Cleft palates are one of the most common birth defects worldwide. In the United States, about 1 in 1,563 babies is born with a cleft palate alone, while roughly 1 in 1,031 is born with a cleft lip with or without a cleft palate. Taken together, orofacial clefts affect approximately 1 in 600 to 800 live births globally, adding up to around 220,000 new cases each year.
Cleft Palate vs. Cleft Lip: How the Numbers Break Down
Not all orofacial clefts are the same, and the type matters for both treatment and frequency. When researchers look at the full spectrum of clefts, the typical distribution is:
- Cleft lip and palate combined: about 45% of all cases
- Isolated cleft palate (no lip involvement): about 40%
- Cleft lip alone: about 15%
In the U.S. specifically, NIDCR data from 2010 to 2014 shows about 3,937 babies born each year with cleft lip (with or without cleft palate) and another 2,333 born with cleft palate only. That means roughly 6,270 American families a year navigate a cleft diagnosis of some kind.
Who Is More Likely to Be Affected
Cleft rates vary noticeably by sex. Males are more likely to have a cleft lip, whether or not it extends into the palate. Isolated cleft palate, on the other hand, is more common in females. Researchers treat these as partially distinct conditions with different genetic underpinnings, which helps explain the split.
Ethnicity also plays a role. Populations of Asian and Native American descent tend to have higher rates of orofacial clefts, while populations of African descent tend to have lower rates. White populations fall somewhere in between. These differences hold up across multiple countries and decades of data, suggesting a strong genetic component layered on top of environmental factors.
Family History and Recurrence Risk
Clefts run in families, though most cases occur with no family history at all. When a first-degree relative (parent or sibling) does have a cleft, the risk rises substantially. A large study published in the BMJ found that the relative risk of recurrence in first-degree relatives is about 32 times higher for cleft lip and 56 times higher for isolated cleft palate compared to the general population.
Those multipliers sound alarming, but context helps. Because the baseline risk is small (roughly 1 in 1,500 for isolated cleft palate), even a 56-fold increase translates to a percentage risk that, while meaningful, is far from a certainty. The risk is similar whether the affected relative is a mother, father, or sibling, which suggests the genetic contribution does not depend on which parent carries it.
Syndromic vs. Isolated Cases
About 30% of all cleft lip and palate cases are considered syndromic, meaning the cleft appears alongside other developmental differences as part of a recognized genetic syndrome. Pierre Robin sequence and 22q11.2 deletion syndrome (sometimes called DiGeorge syndrome) are two well-known examples. The remaining 70% are non-syndromic, meaning the cleft is the primary or only structural difference present.
Isolated cleft palate is more likely to be syndromic than cleft lip with or without palate. Up to half of isolated cleft palate cases may be linked to a broader syndrome. This is one reason genetic testing or evaluation is often recommended when a baby is born with a cleft palate alone.
Detecting a Cleft Before Birth
Cleft lip is relatively easy to spot on a routine prenatal ultrasound, with detection rates around 75% in specialized centers. Cleft palate alone is a different story. Because the palate sits inside the mouth and is harder to visualize, prenatal detection rates for isolated cleft palate are extremely low, ranging from 0% to about 11% in most studies, with one Swiss university center reporting just a 2% screening detection rate. Many families learn about a cleft palate only after delivery.
Are Rates Changing Over Time?
Globally, cleft rates have been declining. Between 1990 and 2021, the worldwide incidence rate dropped by roughly 36%. High-middle-income regions saw the steepest reductions, close to 49%, likely reflecting improvements in prenatal nutrition (particularly folic acid supplementation), reduced smoking rates, and better maternal healthcare. High-income regions like North America and Western Europe saw more modest declines of about 22% and 28%, respectively, partly because their rates were already lower to begin with.
Projections through 2050 suggest the incidence rate will continue its gradual decline. Interestingly, though, the overall number of people living with a history of cleft (prevalence) is expected to rise slightly, because survival and access to surgical repair have improved dramatically, especially in lower-income countries. Mortality from orofacial clefts has dropped by 88% since 1990 in regions with advanced healthcare systems, and several high-income areas now report zero cleft-related deaths.
What Drives the Risk
Most orofacial clefts result from a combination of genetic susceptibility and environmental exposures during early pregnancy, when the face and palate are forming (roughly weeks 6 through 12). Known environmental risk factors include smoking during pregnancy, uncontrolled diabetes, obesity, and certain anti-seizure medications taken in the first trimester. Folic acid deficiency has also been linked to higher risk, which is part of why prenatal vitamins are so strongly encouraged.
No single gene causes most clefts. Instead, dozens of genes each contribute a small amount of risk, and their effects combine with environmental triggers. This multifactorial pattern explains why clefts can appear in families with no prior history and why even identical twins don’t always share the condition.