Trophoblastic disease

Increased risk

Factors that increase the risk of molar pregnancies are thought toinclude:

Age complete molar pregnancies are more common in teenage women and women over 45 years old. Age has little or no effect onthe risk of partial molar pregnancy.
Previous molar pregnancy if you have had one molar pregnancy before, your chance of having another one is around one to two in 100, compared with one in 600 for women who haven't had a molar pregnancy. If you have had two or more molar pregnancies, your risk of having another is around 15-20 in 100.
Ethnicitymolar pregnancies are most common in Asian countries, such as Taiwan, the Philippines and Japan, and also among Native Americans. However, in recent years, the differences in the incidence of molar pregnancybetween these communities andthe general populationhave become less marked.

Types of molar pregnancy

There are two main types of molar pregnancy, depending on the balance of chromosomes in the egg. These are:

complete moles when no normal placental tissue forms and no foetus develops; instead, a mass of abnormal cells grow
partial moles when some abnormal placental tissue forms along with someabnormal foetus; the foetus cannot develop into a baby

In very rare cases, a twin pregnancy can include a normal foetus and a mole.

Symptoms and diagnosis

There are often no signs that a pregnancy is amolar pregnancy. In most cases, the problem is first spotted during an ultrasound scan, which may be the first pregnancy scan at 10-14 weeks.

If there are symptoms, they usually appear between weeks 4 and 12 of pregnancy. The most common symptom is bleeding or losing brown-red fluid from the vagina.

Sickness and vomiting may be more severe than in a normal pregnancy.

Bleeding usually requires an ultrasound scan. If this scan is abnormal, an evacuation of the uterus is performed. This is when the molar pregnancy is removed, usually with a surgical procedure called suction evacuation.The surgeryinvolves opening your cervix (neck of the womb) with a small tube known as a dilator, and removing any remaining tissue with a suction device. Tissue from the pregnancy is then sent to a laboratory to confirm whether it is a molar pregnancy.

If a woman has a miscarriage or a termination for other reasons, tissue may be sent to a laboratory for analysis. This may confirm that the pregnancy was molar, even if a molar pregnancy wasn't suspected.

Treatment

A molar pregnancy usually needs to be removed surgically. This is done with a suction evacuation, under the care of a gynaecologist.

In some cases, molar pregnancy can be treated with the removal of the womb( Hysterectomy ), but this is usually only if you no longer wish to have children.

Almost all cases of molar pregnancy are successfully cured.

For further information, go to the Charing Cross Hospital Trophoblast Disease Service or the The Sheffield Trophoblastic Disease Centre websites.