Cleft lip and cleft palate are birth defects that occur when a baby's lip or mouth does not form properly. Together, these birth defects are called "orofacial clefts." Both cleft lip and cleft palate can be corrected. In almost all babies, a series of surgeries can restore normal function while also achieving a normal appearance with minimal scarring.

A baby can have a cleft lip, a cleft palate, or both. Most cases of orofacial clefts are diagnosed after the baby is born, but in rare cases they may be diagnosed during pregnancy (usually during a routine ultrasound). The lip forms between the fourth and seventh weeks of pregnancy; a cleft lip occurs if the tissue that makes up the lip does not join completely before birth. The roof of the mouth or 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 correctly.

Children with a cleft lip alone, children with a cleft palate alone, and children with both cleft lip and palate often have problems with feeding and talking. Nursing is an extremely important issue when a baby is born with orofacial clefts. Le Leche League International advises that "except in rare cases, a baby with a cleft palate cannot get all the milk he needs by breastfeeding alone." A child born with an orofacial cleft might also have ear infections and hearing loss, and they might develop problems with their teeth.

Isolated clefts occuring with no other birth defects are one of the most common birth defects in the U.S.


The Centers for Disease Control and Prevention (CDC) recently estimated that each year, 2,651 babies in the U.S. are born with a cleft palate and 4,437 babies are born with a cleft lip with or without a cleft palate. Cleft lip is more common than cleft palate and, with or without cleft palate, it is generally more common among boys; however, cleft palate occurring alone is more common in girls than boys. About 70 percent of all orofacial clefts are isolated clefts.

Every parent has approximately a one in 600 risk of having a child with an orofacial cleft. Once parents have a child with any type of orofacial cleft, the risk that the next child (and each succeeding child) will be affected runs anywhere from two to five percent. If more than one person in the immediate family has a cleft, that risk rises to approximately one chance in 10.

An individual with an orofacial cleft who is singular in his/her family has a two to five percent chance that his or her child will have a cleft. If the individual with the cleft has a close relative with an orofacial cleft as well, the risk of having a baby born with a cleft increases to, roughly, one in 10. The unaffected siblings of an individual with a cleft have a roughly one percent chance of having a baby with an orofacial cleft, a risk that may rise to five or six percent if more than one close family member has a cleft.

If a genetic syndrome is involved, meaning the cleft is associated with some type of birth disorder, the risk for recurrence within the family could be as high as 50 percent. Clefts have been identified as one feature in over 300 genetic syndromes — a set of physical, developmental, and sometimes behavioral traits that occur together — most of which are quite rare. Syndromes account for roughly 15 percent of the total number of cases of orofacial clefts.

Causes and Risk Factors

Researchers believe that most cases of cleft lip and cleft palate are caused by an interaction of genetic and environmental factors, such as exposures in the environment, maternal diet, and medication use. For many babies, a definite cause is never discovered. To reduce the risk of having a baby born with birth defects, women can take steps before and during pregnancy. Steps include taking a daily multivitamin with folic acid (400 micrograms), not smoking, and not drinking alcohol. The CDC has reported on factors that increase the risk of orofacial clefts:

  • 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 are at an increased risk of having a child with a cleft lip with or without cleft palate.

Two recent studies investigate potential causes and effects of orofacial clefts.


A study conducted by researchers at Mashhad University and Kerman University sought to explore how one environmental factor, maternal stress, impacted the prevalence of orofacial clefts. Specifically, they aimed to investigate how war influenced prevalence. Drawing on records of 101,435 newborn infants delivered in the teaching hospitals of Mashhad and Ahwaz, the researchers analyzed incidence of the anomaly during wartime (1982-1987) and recent years (2005-2010).

Results showed the incidence of orofacial clefts in Mashhad during 1982 to 1987 and 2005 to 2010 were two and 2.2 per 1000 live births, respectively; however, incidence in Ahwaz was one per 1000 during wartime and 0.7 per 1000 live births for recent years.

Thus, the researchers observed no significant differences in prevalence of orofacial clefts during peace and wartime. Because the prevalence in Ahwaz decreased after the war, while prevalence in Mashhad gradually increased, the researchers believe genetic research may be necessary to establish a predisposition in northeast Iran.

Brain Science

In another study conducted at the University of Pittsburgh, researchers chose to explore brain structure in order to determine whether, as has been observed, individuals with nonsyndromic cleft lip (with or without cleft palate) may have a dysmorphic or irregularly shaped corpus callosum.

Midline brain images were obtained from MRI scans of 24 subjects with cleft lip/palate and 40 subjects without this feature. The corpus callosum is made of more than 200 million nerve fibers that connect the left and right sides (hemispheres) of the brain; it functions as a connective pathway. The researchers digitized eight landmarks on the corpus callosum and then applied a geometric morphometrics analysis to test for shape differences across the two groups. Results revealed significant differences in corpus callosum shape; the cleft lip/palate corpus callosum was characterized by increased overall convexity.

The researchers concluded that their results provide additional evidence that midline brain changes may be an important part of the orofacial cleft phenotype.

Sources: Jahanbin A, Kianifar H, Yaghoubi-Al Z, et al. Had prevalence of cleft lip and palate differed during the iran-iraq war? Journal of Craniofacial Surgery. 2013.

Weinberg SM, Parsons TE, Fogel MR, Walter CP, Conrad AL, Nopoulos P. Corpus callosum shape is altered in individuals with nonsyndromic cleft lip and palate. American Journal of Medical Genetics. 2013.