A cleft is a gap or split in the upper lip, the roof of the mouth (palate), or both. It happens when facial structures don’t fully fuse together during early pregnancy. About 1 in 1,000 babies in the United States is born with a cleft lip, a cleft palate, or a combination of the two, making it one of the most common birth differences.
Clefts range from a small notch in the lip to a full opening that extends from the lip through the gum and into the roof of the mouth. They’re treatable with surgery, usually in the first year of life, and most children go on to live completely normal lives.
Types of Clefts
The term “cleft” covers several distinct conditions depending on where the gap forms and how far it extends.
A cleft lip is a split in the upper lip. It can be minor, sometimes called a microform cleft, where the lip looks distorted but isn’t fully separated. An incomplete cleft lip has a visible split through the lip’s border but keeps a small band of tissue connecting the two sides near the nose. A complete cleft lip is a full separation of the lip and the base of the nose on that side.
A cleft palate is an opening in the roof of the mouth. The palate has two parts: the hard palate (the bony front portion) and the soft palate (the flexible tissue toward the back of the throat). A cleft can affect one or both. When the soft palate doesn’t close properly, it can’t rise up to seal off the nasal passages during swallowing and speaking, which causes many of the functional challenges associated with clefts.
A cleft can also be unilateral (on one side) or bilateral (on both sides). Bilateral cleft lips create a more complex situation because the central portion of the upper jaw can shift forward out of alignment, sometimes requiring early intervention to gently reposition it before surgery.
Some babies have a cleft lip only, some have a cleft palate only, and some have both. U.S. data from the CDC shows that cleft lip combined with cleft palate is the most common type, occurring in about 1 in 1,563 births. Isolated cleft palate occurs in roughly 1 in 1,687 births, and cleft lip alone in about 1 in 2,807.
How Clefts Form During Pregnancy
A baby’s face takes shape remarkably early. The lip forms around the sixth week of pregnancy, when tissue from either side of the face grows toward the center and fuses together. If these tissue plates don’t fully meet, a cleft lip results.
The palate develops slightly later, between weeks 6 and 12. It forms from three separate pieces of tissue: one in the middle and two on the sides. These shelves start out vertical, hanging down alongside the tongue, then rotate upward into a horizontal position during weeks 7 and 8. They gradually fuse together from front to back, a process that starts around week 9 and finishes by week 12. Any disruption during this window can leave a gap.
Because the lip and palate form at different times through different processes, a cleft lip and a cleft palate are technically separate events. That’s why a baby can have one without the other.
Causes and Risk Factors
Most clefts result from a combination of genetics and environmental factors. About 70% of cleft lip and palate cases are “nonsyndromic,” meaning the cleft occurs on its own without any other developmental differences. The remaining 30% are linked to broader genetic syndromes that involve additional features beyond the cleft.
On the genetic side, a cleft-related gene can come from either parent. In some cases, a baby inherits a genetic predisposition that only leads to a cleft when combined with certain environmental exposures during pregnancy. Known risk factors include tobacco use, alcohol consumption, and certain medications taken during pregnancy.
Folate (vitamin B9) plays a protective role. The standard recommendation for women of childbearing age is 400 micrograms of folic acid daily, starting before conception and continuing through the first 12 weeks of pregnancy. While this dose was established primarily to prevent neural tube defects like spina bifida, low folate levels during the first trimester are also associated with a higher risk of clefts.
Feeding Difficulties in Newborns
One of the first challenges parents face is feeding. Babies normally create suction to draw milk from a breast or bottle. A cleft palate disrupts this because the opening between the mouth and nasal cavity makes it impossible to build up the negative pressure needed for sucking. The result is long feeding times, less milk consumed per session, and milk coming back up through the nose.
Specialized bottles solve this problem. Products like the Medela SpecialNeeds feeder (formerly called the Haberman feeder), the Dr. Brown’s Specialty Feeding System, and the Pigeon feeder are designed so that a parent can gently squeeze milk into the baby’s mouth, bypassing the need for suction. Cleft teams typically provide these bottles and train parents on how to use them soon after birth.
Hearing and Ear Problems
Children with a cleft palate have a much higher rate of fluid buildup in the middle ear, which can affect hearing. The reason is mechanical. A small muscle in the palate normally opens the Eustachian tube, a tiny channel connecting the middle ear to the back of the throat, each time you swallow. This keeps air pressure balanced and fluid draining. In a cleft palate, that muscle attaches in the wrong position and can’t do its job effectively. Air in the middle ear gets absorbed, negative pressure builds up, and fluid seeps in from the surrounding tissue.
This condition, called middle ear effusion, can muffle hearing during the years when children are learning to speak. Many cleft teams place tiny ventilation tubes (grommets) in the eardrum to keep the middle ear drained. This is sometimes done at the same time as palate repair surgery, sometimes separately if ear problems develop later. Regular hearing checks are a standard part of cleft care throughout childhood.
Surgery and Treatment Timeline
Cleft repair follows a general timeline that begins in infancy. Lip repair surgery is typically performed when a baby is around 3 months old. Palate repair comes later, usually between 6 and 12 months. The goal of early palate surgery is to close the gap before a child starts forming words, giving the soft palate the structure it needs for normal speech development.
These initial surgeries are just the beginning of care for many children. Depending on the severity, additional procedures may be needed as the face grows. Some children require bone grafting in the gum line around age 8 to 10 to support adult teeth. Orthodontic work is common. Older teenagers or young adults sometimes have a final jaw alignment surgery once facial growth is complete.
The Care Team
Cleft care involves more specialists than most parents expect. A dedicated cleft and craniofacial team typically includes surgeons, orthodontists, dentists, audiologists, and speech-language pathologists. Each addresses a different piece of the puzzle: the surgeon closes the structural gap, the orthodontist guides jaw and tooth alignment over years of growth, the audiologist monitors hearing, and the speech-language pathologist works on any speech patterns affected by the palate’s structure.
This team follows a child from birth through late adolescence. Appointments are frequent in the first few years and become less so over time, but the long arc of care means these specialists coordinate closely. Most children’s hospitals with cleft programs schedule multidisciplinary clinic visits where families see several specialists in a single appointment rather than bouncing between offices.