A portion of children with cerebral palsy have congenital cleft lip, which can be caused by the following: In the fourth week of embryonic development, a middle nasal prominence, two lateral nasal prominences and maxillary and mandibular prominences from the first gill arch are formed around the mouth area. Later, both maxillary prominences fuse with the middle nasal prominence to form the upper lip. If fusion is impaired, a cleft lip is formed, or if neither side is fused, a bilateral cleft lip is formed.
The exact cause and pathogenesis of developmental and fusion disorders are not yet fully understood. According to a large number of experimental studies and epidemiological findings, it may be due to the influence of multiple factors rather than a single one. Broadly speaking, it can be divided into two aspects: genetic factors and environmental factors, and is related to nutrition, genetics, infection, endocrine and other factors.
Genetic factors: Patients with cleft lip can be found to have similar deformities in their direct or collateral relatives, so it is believed that cleft lip deformity has some relationship with genetics. Epidemiological investigations have shown that the incidence of cleft lip in the offspring of those with cleft lip in their direct relatives is higher than that of those without cleft lip in their relatives. Genetic studies have also concluded that cleft lip is a polygenic hereditary disease.
2, environmental factors: mainly refers to the environment in which the embryo grows and develops, the entire physiological state of the mother constitutes the environmental conditions for the development of the embryo. Therefore, in the first trimester, when the maternal physiological state is attacked or disturbed, it may affect the growth and development of the embryo’s jaw and face.
(1) Nutritional deficiencies: In experimental animal studies, it was found that mice deficient in food components such as vitamin A, B2 and folic acid can produce malformations such as cleft lip, while it is not very clear whether congenital malformations can also occur in humans due to deficiencies of such substances. Therefore, nutritional deficiency in early gestation may be one of the triggers for the development.
(2) Infection and injury: If the mother suffers some kind of injury in the early stage of pregnancy, especially the injury that can cause the uterus and its adjacent parts, such as improper incomplete abortion or unscientific drug abortion, can affect the development of the embryo and cause malformation. Maternal viral infections such as rubella can also affect the development of the embryo and become a possible cause of cleft lip.
(3) Endocrine influences: Babies born after hormonal treatment for a disease in early pregnancy have some kind of congenital malformation. In addition, in the investigation of the family history of children with cleft lip, it was also found that some mothers had various obvious traumatic factors in early pregnancy, and it is inferred that this may lead to stress reactions, resulting in increased secretion of adrenocorticotropic hormones in the body and inducing congenital malformations.
(4) Drug factors: Most drugs can enter the embryo through the placenta after entering the mother’s body. Some drugs may affect the development of the embryo and cause malformation, currently known anti-tumor drugs (such as cyclophosphamide, methotrexate, etc.), anticonvulsant drugs (phenytoin sodium), antihistamines and treatment of pregnancy vomiting Minkajin and some sleeping drugs (such as thalidomide) can cause fetal malformation.
(5) Physical injury: For example, frequent exposure to radiation or microwaves during fetal development may affect the growth and development of the fetus and become a possible cause of cleft lip.
(6) Tobacco and alcohol factors: Heavy smoking and alcohol abuse in early pregnancy have a higher incidence of cleft lip in children than in women without tobacco and alcohol habits, and are therefore one of the possible factors leading to cleft lip in the fetus.