What is a molar pregnancy?

You must have heard of the term molar pregnancy, which is a condition common in Asia, Latin America, and the middle east, and less common in Europe and North America. I will answer in this article the most common questions about this condition.

Cherifa Sharaf
Published on:Mar 12th 2023 |Updated on:Mar 10th 2024
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What is Molar pregnancy?

It is a benign tumor from the cells that were supposed to form the placenta, producing cysts that don’t contain a placenta. It happens due to a problem with a fertilized egg, when an egg not containing chromosomes is fertilized or when it is fertilized with two sperms.

How does it happen?

When an egg that doesn’t contain chromosomes is fertilized, then an embryo containing 46 XX chromosomes (only from the father) is produced. In case of a partial molar pregnancy, the embryo will have 69 chromosomes that are either XXX, XXY, or XYY this happens when the egg is fertilized with two sperms.


There are three types of molar pregnancies, complete molar pregnancy is only abnormal cells without a fetus or a placenta. The partial molar pregnancy this one has a deformed fetus, and the last one is the invasive type that originated as partial or complete and it is the most common type of Molar pregnancy.


This condition is detected after having a positive home pregnancy test and visiting the doctor with pregnancy symptoms, such as a missed period, nausea, vomiting, and spotting or bleeding. Upon examination, we find a uterus larger than normal, a misshaped embryo form on the ultrasound, and large cysts over the ovaries, as well as hypertension. In addition, blood tests will show thyroid problems and an increase in pregnancy hormone levels.

It is noteworthy that detecting molar pregnancy by ultrasound is easier when it is a complete molar pregnancy. When it is a partial one and there is an embryo it takes time to discover that the fetus is deformed.


The only treatment available is to terminate the pregnancy and do a dilation and curettage, after doing a thorough check-up to make sure that the patient can undergo such a procedure and is not anemic. After the procedure, all the removed tissue is sent for pathology testing. Continuous monitoring of the pregnancy hormone levels is performed until it reaches zero. In some cases, there is the residue of the cells, and they regrow again. In this case, chemotherapy is required, after doing scans and radiology tests to detect the location of the remaining cells.

After this treatment it is recommended to use contraception for a year, we recommend the pill and not an IUD. It is noteworthy that the chance of this pregnancy happening once again to the same woman is 1 to 1.5%, this is 10 to 15 times more than a woman who didn’t experience this before. If a woman had two molar pregnancies there is a 10 to 25% chance it will happen again, and if she has 3 molar pregnancies there is a 100% chance of it happening again.


There is no way to prevent this from happening, it is a matter of chromosomes, and it's uncontrollable. There is, however, a possibility to test the chromosomes before an ICSI if the couple is willing to undergo such a fertility treatment.


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Cherifa SharafObstetrics & Gynecology Consultant

Consultant of obstetrics, gynecology & Infertility, with years of experience in women’s healthcare. Dr.Cherifa is practicing at Qasr El Eyni Hospital/ Cairo University in addition to several other hospitals and centers in Cairo Egypt. She holds a Ph.D. in medicine from Cairo University in addition to the European Diploma of Operative Gynecology from Clermont-Ferrand, France, and Diploma of Management of Infertility from Antoine Béclère Faculty of Medicine Paris, France. Dr. Cherifa is very passionate about providing the appropriate health care to women and believes the overall health of a woman is key to her reproductive and maternal health. She is a strong believer in the importance of raising women’s awareness and educating them about everything related to health in general and reproductive health in particular.

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