A peculiar phenomenon is that hydatidiform moles occur more frequently in women from Eastern countries, particularly in Southeast Asia and Taiwan. Physicians indicate that according to a research report by the Taiwan Medical Association, the incidence rate in Taiwan averages approximately 0.3%, which is 3 to 5 times higher than in Western countries. However, the exact reason for this disparity remains unclear.
Beware of Hydatidiform Mole Progressing to Choriocarcinoma
During pregnancy, abnormal division and proliferation of trophoblastic cells on the placental villi form vesicles of varying sizes. Small vesicles are barely visible, while larger ones resemble fingers. These vesicles are connected by thin stalks, forming clusters resembling grapes—hence the name hydatidiform mole, also known as vesicular mole.
With advances in medical technology, hydatidiform mole is now considered a rare gynecological condition. As an early stage of gestational trophoblastic disease, approximately 20% of cases may progress to choriocarcinoma. Delayed diagnosis carries significant risks, including massive hemorrhage, uterine infection, and potential sepsis, which can be life-threatening.The exact cause of hydatidiform mole (molar pregnancy) remains unclear. It is known to result from abnormal development of the chorionic villi, involving varying degrees of trophoblastic proliferation and villous matrix edema. The chorionic villi transform into clusters of clear fluid-filled sacs, typically aggregating into masses suspended by a slender stalk. These sacs range in size from barely visible to several centimeters in diameter.
Medical statistics indicate a hydatidiform mole occurs in approximately one in every thousand pregnancies. Women over 45 face a tenfold higher risk than younger women. Common symptoms include abnormal bleeding, uterine enlargement (appearing five months pregnant at three months gestation), absence of fetal movement, severe morning sickness (nausea and vomiting), hyperthyroidism, and preeclampsia.
Most molar pregnancies are benign and can be cleared from the uterus using vacuum aspiration and uterine contractions. However, in cases of complete mole, approximately 20% of patients develop choriocarcinoma, a malignant tumor that can metastasize to organs such as the liver, kidneys, lungs, brain, and vagina.
What are the cancer prevention measures for hydatidiform moles?
I. Prophylactic Chemotherapy
This primarily prevents malignant transformation of the mole. Therefore, prophylactic chemotherapy should be administered to women over 40 years old, those with difficulty in regular follow-up, or those clinically assessed as having a higher risk of malignancy. Prophylactic chemotherapy typically involves a single drug for one course, but the dosage should be equivalent to that used for treating malignant trophoblastic tumors and should not be reduced.
II. Regular Follow-up
Post-molar pregnancy follow-up is critical for early detection of malignant transformation and timely intervention. Following curettage, weekly urine hCG testing is required until hCG becomes negative or concentrated urine hCG turns negative, and radioimmunoassay levels return to normal. Subsequently, blood or urine testing should be conducted every 2 weeks or monthly.
Follow-up should continue monthly or bimonthly for three months. After six months or one year, transition to semi-annual or annual check-ups. Monitoring should persist for at least three years, ideally extending to 10–15 years. If clinical symptoms arise during follow-up, additional necessary tests should be conducted promptly. After molar pregnancy treatment, contraception should be maintained for at least 1–2 years to avoid difficulty distinguishing between recurrent pregnancy and malignant transformation.
Further Reading: 3 High-Risk Groups to Note
【Maternal Age】Pregnant women under 20 or over 40 are at higher risk due to immature or unhealthy eggs, which may result in "empty sac pregnancies" and subsequently molar pregnancies.
【Poor Nutrition】Pregnant women in underdeveloped regions face higher pregnancy risks due to malnutrition or lack of timely prenatal care, making them more susceptible to molar pregnancies than the general population.