Molar pregnancy or in medical term known as hydatidiform mole is a significantly uncommon complication of fertilization. In the United States there is a 0.6-1.1 per 1000 of H-mole cases are known (Ho 2003, as mentioned by Masterson, Chan and Bluhm in 2009). It is under the big category of gestational trophoblastic diseases and can either be a complete mole, or a partial mole. On one hand, in a complete molar pregnancy, per ultrasound there can be seen a distinctive snowstorm appearance with hydropic villi and intrauterine hemorrhage.
When we say hydropic villi these are irregularly enlarged chorionic villi which contains fluids typical of a hydatidiform mole. Chorionic villi in a normal pregnancy, a normal pregnancy are tiny and finger-like shapes that originates from the placenta. Its function is to provide maximum contact with the maternal blood for fetal nutrition. So, if we see this in molar pregnancy, these structures are irregularly enlarged and diffused forming a mass of multiple vesicles. There is definitely no evidence of a fetus. In addition to that, the ovaries in a complete mole are typically containing multiple large theca-lutein cysts because of overstimulation of the of the ovaries by the beta human chorionic gonadotropin hormone (Benson, Genest, Bernstein, Soto-Wright, Goldstein and Berkowitz 2000 as mentioned by Caliere, Ermito, Dinatale and Pedata 2009).
On the other hand, in a partial mole the fetus may still be present, which makes it hard to determine via ultrasound. However, the fetus may be seen as a triploid, a fetal abnormality with 69 chromosomes instead of the normal 46 chromosomes. The enlarged villi in partial mole is less distinguishable and show minimal abnormalities, with visible scattered normal chorionic villi. The fetus has a small placenta, and growth restricted and is followed by early neonatal death.
The most defining risk factor of molar pregnancy is the extreme age of the mother, that is if the mother is less than 20 years old and more than 40 years of age, that can be a risk factor. However, because 20-40 years old are child bearing age, most of the pregnancies happen within this range. Also, when a mother has a history of the trophoblastic disease, this can also be an additional predisposing factor to having a molar pregnancy. Other risk factors are not limited to the use of oral contraceptive, blood groups of the mother (A or AB blood groups), lifestyle of the mother such as smoking and alcohol.
So, what really happened?
It has something to do with the abnormalities of the egg cells and sperm cells itself. For complete moles, for instance, an enucleated egg (an egg without a nucleus) is being fertilized by two sperm cells or a haploid sperm and in a partial mole, two sperms fertilize a haploid egg cell of the mother. So, well, maybe sometimes in nature there are two winners, however it results in an unlikely way.
What are the characteristic signs and symptoms?
Molar pregnancy usually presents in the first three months of having the signs and symptoms of pregnancy. Findings can include missed period, vaginal bleeding, size of the uterus that may be inappropriate in size based on the calculated pregnancy date, so it can either be too large or too small, and an excessive amount of the human chorionic gonadotropin hormone which results in extreme nausea and vomiting among affected women. It is said that the appearance of the vaginal bleeding is this condition is “prune juice” in appearance (Ghassemzadeh and Kang, 2017).
How is it diagnosed?
Determination of the hydatidiform mole is based on an array of clinical characteristics. As mentioned previously it includes unusual vaginal bleeding, inappropriate enlargement of the uterus, pain experienced because of the large cysts accompanied by vaginal discharges of grape-like vesicles, exaggerated nausea and vomiting, hyperthyroidism and preeclampsia.
Diagnostic examinations such as ultrasound can ascertain molar pregnancy before 12 weeks and can be seen in the monitor as fine vascular or honeycomb appearance. If a molar pregnancy is diagnosed, the next step is to have a chest x-ray to determine its spread to other parts of the body. Of the 3,000 women with a partial mole, 0.1% had a choriocarcinoma, a fast-developing cancer that is seen in the uterus of the woman, but persistent malignant complications are more associated with the complete molar pregnancy (Cavaliere, Ermito, Dinatale and Pedata, 2009).
How is it managed?
If in the emergency room, if the patient is showing signs of increased blood pressure and respiratory distress, then the patient has to be stabilized. Once the patient is stable, the obstetric would probably have to order dilation and curettage (D and C) preferably suction curettage to minimize the risk of spread of abnormal tissues to other parts of the body through the maternal circulation. However, for women who are greater than 40, since they are pass their childbearing stage, a hysterectomy (or removal of the uterus) might be necessary. If removal of the molar pregnancy is done, and hCG levels are still high then malignancy work up must be considered that will somehow necessitate chemotherapy.
Author: Sarah Catina RN
Cavaliere, A.; Ermito, S.; Dinatale, A. & Pedata, R. (2009). Management of molar pregnancy. J Prenata Med. 3(1): 15-17 Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279094/
Masterson, L.; Chan, S.B. & Bluhm, B (2009). Molar pregnancy in the emergency department. West J Emerg Med. 10(4):295-296. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2791738/
Ghassemzadeh, S & Kang, M. (2017). Hydatidiform mole. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK459155/