By Dr Ananya Mandal, MD
Cleft lip or palate affects one in 700 babies in the United States and the United Kingdom. The reason for this defect lies in defects normal development of the face within the mother’s womb.
The exact cause for this defect is often unknown.
Cleft lip and palate and cultures
In many cultures worldwide a cleft lip or palate is thought to represent a sign of evil or wrong-doing on the part of the family.
Many parents may thus be affected with severe guilt. It is important that they are reassured that they did nothing wrong to cause the child’s birth defect. (1-7)
Cleft lip and palate pathophysiology
Normally the tissues of the face develop from either side and fuse in the middle. This takes place within the first 30 to 60 days of pregnancy.
This is true for the upper lip and the palate roof of the moth as well. The lip has usually formed by 5-6 weeks of pregnancy and the palate has formed by 10 weeks.
When this union or fusion does not take place normally a separation may form in the upper lip and or the palate. A cleft in the upper lip and palate may often coexist.
The exact reason for this non-fusion is unknown. Since the lip and the palate develop at different times, they may exist alone as well.
Inherited cleft lip and palate
In some babies the condition may be inherited. In their families there may be multiple instances of similar cleft lips and palates.
Cleft lip and palate may be the only abnormality or birth defect in some babies. In 13 to 30% infants the cleft lip and/or palate may be a part of a genetic birth defect syndrome.
In these babies there may be other symptoms and genetic diseases at birth. For example, Pierre Robin syndrome is a rare condition where the baby is born with a small lower jaw that causes the tongue to fall backwards in their throat. This leads to breathing difficulties. These babies may also have a cleft palate, which can usually be repaired with surgery.
Who does cleft lip and palate affect?
Cleft lip and/or palate is seen more commonly among people of Asian descent and those belonging to some American Indian families.
Male babies are more often affected than female babies. African American babies are seldom affected.
Possible causes of cleft lip and palate
Some experts believe there may be nutritional deficiencies or side effects from medications that may lead to increased risk of cleft lip and palate.
Genetic inheritance of cleft lip and palate
In genetic inheritance of the condition either parent can pass on a gene or genes that cause clefts. Researchers have identified a number of genes that may be responsible.
It is found that children of a parent with a cleft have a 4 to 6 percent chance of being born with clefts. If a child is born with clefts but neither parent has a cleft, the risk of clefts in a biological sibling is 2 to 8 percent.
The risk of clefts in biological siblings and future children increases to 15 to 20% if parents as well as the first two children have clefts.
Children who have no family history of clefts are at 0.14% risk of being born with a cleft lip and/or palate.
Environmental causes of cleft lip and palate
Environmental causes include poor early pregnancy health and exposure to various toxins during pregnancy. Exposure to alcohol and tobacco are linked to risk of babies born with cleft lip and/or palate.
Mothers who are taking medications for epilepsy may also be at a higher risk of giving birth to babies with a cleft lip and/or palate. This includes drugs like:
- sodium valproate,
- benzodiazepines etc.
Those taking corticosteroids, methotrexate (for psoriasis, arthritis or cancers) or isotretinoin (for acne) are also at risk.
Other risks for cleft lip and palate
Deficiency of B vitamins and folic acid in maternal diet is another commonly associated cause of cleft lip and palate in the new born.
Parents who are older than usual at the time of birth of their baby are at higher risk of having children with cleft lip and or palate.
A viral infection during pregnancy may also be associated with cleft lip and palate. Mothers who are obese have a higher chance of their child being born with a cleft.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Jul 18, 2012