Molar pregnancy Hapūtanga tupuranga rerekē o te whenua

A molar pregnancy happens if there are problems when an egg is fertilised and there are too many or not enough genes. Two sperm may fertilise one egg, or sperm may fertilise an egg with no genetic material in it. 

There are 2 types of molar pregnancy.

• A complete molar pregnancy is where no embryo forms. Instead only abnormal placental tissue (trophoblast) grows. This looks like a group of tiny fluid-filled sacs (cysts).
• A partial molar pregnancy happens when an abnormal placenta forms along with an embryo. The embryo may start to develop but it will miscarry.

It is not known exactly why molar pregnancies happen, but women who are younger than 20 or older than 40 are at higher risk.

Women with a molar pregnancy often have higher levels of the pregnancy hormone hCG (human chorionic gonadotrophin) than expected. 

You may have the usual symptoms of pregnancy such as:

• sore breasts
• feeling sick (nausea) or throwing up (vomiting).

You may also have some vaginal bleeding.

An ultrasound scan that you have as part of your routine care or because of bleeding will show your pregnancy will not be able to continue. The scan may also suggest it is a molar pregnancy.

If your midwife or doctor suspects you may have a molar pregnancy, you may also have a blood test to check your hCG levels.

The only way to confirm the pregnancy was a molar pregnancy is by examining and testing the tissue after it is removed under a microscope. This takes about 10 days.

If your hCG levels are high and your ultrasound suggests you may have a molar pregnancy, your midwife or doctor will recommend you have a small operation to remove the pregnancy tissue.

The operation is called an ERPOC or evacuation of retained products of conception. It is also known as a dilation and curettage (D&C). The tissue can then be examined and tested.

Surgical management of miscarriage

Most women's hCG levels will drop back to normal after a molar pregnancy. This drop in hCG shows that all the molar pregnancy cells have gone. But in about 1 in 10 women, some of the abnormal molar pregnancy cells stay in their uterus. These may then grow and spread around their body.

This is known as gestational trophoblastic neoplasia or GTN. It is a type of cancer, but it can be treated successfully with chemotherapy.

If the abnormal cells are present, they keep making hCG. This means women who have had a molar pregnancy should have blood tests to check their hormone levels to make sure the abnormal cells have gone.

The first test is usually done about 10 days after the operation. You will then be seen about 2 weeks after this, when your healthcare provider will be able to confirm whether there definitely was a molar pregnancy. If there was, you will need further testing for at least 6 months.

A molar pregnancy does not affect your ability to get pregnant in the future.

It is important to use contraception to avoid getting pregnant for 6 months after a molar pregnancy and your blood hCG levels have gone back to normal. Because being pregnant also boosts your hCG levels, if you got pregnant it would be impossible to know if your hormones were rising because of pregnancy or because the abnormal cells were coming back.

In any future pregnancies, you should also get blood tests at 6 and 12 weeks to check your hormone levels to make sure the abnormal cells have not come back.

After a molar pregnancy, to avoid getting pregnant you can use:

• hormonal contraception (the Pill, implant or injection)
• condoms.

Contraception

A second molar pregnancy is rare, only happening to around 1 in 80 women. In any future pregnancies, you should have an ultrasound scan at 7 to 8 weeks, to make sure the pregnancy is not another molar pregnancy.

Emotional impact

A molar pregnancy can have a profound emotional impact on you, and also your partner, friends and whānau.

It is normal to feel grief at the loss of a pēpi, even if early in a pregnancy. You may feel this way immediately after, or it may take several weeks to develop.

Other common feelings include anger, guilt and anxiety.

It is important to seek help and support from whānau, friends, or a healthcare provider.