On this website we hope to give an introduction to molar pregnancies and gestational trophoblast disease that will be of value to our patients, referring medical teams and other interested readers and health professionals.

All forms of gestational trophoblast disease (GTD) are rare and we are fortunate in the UK to have a national service for their follow up and treatment. The centre at Charing Cross has treated over 3500 patients with the various forms of trophoblast disease giving us the largest experience of this disease worldwide.

GTD forms a spectrum of illnesses that are rare, almost always curable but not always well understood. The types of trophoblast disease range from the usually benign partial molar pregnancy through complete molar pregnancy and invasive mole to malignant choriocarcinoma and the rare placental site epithelioid trophoblast tumours. All of these illnesses share the characteristic that they arise from a pregnancy.

In a molar pregnancy, at the time of conception, the fertilised cell becomes abnormal as a result of an imbalance in the number of chromosomes supplied from the mother and the father. The molar pregnancy cells that result can grow quickly, produce hCG (human chorionic gonadotrophin)and so give a positive pregnancy test but are unable to form a proper embryo. Most molar pregnancies are diagnosed relatively early on in pregnancy and treatment by evacuation is sufficient in most cases to be curative. Those who require further treatment after surgery usually need chemotherapy which is curative for nearly all patients and has much less side-effects than most people expect.

There is further information on molar pregnancies, their diagnosis, treatment and the UK follow up service in the information pages for patients and clinicians. Further information can also be found in our leaflets on GTD and Life After GTD.