A molar pregnancy occurs when the fertilisation of the egg by the sperm goes wrong and leads to the growth of abnormal cells or clusters of water filled sacs inside the womb. This condition is one of a group of conditions known as gestational trophoblastic tumours (GTTs). Molar pregnancies used to be called hydatidiform mole but now most people call them molar pregnancies. Most molar pregnancies are benign (not cancerous). They can spread beyond the womb in some women, but are still curable.
Complete molar pregnancy – when the egg with no genetic information is fertilized by a sperm or when the nucleus of an egg is either lost or inactivated. The sperm grows on its own, duplicates itself because the egg was lacking genetic information but it can only become a lump of tissue. It cannot become a foetus. Usually there is no foetus, no placenta, no fluid and no amniotic membranes. As this tissue grows, it looks a bit like a cluster of grapes. This cluster of tissue is called a mole and it can fulfil the uterus. The uterus is rather filled with the mole that resembles a bunch of grapes.
In the past GTD was often fatal. However, medical advances in the past 50 years mean that the disease is now invariably curable. Almost 100% of patients with benign tumours, or metastatic tumours are successfully cured and most women retain their fertility following treatment. Transvaginal and transabdominal ultrasound are also commonly used diagnostic tools, which enable doctors to see signs of molar pregnancy. The doctor will take an ultrasound of the areas likely to be affected if a molar pregnancy is in fact occurring, and examine the ultrasonic images for evidence of GTD.