In multiple pregnancies, perinatal mortality and twin diseases are more common, and there is also a tendency to premature birth. Approximately 12% of prematurely born babies are the result of such pregnancies, and the twins at birth are smaller and lighter. Low weight and premature birth are the basis for assigning such children to the high-risk group: approximately 10-20% of them die compared with 2% of the mortality of children from singleton pregnancies..
"Paper fetus"
Perhaps the incidence of pregnancies is significantly higher than they are actually born. Many twins die before birth: some studies show that only 29% of women, pregnant with twins, give birth to two children. Термин «The term “missing twin”» refers to the death of one fetus.This «disappearance» occurs in the morning or as a result of the formation of a paper fetus (papyrus fruit) (fetus papyraceus).
Twin Transfusion Syndrome
Twin Transfusion Syndrome Twin Transfusion Syndrome .
Conjoined twins
Separation of the zygote in the late stages of development can lead to abnormal or incomplete splitting of the axial section of the germinal disk. Such not quite isolated germinal discs cause the formation of conjoined (Siamese) twins. According to the nature and degree of join, they are divided into thoracopagi (pagos - attached), , пигопагов и краниопагов. Sometimes monozygotic twins can be joined with one another only by skin or liver bridges. The type of fusion of the twins depends on the time of occurrence and the degree of anomalies of the primary nodule and primary strip. Impaired gene expression can also lead to the formation of conjoined twins. Many fused twins survived, including the most famous pair of Chang and Eng, who were fused in the abdomen and came to England and the United States for exhibitions in the mid-1800s. Having settled in North Carolina, they were engaged in agriculture and, together with two spouses, became the fathers of 21 children..
