Cleft lip and palate - Causes 

A cleft lip or palate occurs when the structures that form the upper lip or palate fail to fuse together properly when a baby is developing in the womb.

The causes may be genetic (internal) or environmental (external), although it is most often thought to be a combination of these factors. In most cases of cleft lip or palate, there is no recognisable cause.

Inherited genes

Research indicates that the genes a child inherits from their parents can make them more vulnerable to developing a cleft lip or palate. Researchers have identified a number of genes that may be responsible.

In some cases, there is a family history of clefts, although most children of parents with clefts will not develop clefts themselves.

Environmental risk factors

A number of environmental risk factors have been identified that may increase a child’s chance of being born with a cleft lip or palate. These are outlined below.

Maternal smoking

A mother who smokes during pregnancy increases her baby’s chance of being born with a cleft. The risks from passive smoking are not fully known, but it is a good idea to avoid breathing in high levels of second-hand smoke.

Maternal alcohol consumption

Some studies have shown a link between a mother’s alcohol consumption during pregnancy and the development of a cleft lip and palate in her baby.

Maternal obesity

Mothers who are obese have a higher chance of their child being born with a cleft. Poor nutrition during pregnancy can also increase the risk.

Lack of folic acid during pregnancy

All pregnant women are advised to take a daily supplement of folic acid during the first four months of pregnancy. Folic acid helps reduce the possibility of birth defects, such as spina bifida (a series of birth defects that affect the development of the spine and nervous system) and cleft palate.

Medications during pregnancy

It has been suggested that some medications taken during pregnancy may increase the risk of cleft lip and palate. These include:

• methotrexate, a medicine that is used to treat cancer, arthritis and psoriasis
• isotretinoin, a medicine that is used to treat acne
• anti-seizure medicine

Speak to your GP or midwife if you are concerned about any of the medications you are taking during your pregnancy.

Pierre Robin syndrome

Pierre Robin syndrome is a rare condition where a baby is born with an abnormally small lower jaw that causes the tongue to fall backwards in their throat (glossoptosis). This can result in obstruction and breathing difficulties.

Most infants with Pierre Robin syndrome will also have a cleft palate, which can usually be repaired with surgery. However, sometimes the surgery has to be delayed if there are continuing issues with airway obstruction.