Background: Twin pregnancy consist a healthy fetus, and hydatidium molar pregnancy is unusual and very rare. Its incidence is in about 1,22,000 to 1,100,000 of all pregnancies. This type of pregnancy is commonly associated with several obstetric complications requiring early termination of pregnancy. Managing a twin mole pregnancy with normal and live fetuses is controversial, although this unusual type of abnormalities in most cases leads to abortion or intrauterine fetal death. In other hand, due to the high probability of obstetric complications during pregnancy, such as preeclampsia in 25% of cases, metabolic complications such as hyperthyroidism and vaginal bleeding pregnancy is terminated. Survival of the normal coexisting fetus is variable and depends on whether the diagnosis is made, and if so, whether problems from the molar component. Present study reported a case of coexisting mole and live fetus twin pregnancy with successful outcome.
Case presentation: A 35 years old woman, G2ab1 which was diagnosed to have twin pregnancy with mole and coexisting live fetus in 11 weeks of gestational age was referred to obstetric department of Ghaem Hospital, Mashhad University of Medical Sciences, Iran in January 2017. Close follow-up and obstetric surveillance had performed for her and at the last her pregnancy was terminated in gestational age of 36 weeks; a healthy male infant. The β-human chorionic gonadotrophin (BhCG) levels still is undetectable after one year.
Conclusion: Twin pregnancy with one normal fetus and a co-existing molar pregnancy could be continued under close surveillance if the live fetus has normal karyotypes and no structural anomaly and decreasing level of serum BhCG level during the time. Close monitoring necessary even after termination due to increasing risk of persistence trophoblastic disease after termination, what was performed in this case also.
