ESSEN, Germany, Oct. 13 (UPI) -- Age is a major factor in whether a woman will give birth to a child with Down syndrome, but it is not the only factor, according to a German study.
The risk of a child being born with Down syndrome is also dependent on how many existing siblings the child has and how big the gap is between the child and his or her immediate preceding sibling, according to Markus Neuhauser and Sven Krackow of the Institute of Medical Informatics, Biometry and Epidemiology at University Hospital Essen in Germany.
The researchers reviewed and analyzed data before abortion was widespread. They found that other factors, besides the mother's increasing age, were linked to the number of Down syndrome cases. Down syndrome rates were significantly higher in older mothers in their first pregnancy than in older mothers who had already had children. Only late first pregnancies were more likely to produce a Down syndrome baby, not late second or third pregnancies.
In addition, the larger the gap between pregnancies, the higher the rates of Down syndrome, according to the study published in Springer's journal Naturwissenschaften.
