What Causes Cleft Lip and Palate?

Cleft lip and palate is a congenital disorder. Currently, approximately one in every 1,000 children is born with a cleft lip—a condition that not only delivers a significant emotional blow to families but also profoundly impacts the child’s future development. So, what causes cleft lip and palate? Below, we provide answers to this question.

Causes of Cleft Lip and Palate

1. Genetic Factors

If the mother has a cleft lip or palate, the risk of her offspring developing the condition rises to as high as 15%; if the father is affected, the risk is approximately 5%. Research indicates that after having one child with a severe cleft lip and/or palate, the chance of a second child being similarly affected is about 5%; for milder cases, the recurrence risk drops to 3%. Additionally, offspring of consanguineous marriages face an even higher incidence rate.

2. Maternal Illness During Pregnancy

Clinical data suggest that certain maternal illnesses during pregnancy are major contributors to congenital cleft lip and palate. For instance, common colds—particularly during the first trimester—can pose significant risks. Facial structures begin forming in the fourth week of embryonic development, palatal development initiates in the fifth week, and complete fusion of all palatal components occurs by the twelfth week. Thus, maternal illness during this critical period may disrupt normal palatal development in the fetus.

3. Medication Exposure

Pregnant women—especially during early gestation—must avoid taking medications indiscriminately, as numerous drugs can adversely affect fetal growth and development. Well-documented teratogens associated with cleft lip include hormonal agents, antiepileptic drugs, and sedatives. Certain medications readily cross the placental barrier and interfere with embryogenesis—for example, hypnotics, antihistamines, phenytoin, corticosteroids, and cyclophosphamide—all of which carry documented risks of causing fetal malformations.

4. Environmental Pollution

Exposure during early pregnancy to chemical agents—including pesticides—or toxic substances, excessive radiation, or prolonged computer use may increase the risk of congenital cleft lip and palate. Consequently, experts recommend limiting extended computer work during pregnancy. Moreover, smoking, alcohol consumption, or intake of alcoholic beverages—including habitual heavy drinking—during pregnancy can inadvertently harm the developing fetus.

The above outlines the primary etiological factors underlying cleft lip and palate. We hope this information proves helpful to you.