Cleft lip and cleft palate are birth defects that occur when a baby's lip or mouth do not form properly. They happen early during pregnancy. A baby can have a cleft lip, a cleft palate, or both.

A cleft lip happens if the tissue that makes up the lip does not join completely before birth. This causes an opening in the upper lip. The opening can be a small slit or a large opening that goes through the lip into the nose. It can be on one or both sides of the lip or, rarely, in the middle of the lip.

Children with a cleft lip also can have a cleft palate. The roof of the mouth is called the "palate." With a cleft palate, the tissue that makes up the roof of the mouth does not join correctly. Babies may have both the front and back parts of the palate open, or they may have only one part open.

Children with a cleft lip or a cleft palate often have problems with feeding and talking. They also might have ear infections, hearing loss, and problems with their teeth.

Often, surgery can close the lip and palate. Cleft lip surgery is usually done before age 12 months, and cleft palate surgery is done before 18 months. Many children have other complications. They may need additional surgeries, dental and orthodontic care, and speech therapy as they get older. With treatment, most children with clefts do well and lead a healthy life.

Cleft lip with or without cleft palate is among the most common of birth defects. The Centers for Disease Control and Prevention (CDC) estimates that in the United States:

• About 1 in every 1,600 babies is born with cleft lip with cleft palate.
• About 1 in every 2,800 babies is born with cleft lip without cleft palate.
• About 1 in every 1,700 babies is born with cleft palate.

In the earliest days of a baby’s development in the womb, there is normally a split (called a cleft) between the right and left sides of the lip and the roof of the mouth (called the palate). Sometime during the 6^th to 11^th week of pregnancy, this split comes together to form the lips and mouth. If the tissue doesn’t join, it can cause a cleft lip or a cleft palate.

The opening in a cleft lip can be a small slit or a large split that extends from the lip into the nose. The cleft can be on one side or both sides of the lip, or in the middle. The opening in a cleft palate may affect the front, or back, or both parts of the palate.

A baby may be born with only a cleft lip or a cleft palate, but some babies are born with both.

Children with a cleft lip or a cleft palate, depending on the size of the openings, may have problems eating and breathing. As they grow older, they may also have speech and language delays. Children with cleft lip or palate are also more likely to have ear infections, hearing loss, and problems with their teeth.

The lip forms between the fourth and seventh weeks of pregnancy. As a baby develops during pregnancy, body tissue and special cells from each side of the head grow toward the center of the face and join together to make the face. This joining of tissue forms the facial features, like the lips and mouth. A cleft lip happens if the tissue that makes up the lip does not join completely before birth. This results in an opening in the upper lip. The opening in the lip can be a small slit or it can be a large opening that goes through the lip into the nose. A cleft lip can be on one or both sides of the lip or in the middle of the lip, which occurs very rarely. Children with a cleft lip also can have a cleft palate.

The roof of the mouth (palate) is formed between the sixth and ninth weeks of pregnancy. A cleft palate happens if the tissue that makes up the roof of the mouth does not join together completely during pregnancy. For some babies, both the front and back parts of the palate are open. For other babies, only part of the palate is open.

• About 1 in every 1,600 babies is born with cleft lip with cleft palate in the United States.
• About 1 in every 2,800 babies is born with cleft lip without cleft palate in the United States.
• About 1 in every 1,700 babies is born with cleft palate in the United States.

During embryonic development, the right and left maxilla bones come together at the midline to form the upper jaw. At the same time, the muscle and skin overlying these bones join together to form the upper lip. Inside the mouth, the palatine processes of the maxilla bones, along with the horizontal plates of the right and left palatine bones, join together to form the hard palate. If an error occurs in these developmental processes, a birth defect of cleft lip or cleft palate may result.

Cleft lip is a common development defect that affects approximately 1:1000 births, most of which are male. This defect involves a partial or complete failure of the right and left portions of the upper lip to fuse together, leaving a cleft (gap).

A more severe developmental defect is cleft palate, which affects the hard palate. The hard palate is the bony structure that separates the nasal cavity from the oral cavity. It is formed during embryonic development by the midline fusion of the horizontal plates from the right and left palatine bones and the palatine processes of the maxilla bones. Cleft palate affects approximately 1:2500 births and is more common in females. It results from a failure of the two halves of the hard palate to completely come together and fuse at the midline, thus leaving a gap between them. This gap allows for communication between the nasal and oral cavities. In severe cases, the bony gap continues into the anterior upper jaw where the alveolar processes of the maxilla bones also do not properly join together above the front teeth. If this occurs, a cleft lip will also be seen. Because of the communication between the oral and nasal cavities, a cleft palate makes it very difficult for an infant to generate the suckling needed for nursing, thus leaving the infant at risk for malnutrition. Surgical repair is required to correct cleft palate defects.

The most recent research suggests that cleft lip or palate is caused by:

• Genes. A gene defect inherited from one or both parents prevents the lips and mouth from joining during development in the womb.
• Genetic syndromes. A genetic syndrome is a disease that has more than one symptom or defect. It can be caused by a single gene or many genes. Cleft lip or palate are found in more than 400 syndromes, including Waardenburg, Pierre Robin, and Down syndromes. Approximately 30 percent of cleft defects are associated with a genetic syndrome.
• Health and Environment. A mother’s poor health in early pregnancy, or if she drinks alcohol, smokes cigarettes, or takes certain anti-epileptic medications may increase the risk for cleft lip or palate.

The causes of orofacial clefts among most infants are unknown. Some children have a cleft lip or cleft palate because of changes in their genes. Cleft lip and cleft palate are thought to be caused by a combination of genes and other factors, such as things the mother comes in contact with in her environment, or what the mother eats or drinks, or certain medications she uses during pregnancy.

Like the many families of children with birth defects, CDC wants to find out what causes them. Understanding the factors that are more common among babies with a birth defect will help us learn more about the causes. CDC funds the Centers for Birth Defects Research and Prevention, which collaborate on large studies such as the National Birth Defects Prevention Study (NBDPS; births 1997-2011) and the Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS; began with births in 2014), to understand the causes of and risks for birth defects, including orofacial clefts.

Recently, CDC reported on important findings from research studies about some factors that increase the chance of having a baby with an orofacial cleft:

• Smoking―Women who smoke during pregnancy are more likely to have a baby with an orofacial cleft than women who do not smoke.
• Diabetes―Women with diabetes diagnosed before pregnancy have an increased risk of having a child with a cleft lip with or without cleft palate, compared to women who did not have diabetes.
• Use of certain medicines―Women who used certain medicines to treat epilepsy, such as topiramate or valproic acid, during the first trimester (the first 3 months) of pregnancy have an increased risk of having a baby with cleft lip with or without cleft palate, compared to women who didn’t take these medicines.

CDC continues to study birth defects, such as cleft lip and cleft palate, and how to prevent them. If you are pregnant or thinking about becoming pregnant, talk with your doctor about ways to increase your chances of having a healthy baby.

A cleft lip may be diagnosed in pregnancy during a routine ultrasound. It will usually be visible during a baby’s first examination, although some types of cleft palate aren’t easily visible and might not be diagnosed until later in life.

Treatment for children with cleft lip or palate depends on the size of the cleft, the child’s age and needs, and whether there are additional problems related to a genetic syndrome. A child with cleft lip or palate is often referred to a team of experts that may include an otolaryngologist (ear, nose, and throat doctor), plastic surgeon, oral surgeon, speech pathologist, pediatric dentist, orthodontist, audiologist, pediatrician, nutritionist, and psychologist/social worker. Because cleft lip and palate are so often part of genetic syndromes, a thorough medical examination and genetic counseling is recommended for children and their parents to find out whether their future children may be affected.

Surgery is often used to close the lip and palate. Cleft lip surgery is usually done before a baby’s first birthday, and cleft palate surgery is done before 18 months. If there are other problems as they get older, a child may need additional surgeries, dental and orthodontic care, and speech therapy. With treatment, most children with cleft lip or palate do well and lead a healthy life.

• Ask for advice, especially if your baby has problems nursing or drinking from a bottle. There are many ways to overcome feeding challenges.
• Ask questions. Talk to the people who are treating your baby and ask them to explain what you don’t understand.
• Ask for support from family, friends, and other parents of children with cleft lip and palate.