungureanu, I., Ganapaneni, S., Tian, W. MD, Scifres, C. MD, & Robertson, S. MD

Background: A complete molar pregnancy is a non-viable pregnancy that results from the implantation of a diploid fertilized egg containing no maternal DNA. Twin pregnancy of a complete mole with complete fetus (CMCF) is a very rare occurrence with an incidence of 1/22,000 to 1/100,000 pregnancies. Continuing a CMCF pregnancy can result in many risks to the health of the mother and fetus.

Case: A 35-year-old G3P2 female presented to an obstetric scan at 20 weeks gestation, which was suspicious for both a viable fetus and a molar pregnancy. She had no significant medical history other than being BRCA1+, with two previous uncomplicated pregnancies. Her initial ultrasound at 10 weeks gestation was indeterminate on whether this was a partial mole vs CMCF. The patient was offered the option to terminate the pregnancy due to risk of complications but chose to proceed with the pregnancy. Because she was BRCA1+ with a strong family history of breast and ovarian cancer, she had a planned Cesarean-hysterectomy with bilateral oophorectomy at 34 weeks. Mother and infant were discharged on postoperative day 2, and the pathology report of the placenta confirmed the removal of a complete mole. Serial β-hcg levels were followed after delivery.

Clinical Significance: Due to the high risk of complications, pregnancy termination is typically offered to patients in this situation. Patients who choose to continue the pregnancy should be thoroughly informed of potential complications. Risks associated with continuing a CMCF pregnancy include preeclampsia, vaginal bleeding, intrauterine death of the fetus, and the development of gestational trophoblastic disease. This patient was also complicated by being BRCA1+, which impacted surgical planning.

Conclusion: CMCF pregnancy is a rare occurrence with many associated risks. In BRCA1+ patients who choose to continue a CMCF pregnancy, extensive counseling is necessary with consideration for risk-reducing surgical management at time of delivery.