Increased parity and risk of trisomy 21: review of 37 110 live births

摘要

Routine amniocentesis for all women over the age of 35 for detecting trisomy 21 has been the world standard for nearly two decades. It is based on a calculated tradeoff: the documented increased risk of trisomy 21 with advancing age versus the risk of fetal loss secondary to the amniocentesis procedure. Recent data suggest that more specific individual estimates of risk can be made with a combination of maternal age and serum markers. We have reported a trend towards an increased risk of trisomy 21 with increased parity. Given the uniqueness of our population-ultra-Orthodox Jewish mothers who have a high rate of delivery over the age of 35, high parity, and who abstain from prenatal screening and abortion-we had an opportunity to study the interrelation of age and parity.