Prenatal diagnosis and clinical management of a twin pregnancy consisting of a complete mole and coexisting fetus

Objective To discuss the differential diagnosis of the hydatidiform mole and a coexisting fetus,to study the prenatal diagnosis and the clinical management of a twin pregnancy consisting of a complete mole and coexisting fetus(CMCF). Methods Two cases of CMCF were reported retrospectively. Results In the first case,the hydatidiform mole and a coexisting fetus was found by B mode ultrasound at the 10th gestational week,the patient asked to terminate the pregnancy. The interphase FISH and karyotype analysis of the normal villi and the mole showed both of them were diploid,thus the CMCF was diagnosed. In the second case,the hydatidiform mole and a coexisting fetus was found by B mode ultrasound at the 21st gestational week. Transabdominal chorionic villi sampling and amniocentesis was performed,interphase FISH and karyotype analysis of the mole and the amniotic fluid showed both of them were diploid,thus the CMCF was diagnosed prenatally. The pregnancy was continued and premature rupture of membrane happened at the 28th gestational week,the cesarean section was performed. The neonate was healthy. The karyotype analysis of the placenta and the neonate was accordant with the prenatal diagnosis. Conclusions As long as the hydatidiform mole and a coexisting fetus was found the prenatal diagnosis must be performed in order to differentiate the CMCF and the partial hydatidiform mole(PHM). The transabdominal chorionic villi sampling and the amniocentesis were ideal methods,interphase FISH and karyotype analysis of the mole and the amniotic fluid should be performed. If both of them were diploid,the CMCF could be diagnosed. The clinical management of CMCF should be done individually.If both of them were triploid,the PHM could be diagnosed.