[Twin pregnancy with complete hydatiform mole and coexistent fetus: Report of 4 cases and review of literature].

OBJECTIVE: Twin pregnancy with complete hydatiform mole and coexistent fetus is a rare clinical condition, occurring in 1 in 22,000 to one in 100,000 pregnancies. Continuation of pregnancy in these cases is controversial because of a high risk of immediate and long-term maternal morbidity. It allows, however, in 33 % of the case the delivery of a healthy child.

METHODS: This retrospective study included all patients presenting a complete hydatiform mole coexisting with a live twin fetus antenatally diagnosed between 2007 and 2012 in the level III maternity of the Strasbourg University Hospital. Informations concerning diagnostic circumstances, pregnancy follow-up and outcome were studied.

RESULTS: Four pregnancies were included in the study, all of them were spontaneous. Medical termination of pregnancies was related to maternal reasons in the four cases. One before 17 weeks of gestation, the three other after 2 weeks of gestation, leading to delivery of a healthy child. All patients developed a mild to severe preeclampsia. One patient developed a gestational trophoblastic disease, requiring chemotherapy by methotrexate. There was no fatal evolution.

CONCLUSION: Twin pregnancy with complete hydatifom mole and coexistent fetus is associated with increased risk of gestational trophoblastic disease. This risk is not increased by continuation of pregnancy. In case of prenatal diagnosis of complete hydatiform mole coexisting with a live twin fetus, patients should be aware of the potential high risk of morbidity and a regular follow-up during and after the pregnancy should be intaured. In absence of maternal complications, continuation of the pregnancy is possible.