B5 SCIENCE/HEALTH Challenging a Taboo First cousins can have children together without a great risk of birth defects or genetic disease, scientists say, contradicting widely held beliefs.
According to several recent studies, people living near surface mining sites have a 50percentt greater risk of fatal cancer and a 42percentt greater risk of birth defects than the general population.
For example, babies conceived without treatment by women who had previously had fertility treatments had a 25 percent greater risk for birth defects.
In women, too, aging brings about a decline in the quality of oocytes, leading to a greater chance of birth defects like Down syndrome.
Considering all methods together, there was a 28 percent greater risk for birth defects in babies conceived with fertility treatment, including increased risks for heart, muscle, urogenital and gastrointestinal defects and for cerebral palsy.
A companion study of men who had survived childhood cancer found that their offspring were slightly more likely to be of low birth weight (less than five and a half pounds), but they were not at greater risk for birth defects or prematurity than children born to men who had not had cancer.
Obesity during pregnancy is associated with a greater risk of birth defects, including spina bifida.
In addition, multiple-birth children are at much greater risk of birth defects and/or disabilities and accounted for larger percentage of prenatal deaths [ 29].
In recently conducted research in the UK, it is clear that maternal diabetes during pregnancy is accompanied by a greater risk of birth defects and complicated pregnancy outcomes [ 41].
Current UK guidance is that vulnerable groups of pregnant and breastfeeding women and young children should take vitamin supplements (including vitamins A, C and D) to protect against the greater risk of birth defects and poor health outcomes in later life.
