What causes a hydatidiform mole?
Jun 02, 2021
Source: Cainiu Health
Dr. Kong Xiang
Introduction
1. Ovarian factors: Animal experiments have demonstrated that oophorectomy during early pregnancy can lead to hydropic degeneration of the placenta.
2. Nutritional deficiencies: Folate, beta-carotene, vitamin A, zinc, and other trace elements may be deficient in pregnant women.
3. Racial factors: Differences in gestational trophoblastic disease (GTD) incidence among racial groups have drawn expert attention; additionally, a high number of pregnancies and frequent use of oral contraceptives are associated risk factors.
Molar pregnancy is an abnormal form of gestation—essentially a disease. Specifically, it is a disorder originating from trophoblastic cells at the placental site, occurring during a woman’s pregnancy and classified under gestational trophoblastic disease (GTD). In molar pregnancy, no viable fetus develops within the uterine cavity; instead, the uterus contains only grape-like clusters of cystic, fluid-filled vesicles—hence the term “molar pregnancy” (literally “grape mole”). So, what causes molar pregnancy? The following explains this question.
What Causes Molar Pregnancy?
1. Ovarian Factors
Animal experiments have demonstrated that ovariectomy performed early in pregnancy leads to hydropic (cystic) degeneration of the placenta. Thus, experts believe that molar pregnancy is strongly associated with impaired ovarian function and insufficient estrogen secretion. Additionally, proto-oncogenes and tumor-suppressor genes regulate cellular growth and differentiation. Activation and overexpression of proto-oncogenes, as well as mutations or inactivation of tumor-suppressor genes, are implicated in tumorigenesis—including gestational trophoblastic neoplasia.
2. Nutritional Deficiencies
Molar pregnancy occurs more frequently in rice-consuming countries, suggesting a potential link to nutrition. Clinical studies indicate that women deficient in folic acid, beta-carotene, vitamin A, zinc, and other trace elements during pregnancy face a higher risk of developing molar pregnancy. Therefore, nutritional deficiencies appear to contribute significantly to its pathogenesis. Moreover, chromosomal abnormalities have also been identified as a major predisposing factor.
3. Racial Factors
Significant inter-racial differences in molar pregnancy incidence have drawn expert attention. For instance, reported incidence among Black women in the United States is approximately half that observed in other racial groups. In Singapore, Eurasian women exhibit a molar pregnancy incidence twice as high as that among Chinese, Indian, and Malay women. Furthermore, frequent pregnancies and prolonged use of oral contraceptives may also increase susceptibility to molar pregnancy.
The above outlines the primary etiological factors associated with molar pregnancy. We hope this information proves helpful.
