August 13th, 2008
Scientific evidence suggests that a significant number of occurrences of cleft lip and palate are preventable. If you are planning on having children, and you have a family member with a cleft, our research and educational materials may be able to help you.
Find out more about the prevention of cleft lip and palate. Or, if you are the mother of a child with a cleft, you can learn about steps you can take to reduce the chances of a cleft in your future children.
If you are a parent of a child with cleft lip and palate, you know better than anyone else, how special your son or daughter is.
And as all of us, you want the best for your child. Your child is special–different from others because of cleft. We would like to share with you our present knowledge about the development of clefts, the possible causes, and how to prevent them.
Before you start to read these web pages, please remember not to blame yourself for your child’s cleft. As you will see, finding the cause of cleft development is neither a simple task nor a simple solution.
However there are some general principles, either known for some time or discovered recently, which could substantially reduce the risk for cleft lip and palate.
It may be of interest to you if you are planning to have another child, if you would like to know about the risk for your child’s children, or if you had cleft yourself and are thinking about starting a family.
You have to know what can happen in order to prevent it.
- Orofacial clefts are caused by an interaction between genetic and environmental factors
- It is understood that genetic factors create a “susceptibility” for clefts. When environmental factors (”triggers”) interact with a genetically susceptible genotype, a cleft occurs in the early stages of development.
- Mechanically, a cleft develops when embryonic parts called “processes”, (which are programmed to join with each other and form an individual part of the embryo) do not reach each other in time and an “open space” (cleft) between them persists.
- Processes form embryonic parts by “growing” into an open space by means of cellular multiplication. The processes then touch each other and join together.
- There are several causes that prevent the processes from reaching each other: the rate at which the cells multiply is reduced or inhibited, or the cells which are already present are killed. If these actions occur, then an “open space” (cleft) develops.
How often do clefts occur?
- One baby in every 550 newborns is born with cleft–either only cleft lip, only cleft palate, or cleft lip with cleft palate (CL/P).
- Every day in the U.S., 14 babies with CL/P and 7 babies with CP are born.
Prevalence of Nonsyndromic Orofacial Clefts
and Pierre Robin Sequence
in 2,509,881 California Births (1983-1993)
Prevalence per 1,000 births
Type of cleft Number Rate 95% CI Cleft lip (CL) 718 0.29 0.27, 0.31 Cleft lip and palate (CLP) 1217 0.48 0.46, 0.51 Cleft palate only (CP) 784 0.31 0.29, 0.34
What are the chances of having another baby with a cleft if you have had a child with a cleft or if you were born with a cleft?
When an individual with a cleft overcomes hardship during childhood and adolescence, he or she faces another serious obstacle: the risk that the cleft anomaly could return (recurrence) and affect his or her children. The risk of recurrence varies from 3% to 15%, according to type of cleft and sex of the affected. Also, approximately the same risk of recurrence exists for siblings born after the child with the cleft.
We know the precise figures of recurrence risk, and can provide the family with them during genetic evaluation and counseling. However, the fact that cleft lip and palate, as well as isolated cleft palate, occur in close relatives of affected individuals more often than in the general population, has been known since Danish plastic surgeon Paul Fogh and Andersen published his study more than a century ago.
Similarly, in a large population-based case control study among the California population, Shaw showed that periconceptional multivitamin intake, usually containing 0.4 mg or more of folic acid, reduced the occurrence risk for CL/P by approximately 50%. (”Periconceptional” describes the time period of 2 months before conception and the first trimester of pregnancy.)
- Mothers of 731 children with cleft (cases) and mothers of 734 children without birth defects (controls) were interviewed
- Women who used multivitamins containing 0.4 mg or more folic acid periconceptionally had 27-50% reduction risk for child with orofacial cleft. The highest reduction (by 50%) was found in the subgroup of isolated CL/P.
- Reduced risk in other subgroups:
- CL/P multiple by 39%
- CP isolated by 27%
- CP multiple by 36%