On an average, one in every 700 children worldwide is born with a cleft. It is the fourth most common birth defect, and the first most common facial birth defect.
Genetic factors: Sometimes a cleft can be genetic. The risk may be higher for children whose sibling(s) or parents have a cleft or who have a history of cleft in their families. Consanguineous marriage (marriage between close relatives or cousins) can also be a cause.
Environmental factors: Not all birth deformities are hereditary. Even in the absence of any genetic factors, there are some external factors that may result in cleft formation.
1. Maternal exposure to smoking, use of tobacco, illicit drugs or alcohol consumption during pregnancy is extremely harmful for the developing baby.
2. Certain medications like steroids and others as those prescribed for Seizures, Cancer, Arthritis, Tuberculosis etc have been linked to the development of a cleft. Harmful medications and erratic dosages taken without consulting a doctor may have detrimental effects on the foetus. Women taking oral contraceptive pills unaware of their pregnancy may also contribute to clefting.
3. Studies have shown cleft is also related to advanced maternal age and also to some hormone deficiencies and dietary deficiencies namely that of folic acid, iron, iodine and zinc.
4. Cleft lip and cleft palate may also occur as a result of exposure to viruses or infectious diseases like measles while the fetus is developing in the womb.
5. Exposure to certain harmful chemicals, vapours, pesticides, gun powder fumes, nuclear radiation, X-rays, gamma rays or dangerous reagents like in industrial workplaces have dangerous effects on the genetic composition and growth of the developing baby.