{"id":111608,"date":"2024-09-24T17:06:52","date_gmt":"2024-09-24T08:06:52","guid":{"rendered":"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/"},"modified":"2025-08-22T11:20:37","modified_gmt":"2025-08-22T02:20:37","slug":"accuracy-of-nipt-testing-in-twins","status":"publish","type":"post","link":"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en","title":{"rendered":"NIPT Accuracy in Twin Pregnancies"},"content":{"rendered":"\n<div style=\"border:solid #ffe6e6 0.8rem;background-color: #fff9f9;padding:3% 5%;margin:1rem 0 3rem;\"><div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u76ee\u6b21<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Article_Summary\" >Article Summary<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Accuracy_of_NIPT_in_Twin_Pregnancies\" >Accuracy of NIPT in Twin Pregnancies<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Fetal_DNA_Fraction_in_Maternal_Blood\" >Fetal DNA Fraction in Maternal Blood<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Ratio_of_Fetal_DNA_from_Each_Twin\" >Ratio of Fetal DNA from Each Twin<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Accuracy_by_Medicover_and_Illumina\" >Accuracy by Medicover and Illumina<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Current_Practice_and_Recommendations_for_Twin_NIPT\" >Current Practice and Recommendations for Twin NIPT<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Performing_the_Test\" >Performing the Test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Interpreting_Results\" >Interpreting Results<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Pre-Test_Counseling\" >Pre-Test Counseling<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Unique_Issues_in_Twin_Pregnancies\" >Unique Issues in Twin Pregnancies<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Monochorionic_vs_Dichorionic_Twins\" >Monochorionic vs. Dichorionic Twins<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Detecting_Abnormalities\" >Detecting Abnormalities<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Example_Explanation_to_Patients\" >Example Explanation to Patients<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\/#Summary\" >Summary<\/a><\/li><\/ul><\/nav><\/div>\n<h2 style=\"margin-top:1rem;\"><span class=\"ez-toc-section\" id=\"Article_Summary\"><\/span>Article Summary<span class=\"ez-toc-section-end\"><\/span><\/h2><p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> (Non-Invasive Prenatal Testing) is a method that analyzes cell-free fetal DNA in maternal blood to detect chromosomal abnormalities in the fetus with high accuracy. It is highly effective for assessing the risk of major chromosomal abnormalities, such as Down syndrome (trisomy 21) and Edwards syndrome (trisomy 18). However, many wonder whether the accuracy of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is affected in twin pregnancies.<\/p><\/div>\n\n\n\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Accuracy_of_NIPT_in_Twin_Pregnancies\"><\/span><strong>Accuracy of NIPT in Twin Pregnancies<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> (Non-Invasive Prenatal Testing) is considered accurate even in twin pregnancies, but there are some unique challenges.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Fetal_DNA_Fraction_in_Maternal_Blood\"><\/span><strong>Fetal DNA Fraction in Maternal Blood<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>In twin pregnancies, the total fetal DNA (cffDNA) in the mother\u2019s blood tends to be higher than in single pregnancies. However, this doesn\u2019t necessarily improve accuracy, as the presence of DNA from both fetuses can complicate analysis.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ratio_of_Fetal_DNA_from_Each_Twin\"><\/span><strong>Ratio of Fetal DNA from Each Twin<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>If one fetus has a chromosomal abnormality and the other does not, the mixed DNA might make detection more difficult. This is especially true when the abnormal DNA ratio is low or in dichorionic twins with separate placentas.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Accuracy_by_Medicover_and_Illumina\"><\/span><strong>Accuracy by Medicover and Illumina<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Medicover is reported to maintain high accuracy even in twin pregnancies, and Illumina\u2019s technology is also expected to perform similarly. Though accuracy may slightly decrease in twins, no clear data shows significant decline.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"640\" height=\"427\" src=\"\/nipt\/wp-content\/uploads\/2024\/09\/24200941_s-1.jpg\" alt=\"\u30ca\u30fc\u30b9\" class=\"wp-image-82796\"\/><\/figure>\n\n\n\n    <a href=\"\/nipt\/combined-inspection\/\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u30b3\u30f3\u30d0\u30a4\u30f3\u30c9\u691c\u67fb\u3068\u306f\uff1fNIPT\uff08\u65b0\u578b\u51fa\u751f\u524d\u8a3a\u65ad\uff09\u3068\u306e\u9055\u3044\u3082\u7d39\u4ecb\u3010\u533b\u5e2b\u76e3\u4fee\u3011 <\/div>\n          <div class=\"blog-card-excerpt\">\u51fa\u751f\u524d\u30b9\u30af\u30ea\u30fc\u30cb\u30f3\u30b0\u306e\u57fa\u672c\u3001\u30b3\u30f3\u30d0\u30a4\u30f3\u30c9\u691c\u67fb\u3068NIPT\u306e\u9055\u3044\u3092\u308f\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac\u3057\u307e\u3059\u3002\u3010\u533b\u5e2b\u76e3\u4fee\u3011...<\/div>\n      <\/div>\n    <\/a>\n\n\n\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Current_Practice_and_Recommendations_for_Twin_NIPT\"><\/span><strong>Current Practice and Recommendations for Twin NIPT<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Performing_the_Test\"><\/span><strong>Performing the Test<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is recommended for twin pregnancies, especially when classified as high risk or advised by medical professionals. It offers peace of mind through early screening.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Interpreting_Results\"><\/span><strong>Interpreting Results<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>Extra care is needed when interpreting results in twin pregnancies. A positive result should be followed by diagnostic tests such as amniocentesis or chorionic villus sampling (CVS).<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Pre-Test_Counseling\"><\/span><strong>Pre-Test Counseling<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>It is vital to receive thorough counseling in advance to understand the benefits and limitations of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> in twin pregnancies. This helps patients make informed decisions based on results.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Unique_Issues_in_Twin_Pregnancies\"><\/span><strong>Unique Issues in Twin Pregnancies<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Monochorionic_vs_Dichorionic_Twins\"><\/span><strong>Monochorionic vs. Dichorionic Twins<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Monochorionic Twins<\/strong> share a placenta and have very similar genetic information, making result interpretation relatively straightforward.<br><\/li>\n\n\n\n<li><strong>Dichorionic Twins<\/strong> have separate placentas, which may result in different DNA ratios, making interpretation more complex.<br><\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Detecting_Abnormalities\"><\/span><strong>Detecting Abnormalities<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>If only one fetus has a chromosomal anomaly, test accuracy may be impacted. For a definitive diagnosis, additional testing is necessary.<\/p>\n\n\n\n    <a href=\"\/nipt\/the-wonder-of-twins\/\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u53cc\u5b50\u3092\u6388\u304b\u308b\u4eba\u306e\u7279\u5fb4\u3063\u3066\u3042\u308b\u306e\uff1f\u53cc\u5b50\u306e\u78ba\u7387\u3001\u5224\u660e\u6642\u671f\u3092\u89e3\u8aac\u3010\u533b\u5e2b\u76e3\u4fee\u3011 <\/div>\n          <div class=\"blog-card-excerpt\">\u65e5\u672c\u306b\u304a\u3051\u308b\u591a\u80ce\u598a\u5a20\u306e\u5272\u5408\u306f\u30012017\u5e74\u3067\u306f1.04%\u3067\u3057\u305f\u3002 \u53cc\u5b50\u3092\u6388\u304b\u308b\u4eba\u306b\u7279\u5fb4\u306f\u3042\u308b\u306e\u3067\u3057\u3087\u3046\u304b\uff1f\u53cc\u5b50\u3092\u598a\u5a20\u3059\u308b\u7406\u7531\u3084\u3044\u3064\u308f\u304b\u308b\u306e\u304b\u3001...<\/div>\n      <\/div>\n    <\/a>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Example_Explanation_to_Patients\"><\/span><strong>Example Explanation to Patients<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>When explaining <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> for twins to patients:<\/p>\n\n\n\n<p>\u201cEven in twin pregnancies, <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> can detect chromosomal abnormalities with high accuracy. However, due to the mixture of fetal DNA, results must be interpreted carefully. If the result is positive, further diagnostic testing will be recommended. We will also explain the unique challenges of twin pregnancies and provide detailed counseling, so you can feel reassured.\u201d<\/p>\n\n\n\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Summary\"><\/span><strong>Summary<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> for twin pregnancies offers similar accuracy to singleton pregnancies. However, due to the unique biological factors, interpreting results requires greater care. Patients should be thoroughly informed about the strengths and limitations of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> and receive appropriate counseling. If a positive result is returned, further diagnostic testing will help confirm the finding.<\/p>\n\n\n\n","protected":false},"excerpt":{"rendered":"Article SummaryNIPT &#8230;\n <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/accuracy-of-nipt-testing-in-twins\/?lang=en\">\u7d9a\u304d\u3092\u8aad\u3080<\/a>","protected":false},"author":88,"featured_media":82832,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[97],"tags":[],"class_list":["post-111608","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/111608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/users\/88"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/comments?post=111608"}],"version-history":[{"count":2,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/111608\/revisions"}],"predecessor-version":[{"id":111618,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/111608\/revisions\/111618"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media\/82832"}],"wp:attachment":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media?parent=111608"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/categories?post=111608"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/tags?post=111608"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}