Pregnancy Over 40 and Younger, Down SyndromeWe all know that Down Syndrome is more common in older mothers (but the overall incidence is still rather low).
Neuhäuser and Krackow reviewed and analysed data from 1953 and 1972 (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.