What is the prognosis of hydatidiform mole?

Updated: Feb 16, 2018
  • Author: Lisa E Moore, MD, MS, FACOG, RDMS; Chief Editor: Warner K Huh, MD  more...
  • Print

Because of early diagnosis and appropriate treatment, the current mortality rate from hydatidiform mole is essentially zero. Approximately 20% of women with a complete mole develop a trophoblastic malignancy. Gestational trophoblastic malignancies (ie, gestational trophoblastic neoplasia) are almost 100% curable.

Clinical factors that have been associated with risk of malignant disease are advanced maternal age, high levels of hCG (>100,000 mIU/mL), eclampsia, hyperthyroidism, and bilateral theca lutein cysts. [19]  Most of these factors appear to reflect the amount of trophoblastic proliferation. Predicting who will develop gestational trophoblastic neoplasia remains difficult, and treatment decisions should not be based on the presence of any or all of these risk factors.

A study by Vargas et al indicated that in women who have had molar pregnancies, the outcomes of subsequent pregnancies are similar to pregnancy outcomes in the general population. The study looked at 1388 subsequent pregnancies in women with complete hydatidiform mole, as well as 357 pregnancies following partial hydatidiform mole and 667 pregnancies after gestational trophoblastic neoplasia. Although outcomes in these cases were similar to those of women who had never had a molar pregnancy, the investigators did find that about 1.7% of women with a molar pregnancy did have another molar pregnancy later. Moreover, in women with gestational trophoblastic neoplasia who underwent successful chemotherapy for the disease, the incidence of stillbirth in subsequent pregnancies rose slightly, to 1.3%. [20]

A study by Gadducci et al indicated that women with gestational trophoblastic neoplasia have a good prognosis and that such women who conceive after chemotherapy have similar obstetric outcomes to those of the general population. In the study, 18 of 66 patients with hydatiform mole developed gestational trophoblastic neoplasia and two women were referred with a diagnosis of gestational trophoblastic neoplasia. One of the neoplasia patients died of an epithelioid trophoblastic tumor, with the rest recovering after chemotherapy. Pregnancy was achieved in seven out of eight women who attempted postchemotherapy conception, with 10 conceptions culminating in three miscarriages and seven healthy, full-term births. No molar pregnancies occurred. [21]

In contrast to the results of the above two studies, a report by Joneborg et al suggested that following a molar pregnancy, the risk of preterm birth is increased. The results also indicated that if at least one birth occurs between the molar pregnancy and the index birth, the likelihood of large-for-gestational-age birth and stillbirth is greater. However, the risk of adverse maternal outcomes was not found to be increased following molar pregnancy. The risk of having a repeat molar pregnancy in this study was found to be 0.4%. [22]

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!