{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,16]],"date-time":"2026-05-16T09:23:35Z","timestamp":1778923415913,"version":"3.51.4"},"reference-count":15,"publisher":"Wiley","issue":"4","license":[{"start":{"date-parts":[[2003,3,5]],"date-time":"2003-03-05T00:00:00Z","timestamp":1046822400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Prenatal Diagnosis"],"published-print":{"date-parts":[[2003,4]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Objective<\/jats:title><jats:p>To evaluate the diagnostic value of second\u2010trimester maternal serum screening for Down syndrome in twin pregnancies.<\/jats:p><\/jats:sec><jats:sec><jats:title>Method<\/jats:title><jats:p>On the basis of a prospective study of second\u2010trimester maternal serum screening, we studied the distribution of alpha\u2010fetoprotein (AFP) and free \u00df hCG in 3043 twin pregnancies with known outcome. There were 1561 dichorionic and 244 monochorionic pregnancies. The placental type was not available in 1238 cases. We compared 5 screening policies with the same risk, 1\/250, cut\u2010off: maternal age, maternal age corrected for the risk of having at least one affected twin in dichorionic pregnancies, maternal serum marker screening using observed AFP and free \u00df\u2010hCG values divided by a factor of 2, by using the median values actually observed in the global twin population, or by the median values specific to mono\u2010 or dichorionic twins.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>When expressed in singleton\u2010derived MoMs, the median was 2.10 for AFP and 2.11 for free \u00df\u2010hCG. The median AFP did not differ between monochorionic and dichorionic pregnancies. The distribution of free \u00df\u2010hCG was significantly shifted towards greater values in monochorionic (2.16 MoM) compared to dichorionic (2.07) pregnancies (<jats:italic>p<\/jats:italic> &lt; 0.0001). Screened\u2010positive and detection rates were, respectively, 6.6% and 27.3% using maternal age alone, 24.6% and 54.5% using maternal age corrected for the risk of having at least one affected twin in dichorionic pregnancies, 7.75% and 54.5% using observed AFP and free beta\u2010hCG values divided by a factor of 2, 8.05% and 54.5% using the median values actually observed in the global twin population, and 7.75% and 54.5% using the median values specific to mono\u2010 or dichorionic twins.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Trisomy 21 second\u2010trimester maternal serum screening is feasible in twins, and is better than a policy based on maternal age alone. Copyright \u00a9 2003 John Wiley &amp; Sons, Ltd.<\/jats:p><\/jats:sec>","DOI":"10.1002\/pd.594","type":"journal-article","created":{"date-parts":[[2003,4,1]],"date-time":"2003-04-01T19:05:16Z","timestamp":1049223916000},"page":"331-335","source":"Crossref","is-referenced-by-count":48,"title":["Second\u2010trimester Down syndrome maternal serum screening in twin pregnancies: impact of chorionicity"],"prefix":"10.1002","volume":"23","author":[{"given":"Fran\u00e7oise","family":"Muller","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sophie","family":"Dreux","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Henry","family":"Dupoizat","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Serge","family":"Uzan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marie\u2010Fran\u00e7oise","family":"Dubin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean\u2010Fran\u00e7ois","family":"Oury","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bernard","family":"Dingeon","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marc","family":"Dommergues","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2003,3,5]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-4652(199608)168:2<346::AID-JCP13>3.0.CO;2-1"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.1970151209"},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1136\/jms.5.1.3"},{"key":"e_1_2_1_5_1","first-page":"56","volume-title":"Multiple Pregnancy","author":"Fisk NM","year":"1995"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0029-7844(96)00424-3"},{"key":"e_1_2_1_7_1","first-page":"266","article-title":"Nuchal translucency in multiple pregnancies","volume":"41","author":"Monni G","year":"2000","journal-title":"Croat Med J"},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.438"},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0223(199601)16:1<29::AID-PD801>3.0.CO;2-K"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0223(200003)20:3<221::AID-PD787>3.0.CO;2-S"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1996.tb09550.x"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.1970140705"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0223(200002)20:2<91::AID-PD759>3.0.CO;2-X"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.152"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.1991.tb13513.x"},{"key":"e_1_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.1002\/pd.1970140415"}],"container-title":["Prenatal Diagnosis"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fpd.594","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/pd.594","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T13:56:19Z","timestamp":1700229379000},"score":1,"resource":{"primary":{"URL":"https:\/\/obgyn.onlinelibrary.wiley.com\/doi\/10.1002\/pd.594"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2003,3,5]]},"references-count":15,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2003,4]]}},"alternative-id":["10.1002\/pd.594"],"URL":"https:\/\/doi.org\/10.1002\/pd.594","archive":["Portico"],"relation":{},"ISSN":["0197-3851","1097-0223"],"issn-type":[{"value":"0197-3851","type":"print"},{"value":"1097-0223","type":"electronic"}],"subject":[],"published":{"date-parts":[[2003,3,5]]}}}