The question is: How risky is it
really to have a child with your cousin? The answer is: Not nearly as risky as so many other factors for which there is no legislation
The conditions that are of most concern in cousin couples are recessive conditions, where one defective gene is inherited from each parent. First cousins have a 1.5 to 3% increased risk of having a child with birth defects that are inherited. However, some couples may share no recessive traits, and would therefore have no increased risk.
More than four million women become pregnant in America each year, each with a 3% background risk of having a child with a birth defect. Out of those four million women, it is estimated that:
- .1% (4,000) of those women are pregnant by a first cousin
As the charts above indicate, the health risk to unborn children of first cousins is very nominal, particularly when combined with such a low frequency of occurrence.
- 1.1% (45,000) use cocaine
Cocaine use increases the odds of intrauterine growth retardation by 15%, and also significantly increase odds of premature or low birth weight babies and related health problems, stillbirths, and SIDS.
- 2.9% (119,000) smoke marijuana
Marijuana use during pregnancy may reduce the size of the fetus and the birth weight, and related health problems. There is also a 10-fold increase in the risk of nonlymphoblastic leukemia in children whose mothers used marijuana before or during gestation. Marijuana may also increase the risk of chromosomal damage.
- 18.8% (757,000) drink alcohol
Alcohol consumption during pregnancy increases the risk of birth defects by 9%. Additionally,
one out of every 750 newborns are born with FAS(Fetal Alcohol Syndrome.)
- 18-20% of pregnant women are in abusive relationships
Mothers who are in abusive relationships are four times more likely to miscarry, or to have low birth weight or premature babies, and related health problems.
- 20.4% (820,000) smoke cigarettes
Cigarette smoking causes a 1.4 - 2.5% increase of low birth weight and related problems, learning disabilities, and cleft lip and/or palette.
- 25% (1,000,000) are teenagers
Adolescent mothers are 2 to 6 times more likely to have a child with low birth weight or prematurity and its related problems, as well as infant mortality rate and SIDS. Teenagers are also at greater risk for anemia, blood pressure problems, and complicated deliveries.
- Polydrug use during pregnancy
The NIDA National Pregnancy and Health Survey has uncovered a strong link between cigarette smoking and alcohol use and the use of illicit drugs in this population. Among those women who used both cigarettes and alcohol, more than 20 percent also used marijuana and 9.5 percent took cocaine. Conversely, of those women who said they had not used cigarettes or alcohol, only 0.2 percent smoked marijuana and 0.1 percent used cocaine. "This finding reinforces the need for health practitioners to monitor the status of both licit and illicit drug use during pregnancy," said NIDA director Dr. Leshner.
- Pregnancy in women over 35 is on the rise
Mothers who are over 35 are thirty times more likely to have a child with Down's Syndrome. Pregnant women who are 40 or over are one hundred times more likely to give birth to a Down's Syndrome baby. Such chromosomal defects do not follow any hereditary pattern.
Clearly the evidence proves that legislation against first cousin marriages is an unnecessary measure of prevention. There are far more high risk lifestyles to be concerned with. We, as a society, make use of every opportunity to educate women and couples about how their lifestyle choices can affect their unborn children, while allowing them the freedom of choice. Do first cousins deserve any less consideration?
While the risk of birth defects is only very slight, it is still something that all first cousin couples should take into consideration. Genetic Counselors are able to determine the margin of risk for a couple by carefully examining the medical history of both sides of the family. In some cases, if a history of genetic disorder is revealed, blood tests can determine whether the couple actually carry the defective gene.