What is hydatidiform mole and what adverse effects does it have on the health of the fetus and the mother?

The most feared thing for pregnant women is hydatidiform mole, which is one of the most important factors causing miscarriage in pregnant women. At the same time, hydatidiform mole has a high recurrence rate. To put it bluntly, if a woman has had hydatidiform mole, then the probability of having hydatidiform mole again in the next pregnancy is very high. It can be said that hydatidiform mole is an abnormal pregnancy with great harm. Therefore, what many women fear most is hydatidiform mole.

So what is hydatidiform mole? What adverse effects does hydatidiform mole have on the health of the fetus and the mother? How does hydatidiform mole come about? What methods can be used to prevent hydatidiform mole in daily life?

The microvessels in the villous matrix disappear, resulting in accumulation of fluid in the villous matrix and formation of bubbles of varying sizes that resemble grapes, hence the name hydatidiform mole. There are complete and partial hydatidiform moles, and most of them are complete hydatidiform mole. The clinical diagnosis of hydatidiform mole refers to complete hydatidiform mole; partial hydatidiform mole accompanied by placental tissue and/or fetus is called partial hydatidiform mole. In the tissues of spontaneous abortion, 40% of patients were found to have certain vesicular degeneration, but they were not diagnosed as hydatidiform mole.

Hydatidiform mole is divided into two categories: ① Complete hydatidiform mole: all the placental villi are affected, there is no fetus and its appendages, and the uterine cavity is filled with blisters; ② Partial hydatidiform mole: only part of the placental villi undergo blister-like degeneration, and there are still living or dead embryos in the uterine cavity.

Macroscopic observation: Grape-like blisters of varying sizes, with thin, transparent walls, containing viscous liquid, and filled with blood and blood clots. Because trophoblastic cells produce a large amount of human chorionic gonadotropin (HCG), which stimulates the ovaries to form lutein cysts, the cysts have a smooth surface, yellow color, thin walls, multi-chamber cross-section, and clear cystic fluid.

Cause:

Cytogenetic studies have shown that most partial hydatidiform moles are of male origin, with an extra set of paternal chromosomes. Most PHMs arise from fertilization of an egg by two sperm. Occasionally, PHM may result from fertilization of a single egg with a diploid sperm. The karyotype of PHM is 69XXX, 69XXY, 69XYY. Complete hydatidiform mole is generally diploid. According to the genetic origin, it can be divided into complete hydatidiform mole of paternal origin (androgenetic CHM, AnCHM) in which both sets of chromosomes come from the father and complete hydatidiform mole of biparental origin (biparental complement hydatidiform mole, BiCHM) in which both sets of chromosomes come from the father and the mother respectively. Among the complete hydatidiform mole of paternal origin, 75% to 80% are formed by the self-replication of the DNA in the nucleus after fertilization of a sperm (23, X) and an empty egg, and the karyotype is 46, XX. Another 20% to 25% of the complete hydatidiform mole of paternal origin has a karyotype of 46XY, which is formed by the simultaneous fertilization of an empty egg and two sperms. Although the chromosomal components of complete hydatidiform mole are all paternal, the mitochondrial DNA in its cytoplasm is maternal. BiCHM represents a unique type of HM, accounting for approximately 20% of complete hydatidiform moles and is often associated with familial recurrent hydatidiform mole. Two or more individuals in these families are complicated by recurrent molar pregnancies. The inheritance pattern of susceptibility to molar pregnancy in affected family members suggests an autosomal recessive inheritance, and the fact that the same patients developed molar pregnancies again after marriage with different sexual partners suggests that these women may have genetic defects that affect the function of the egg. BiCHM is rare. In addition to familial disease, some sporadic women with repeated HM have recently been confirmed to have BiCHM. These women may represent individuals with the same disease situation. BiCHM carries the chromosome genomes of both the father and the mother. Although BiCHM and AnCHM have different gene origins, they have the same histopathological characteristics and consistent expression patterns. There are many forms of fertilization in hydatidiform mole, resulting in different genetic types, and the exact pathogenesis is still unclear. HM with different genetic backgrounds has different pregnancy outcomes and prognoses. Therefore, it is very important to distinguish hydatidiform mole with different genetic backgrounds, clarify the pathogenesis of HM, and make an accurate diagnosis of HM to guide clinical treatment.

Because hydatidiform mole is very harmful to women's health, I would like to remind all expectant mothers to go for a check-up during pregnancy so that they can detect abnormal pregnancies such as hydatidiform mole as early as possible and reduce the harm of pregnancy to women's bodies.