{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,6]],"date-time":"2026-06-06T07:31:03Z","timestamp":1780731063404,"version":"3.54.1"},"reference-count":10,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2005,6,3]],"date-time":"2005-06-03T00:00:00Z","timestamp":1117756800000},"content-version":"vor","delay-in-days":5601,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Am. J. Med. Genet."],"published-print":{"date-parts":[[1990,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Maternal age\u2010specific rates of chromosome abnormalities in women undergoing chorionic villus sampling (CVS) were evaluated. These were rates derived from regression equations of the form rate = 1n(<jats:italic>b<\/jats:italic> [age] + <jats:italic>c<\/jats:italic>) where age varied from 35 to 48 years; and <jats:italic>b<\/jats:italic> and <jats:italic>c<\/jats:italic> are parameters. For Down syndrome (47, + 21), <jats:italic>b<\/jats:italic> = 0.29 and <jats:italic>c<\/jats:italic> = \u221215.53; for other nonmosaic abnormalities, <jats:italic>b<\/jats:italic> = 0.25 and c = \u221214.11; and, for all abnormalities, <jats:italic>b<\/jats:italic> = 0.27 and <jats:italic>c<\/jats:italic> = \u221214.22. The predicted rates per 1,000 varied, respectively, from 4.2, 4.6, and 8.8 at age 35 years to 180.0, 120.0, and 300.0 at age 48 years. The predicted numbers of abnormalities were compared with those observed in an overlapping data set reported in the literature. For 47, + 21, the ratio of observed (O) to expected (E) numbers was 54\/56.4 = 0.96, suggesting that these rates are at least not grossly erroneous. For non\u201047, + 21 chromosome abnormalities, the ratio of O to E was 66\/51.1 = 1.29. The possibility of geographic variation in rates of non\u201047, + 21 chromosome abnormalities cannot be dismissed. Finally, if 1) the regression derived rates are correct, 2) there is no difference in <jats:italic>selective<\/jats:italic> loss of chromosome abnormalities between younger and older mothers, and 3) the ratio of rates at ages 35 and 40 years to those in the women of all ages are the same for all abnormalities at CVS as for 47, + 21 in live births, then the proportion of all women with viable conceptuses at time of CVS who have an embryo or fetus with cytogenetic abnormality is 3.8\u20134.4 per 1,000 conceptuses.<\/jats:p>","DOI":"10.1002\/ajmg.1320350209","type":"journal-article","created":{"date-parts":[[2005,6,12]],"date-time":"2005-06-12T03:39:08Z","timestamp":1118547548000},"page":"184-187","source":"Crossref","is-referenced-by-count":18,"title":["Chromosome abnormalities in older women by maternal age: Evaluation of regression\u2010derived rates in chorionic villus biopsy specimens"],"prefix":"10.1002","volume":"35","author":[{"given":"Ernest B.","family":"Hook","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2005,6,3]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.1970040704"},{"key":"e_1_2_1_3_1","series-title":"BD:OAS","first-page":"249","volume-title":"Sex Differentiation and Chromosomal Abnormalities","author":"Hook EB","year":"1978"},{"key":"e_1_2_1_4_1","first-page":"282","article-title":"Rates of chromosomal abnormality at different maternal ages","volume":"58","author":"Hook EB","year":"1981","journal-title":"Obstet and Gynecol"},{"key":"e_1_2_1_5_1","first-page":"96","article-title":"Chromosome abnormalities and spontaneous fetal deaths following amniocentesis: Further data and associations with maternal age","volume":"35","author":"Hook EB","year":"1983","journal-title":"Am J Hum Genet"},{"key":"e_1_2_1_6_1","first-page":"474","article-title":"Maternal age\u2010specific rates of chromosome abnormalities at chorionic villus study: a revision","volume":"45","author":"Hook EB","year":"1989","journal-title":"Am J Hum Genet"},{"key":"e_1_2_1_7_1","unstructured":"HookEB CrossPK JacksonL PergamentE BrambatiB(1988): Maternal age specific rates of 47 + 21 and other cytogenetic abnormalities diagnosed in the first trimester of pregnancy and using chorionic villus biopsy specimens: Comparison with rates expected for amniocentesis.Am J Hum Genet(in press)."},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF00418391"},{"key":"e_1_2_1_9_1","first-page":"597","volume-title":"Human Genetics (Proceedings of the 7th International Congress of Human Genetics, West Berlin, 1986)","author":"Mikkelsen M","year":"1987"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF00276595"},{"key":"e_1_2_1_11_1","unstructured":"WarburtonD ByrneJ(1986):Estimates of the prevalence of chromosome anomalies expected in chorionic villus sampling procedures."}],"container-title":["American Journal of Medical Genetics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fajmg.1320350209","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ajmg.1320350209","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T00:28:53Z","timestamp":1698020933000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/ajmg.1320350209"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,2]]},"references-count":10,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1990,2]]}},"alternative-id":["10.1002\/ajmg.1320350209"],"URL":"https:\/\/doi.org\/10.1002\/ajmg.1320350209","archive":["Portico"],"relation":{},"ISSN":["0148-7299","1096-8628"],"issn-type":[{"value":"0148-7299","type":"print"},{"value":"1096-8628","type":"electronic"}],"subject":[],"published":{"date-parts":[[1990,2]]}}}