Molar pregnancy: symptoms, causes and treatment

Grossesse môlaire : symptômes, causes et traitement

This is a rare but potentially serious phenomenon that occurs during pregnancy. It is characterized by abnormal growth of placental tissue, which can lead to complications for both mother and fetus.

Signs can include vaginal bleeding, nausea and vomiting, high blood pressure, and swelling and pain in the abdomen. Elia takes a look at the subject: in this article, find out all you need to know about molar pregnancy, the related symptoms, the causes and, above all, possible treatment.

What is molar pregnancy?

As previously introduced, molar pregnancy is an anomaly that manifests itself through abnormal development of the placenta. More precisely, it is a gestational trophoblastic disease involving a pregnancy with abnormal growth of the fertilized egg or placental tissue.

It causes nausea, vomiting, vaginal bleeding, high blood pressure, a rapidly enlarging uterus and can lead to serious complications. It is treated by dilatation and curettage, and sometimes chemotherapy. Either there is an embryo (partial molar pregnancy), but it is not viable, or there is no embryo at all (complete molar pregnancy).

Molar pregnancies seem to be more frequent in women under 17 or over 35, and in Asian countries, for reasons that remain unclear.

Partial molar pregnancy

There are two types of molar pregnancy: partial and total mole. In partial hydatidiform mole, the egg is fertilized by two sperm cells or one abnormal sperm cell, resulting in abnormal growth of the placenta and fetus. The embryo is present, but not viable, as the placenta develops abnormally.

Complete molar pregnancy

In the case of complete mole (or complete hydatidiform mole), fertilization does take place, but the ovum is anucleate (without a nucleus and therefore without genetic material) and one or two spermatozoa are haploid (with only one copy of each chromosome). The product of this pregnancy contains no embryo, only the placenta. The placenta develops in the form of cysts (described as "bunches of grapes").

What are the symptoms of a molar pregnancy?

Signs may vary from one woman to another, but some common ones can be observed. The most common symptoms include abnormal vaginal bleeding, severenausea and vomiting, high blood pressure, enlargement of the uterus and abdominal swelling or pain.

Other less common symptoms may include anemia, vitamin D deficiencyhyperthyroidism or signs of gestational trophoblast cancer.

It's important to remember that these can resemble those of a normal pregnancy! So it's essential to consult a doctor if you have any signs to worry about. Early diagnosis of pregnancy is essential to ensure rapid and effective treatment of this anomaly.

What causes molar pregnancy?

Molar pregnancy is a rare pregnancy anomaly caused by chromosomal maldistribution at the time of fertilization.

It would appear that several factors may be responsible for this anomaly:

  • The mother's age: an early pregnancy (before 16 or 17) or a later one (after 35 or 40) may increase the risk of developing it;
  • A previous miscarriage (or several);
  • Vitamin A deficiency may also lead to complete hydatidiform mole;
  • Stimulation with Clomiphene citrate, i.e. ovarian stimulation for women undergoing MAP, may also increase the risk.

How is hydatidiform mole diagnosed?

This rare complication can be diagnosed in several ways.

In the first instance, the doctor may suspect it based on clinical aspects, such as an abnormally developed uterus or symptoms such as abnormal vaginal bleeding. A pregnancy test may also be performed, and in the case of a molar pregnancy, the pregnancy test is positive, but no fetal movement or pulse is detected.

Pelvic endovaginal ultrasound remains the most accurate method for this diagnosis. This examination uses sound waves to create images of the pelvic organs and can identify the presence of an abnormal mass in the uterus.

Diagnosis can therefore be made using a combination of clinical tests, blood tests and medical imaging, and it is important to make the diagnosis quickly to reduce the risk of serious complications.

hCG hormone levels

A blood test can be performed to measure levels of the hormone hCG, a hormone normally secreted at the start of pregnancy.

In the case of a molar pregnancy, hCG levels are abnormally high. However, these tests are not sufficient to confirm the pregnancy definitively, and must be combined with other analyses.

How is complete or partial molar pregnancy treated?

Treatment of molar pregnancy is the same for both partial and complete pregnancies. In both cases, treatment consists of rapid and complete surgical evacuation of the mole to prevent complications. In other words, Voluntary Interruption of Pregnancy by curettage and aspiration. Depending on severity, chemotherapy may be necessary, particularly if the mole has affected other organs.

After treatment of a molar pregnancy, close follow-up is recommended to watch for any signs of relapse. It is also advisable to wait at least a year before trying to conceive a baby again.

What are the complications of hydatidiform mole?

Several complications can arise:

  • Hemorrhage, due to abnormal growth of the placenta and rupture of the blood vessels;
  • A risk of cancer, also known as gestational cancer or choriocarcinoma;
  • A risk of miscarriage;
  • pre-eclampsia syndrome, characterized by high blood pressure;
  • The development of cysts in the ovaries;
  • Difficulty getting pregnant again.

Is it possible to become pregnant after a molar pregnancy?

It is quite possible to become pregnant again, but this depends on the severity of the mole. In most cases, a woman who has had a molar pregnancy can try to conceive again after six months to a year .

Given the increased risk of developing another molar pregnancy, it is advisable to consult your doctor to discuss the risks and options for ensuring an optimal pregnancy under the right conditions.

Molar pregnancy FAQ

How long is the hospital stay for a curettage for a molar pregnancy?

The length of hospitalization varies according to several factors, including the severity of the mole and the patient's reaction to the procedure. In general, hospitalization lasts a maximum of one day. After the curettage, the patient is monitored for a few hours to ensure that there are no complications, such as excessive bleeding or infection. If all goes well, the patient can go home the same day or the day after the procedure.

At what stage of pregnancy can a molar pregnancy be detected?

There are several ways to diagnose a molar pregnancy. Generally, the first sign is an elevated level of the hormone human chorionic gonadotropin (hCG), detected by a blood test. This level can be measured at the first signs of pregnancy. Other signs include an abnormally large uterus, abnormal vaginal bleeding, absence of fetal heartbeat or ultrasound findings indicative of hydatidiform mole. It can therefore be detected as early as the first pregnancy ultrasound, often performed between the sixth and twelfth weeks of pregnancy.

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The information contained in the articles on is general information only. Although reviewed by health professionals, this information is not error-free, does not constitute health advice or consultation, and is not intended to provide a diagnosis or suggest a course of treatment. Under no circumstances may this information be used as a substitute for medical advice or consultation with a healthcare professional. If you have any questions, please consult your doctor.