Getting pregnant after a molar pregnancy

Molar pregnancy is a pregnancy abnormality that affects the placenta in particular and whose cause occurs at the time of fertilization. Both the placenta and the embryo develop abnormally due to abnormalities of the egg and sperm. There are two possibilities of molar pregnancies. One is called complete, the other is called partial. The outcome of a molar pregnancy is in both cases necessarily negative because the genetic material is incomplete. Let us therefore take a closer look at what these two types of abnormal pregnancies consist of and whether it is possible to become pregnant afterwards.


What is a molar pregnancy?

There are two types of molar pregnancy, one complete and one partial:

A complete molar pregnancy, also known as a complete hydatidiform mole, is the result of fertilisation between two spermatozoa that possess two examples of all the chromosomes, in other words haploid, and an egg without a nucleus, in other words anuclé. An egg without a nucleus is devoid of genetic material. Therefore the embryo is non-existent. Only the placenta can develop. It will grow in the form of bunches of grapes with numerous cysts that can only be detected and seen by ultrasound. It is therefore a pregnancy without an embryo and therefore without the possibility of giving birth.

Partial molar pregnancy with embryo, also known as partial hydatiform molar, is the result of incomplete fertilisation between a complete egg, with nucleus, and at least one haploid sperm. During this type of pregnancy there is an embryo, but it is non-viable because the fertilised egg has too many abnormalities in the chromosomes. The placenta also acts abnormally, as in the case of the complete mole.

In both cases, the pregnancy cannot be brought to term because even when there is an embryo, it cannot be viable.

Symptoms of mole pregnancy

There are two main symptoms: 

First, heavy bleeding and severe anaemia may occur. At the same time, the volume of the uterus may increase. The signs of pregnancy may also become more pronounced and pregnancy toxemia may also be observed. In this case, an endovaginal pelvic ultrasound will have to be carried out in order to find out whether it is indeed a molar pregnancy.

In the case of a rapid or spontaneous miscarriage, this can also be a sign of a molar pregnancy. It is the analysis of the miscarriage that will make it possible to determine whether it is the result of a hydatidiform mole or not. A miscarriage is not necessarily the result of a hydatidiform mole.

If there are no alarming symptoms, only an ultrasound will tell whether the pregnancy is abnormal or not.

What is the treatment?

Whether partial or total, hydatidiform mole is non-viable and can be dangerous for the health of the pregnant woman. Even when there are the right number of chromosomes, these bring a genetic abnormality. There is therefore no chance of life for the embryo. It is therefore necessary to evacuate the abnormal placenta and the embryo if there is one, and to resort to medical treatment. Uterine aspiration is therefore necessary.

After the operation, an anatomopathology is usually carried out to find out what type of mole is involved.

An ultrasound examination must be carried out within two weeks of the uterine aspiration to determine whether there is no longer any retention and whether there are any complications. If there is retention, a second aspiration should be performed.

What are the risk factors?

The only risk of complications of molar pregnancy is the gestational trophoblastic tumour. When the HCG level only increases or stagnates, there is a risk of a gestational trophoblastic tumour. This problem affects about 15% of total molar pregnancies and very few partial molar pregnancies with embryos.

This problem is due to the fact that the molar tissue turns into a tumour. The tumour can then invade nearby organs, especially the uterus. In this case it is called invasive mole or choriocarcinoma. Depending on the results and the type of tumour, chemotherapy will then have to be undertaken.

Can you get pregnant after a molar pregnancy?

It is quite possible to become pregnant after a molar pregnancy. The risk of a second molar pregnancy is extremely low. The risk is between 0.5 and 1% chance of recurrence.

Once the mole has been evacuated, the HCG level must be monitored very carefully and regularly. A weekly blood test should be carried out. If the level is negative three times in a row, then there is no more breakwater. However, it is necessary to follow up regularly even after the negative results, in order to avoid a recurrence.

The HCG level should therefore be monitored for six months after a partial molar pregnancy, and for 12 months in the case of a complete molar pregnancy. If the HCG level is negative in less than eight weeks, the follow-up can be reduced to six months. This monitoring is essential to avoid recurrence of molar pregnancy in the following pregnancy.

If there was a trophoblastic tumour, there again there is no problem in getting pregnant again. In fact, chemotherapy treatment does not alter fertility or the following pregnancy. It is therefore possible to envisage getting pregnant again after a molar pregnancy. However, it is absolutely necessary to respect the time limit of the monitoring period.

Getting pregnant after a molar pregnancy: are there any precautions to be taken?

When you have had a molar pregnancy, a number of tests will have to be carried out during the pregnancy following the molar pregnancy. A HCG test should therefore be carried out every three months during the pregnancy. These are indeed two periods at risk for the disease. The disease can reappear in a privileged way at these times, which is why extra attention must be paid during these periods.

Molar pregnancy, especially if accompanied by a tumour, can therefore be distressing for the pregnant woman and discouraging. Whether or not a pregnancy is voluntarily or involuntarily terminated is not easy. However, a molar pregnancy has no negative impact on future pregnancies and on the health of the pregnant woman. If regular and serious follow-up is imperative, it is quite possible to become pregnant within six months of follow-up.