Symptoms of molar pregnancy

Molar pregnancies are not cancer (they are benign). There is a very small risk that the molar cells could become cancerous if they are not all removed.

Read more about molar pregnancy

Vaginal bleeding

Vaginal bleeding is the most common symptom of a molar pregnancy. Bleeding can also happen during a normal pregnancy and is not always serious. Tell your doctor or midwife straight away if you have any bleeding.

Women with a molar pregnancy are more likely to pass blood clots. Or have a watery brown vaginal discharge. Some women pass pieces of the molar tissue, which can look a bit like small bunches of grapes. Bleeding caused by a molar pregnancy usually begins between weeks 6 and 12 of pregnancy.

Less common symptoms

The following symptoms are uncommon. This is because most molar pregnancies are found during routine ultrasound scans carried out in early pregnancy.

Abdominal swelling

Some women who have a complete molar pregnancy might have a larger abdomen (tummy). Their tummy might get bigger more quickly than in a normal pregnancy. So your doctors or your midwife may say that you are large for your dates.

In women with a partial molar pregnancy, the womb and abdomen might be smaller than expected for the stage of pregnancy. 

Read more about complete and partial molar pregnancy

Feeling and being sick

Feeling and being sick are common in a normal pregnancy. But with a molar pregnancy the sickness can be more severe and might happen more often. This is called hyperemesis gravidarum.

Anaemia (low red blood cells)

Anaemia means that you have a low number of red blood cells in your body. Red blood cells carry oxygen around your body. If you're losing blood because of vaginal bleeding, your red blood cell count may get low. Being anaemic can make you feel tired and breathless.

Abdominal pain

Some women might have abdominal (tummy) pain or discomfort.

Pre eclampsia

Pre eclampsia is a complication that can happen in the last 3 months of a normal pregnancy. The main symptoms are high blood pressure and protein in your urine. In a molar pregnancy pre eclampsia can happen much earlier on.

Overactive thyroid

The medical term for this is hyperthyroidism. It can cause diarrhoea, a fast heartbeat, severe tiredness and twitching.

When to see your doctor or midwife

If you have any of these symptoms see your GP or midwife. They will refer you to a specialist for tests. The tests usually include an ultrasound scan and blood tests to check the levels of a hormone called human chorionic gonadotrophin (hCG).

Find out about how molar pregnancy is diagnosed