Down syndrome and natural family planning

✍ Scribed by Castilla, Eduardo E.; Simpson, Joe Leigh; Queenan, John T.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 119 KB
• Volume: 66
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/(sici)1096-8628(19961218)66:3<366::aid-ajmg26>3.0.co;2-j

✦ Synopsis

We appreciate the interest of James [1996] in our recent report [Castilla et al., 19951. Of course, it is selfevident that definitively assessing the deleterious effect of aging gametes requires a more rigorous study design, namely, a cohort study in which date of conception is correlated with subsequent outcome. As reported in previous publications Gray et al., 19951, such a study has been underway for several years. Approximately 1,100 pregnancies of couples who used NFP have been ascertained in Chile, Peru, Colombia, Italy, and the United States. Data on congenital anomalies and Down syndrome should be available within a year, further testing the hypothesis with which we and the genetic community have long been intrigued Simpson, 19831. In some of the above citations Simpson et al., 19881, we detail the biologic basis of the aging gamete hypothesis and the pitfalls of extant studies.

Although we acknowledge the inevitable limitations of the case-control design utilized for the study reported in this journal, our work does have several strengths. It is population-based, has a very large sample size, and is characterized by systematic outcome evaluation. Moreover, analyzing women who practice NFP is a step closer to identifying couples a t increased risk for conceptions involving aging gametes than is analysis of a n entire Roman Catholic population or region, given that 4 0 % of Catholics practice NFP. Thus our DoDulation-based data are more useful than several