Methotrexate for management of twin pregnancy with complete hydatidiform mole and co-existing live fetus

INTRODUCTION AND IMPORTANCE: Here, we discuss novel management with methotrexate for the rare case of a complete hydatidiform mole with a co-existing fetus (CHMCF). The management of CHMCF is controversial, and methotrexate might represent a solution. CHMCF management with methotrexate needs more study, especially its side effects, safe dosage, and the permissible period of pregnancy. CASE PRESENTATION: A 23-year-old Syrian primigravida came to our hospital with vaginal bleeding. The patient was diagnosed with a complete hydatidiform mole with a co-existing fetus. The mother had no complications but elevated B-HCG. After counseling, the decision was made to continue pregnancy with methotrexate to control B-HCG levels. The outcome was favorable though the infant had tetralogy of Fallot. CLINICAL DISCUSSION: In our case, the patient was stable except for the elevation of B-hCG levels, so we considered methotrexate to control it. On the other hand, methotrexate is considered a human teratogen. Case reports and case series of exposure to it during pregnancy began appearing in the 1960s. The sensitive period is suggested to be 6 to 8 weeks after conception. After discussing the choices with the patient, she elected to continue pregnancy and accepted methotrexate exposure to control B-hCG levels despite its risks. CONCLUSION: Methotrexate usage within a safe dosage should be studied more to determine the benefits and risks it carries in cases such as ours.