{"id":77322,"date":"2023-04-06T17:36:51","date_gmt":"2023-04-06T08:36:51","guid":{"rendered":"https:\/\/www.hiro-clinic.or.jp\/nipt\/hidden_vanishing_twin\/"},"modified":"2025-10-16T12:00:46","modified_gmt":"2025-10-16T03:00:46","slug":"hidden_vanishing_twin","status":"publish","type":"post","link":"https:\/\/www.hiro-clinic.or.jp\/nipt\/hidden_vanishing_twin\/?lang=en","title":{"rendered":"&#8220;Hidden Vanishing Twin&#8221; and its relationship with NIPT\u3010Supervised by doctor\u3011"},"content":{"rendered":"\n<style>\nh1, p, p.break-normal{\nword-break: normal;\n}\n#article .post_content p {\nword-break: normal;\n}\n<\/style>\n\n\n\n<div class=\"toc\">\n  <ul>\n    <li><a href=\"#c1\">What is Vanishing Twin?<\/a><\/li>\n    <li><a href=\"#c2\">What is &#8220;Hidden Vanishing Twin&#8221;?<\/a><\/li>\n    <li><a href=\"#c3\">Issues with examination results in the case of &#8220;Hidden Vanishing Twin&#8221;<\/a><\/li>\n    <li><a href=\"#c4\">Types of NIPT (Non-Invasive Prenatal Testing) and &#8220;Hidden Vanishing Twin&#8221;<\/a><\/li>\n  <\/ul>\n  <button class=\"toc_more\">Open Table of Contents<\/button>\n<\/div>\n\n\n\n\n<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\/hidden_vanishing_twin\/?lang=en\/#What_is_Vanishing_Twin\" >What is Vanishing Twin?<\/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\/hidden_vanishing_twin\/?lang=en\/#What_is_%E2%80%9CHidden_Vanishing_Twin%E2%80%9D\" >What is &#8220;Hidden Vanishing Twin&#8221;?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/hidden_vanishing_twin\/?lang=en\/#Issues_with_examination_results_in_the_case_of_%E2%80%9CHidden_Vanishing_Twin%E2%80%9D\" >Issues with examination results in the case of &#8220;Hidden Vanishing Twin&#8221;<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/hidden_vanishing_twin\/?lang=en\/#Types_of_NIPT_Non-Invasive_Prenatal_Testing_and_%E2%80%9CHidden_Vanishing_Twin%E2%80%9D\" >Types of NIPT (Non-Invasive Prenatal Testing) and &#8220;Hidden Vanishing Twin&#8221;<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\" id=\"c1\"><span class=\"ez-toc-section\" id=\"What_is_Vanishing_Twin\"><\/span>What is Vanishing Twin?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>In English, &#8220;Vanishing&#8221; means &#8220;to disappear.&#8221; Therefore, a Vanishing Twin refers to the phenomenon where one of the originally twin fetuses naturally disappears, leaving only one.<\/p>\n\n\n\n<p>In many cases, this occurs due to genetic abnormalities that make survival impossible, resulting in the fetus shrinking or disappearing.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"c2\"><span class=\"ez-toc-section\" id=\"What_is_%E2%80%9CHidden_Vanishing_Twin%E2%80%9D\"><\/span>What is &#8220;Hidden Vanishing Twin&#8221;?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>When initially diagnosed as a twin pregnancy, if during prenatal check-ups only one fetus is confirmed, the diagnosis of Vanishing Twin occurs.<\/p>\n\n\n\n<p>However, in some cases, despite being a twin pregnancy, it may be diagnosed as a singleton. This could happen because one fetus is too small to detect or its heartbeat has ceased, making it difficult to find at an early stage before heartbeat activity can be observed, and therefore cannot be confirmed through ultrasound (sonogram) examination.<\/p>\n\n\n\n<p>Among cases where only one fetus was initially considered during pregnancy, those where one of the twin fetuses has disappeared are defined as &#8220;Hidden Vanishing Twin.&#8221;<\/p>\n\n\n\n    <a href=\"\/nipt\/vanishing-twins\/\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u30d0\u30cb\u30b7\u30f3\u30b0\u30c4\u30a4\u30f3\u3063\u3066\u306a\u306b\uff1f\u53cc\u5b50\u306e\u598a\u5a20\u3067\u77e5\u3063\u3066\u304a\u304d\u305f\u3044\u3053\u3068\u3010\u533b\u5e2b\u76e3\u4fee\u3011 <\/div>\n          <div class=\"blog-card-excerpt\">\u53cc\u5b50\u306e\u7247\u65b9\u304c\u6d88\u3048\u305f\u3088\u3046\u306b\u898b\u3048\u308b\u300c\u30d0\u30cb\u30b7\u30f3\u30b0\u30c4\u30a4\u30f3\u300d\u3002\u53cc\u5b50\u306e\u598a\u5a20\u3067\u306f\u73cd\u3057\u304f\u306a\u3044\u73fe\u8c61\u3067\u3059\u304c\u3001\u7a81\u7136\u544a\u3052\u3089\u308c\u308b\u3068\u30b7\u30e7\u30c3\u30af\u3092\u53d7\u3051\u308b\u3053\u3068\u3067\u3057\u3087\u3046\u3002\u30d0\u30cb\u30b7...<\/div>\n      <\/div>\n    <\/a>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"c3\"><span class=\"ez-toc-section\" id=\"Issues_with_examination_results_in_the_case_of_%E2%80%9CHidden_Vanishing_Twin%E2%80%9D\"><\/span>Issues with examination results in the case of &#8220;Hidden Vanishing Twin&#8221;<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>In genetic testing, in cases of &#8220;Hidden Vanishing Twin&#8221; where one fetus has disappeared or diminished but is recognized as a singleton, it&#8217;s common to inadvertently pick up the genes of the vanished or diminished fetus. Even if the fetus is small in size, highly accurate <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> (Non-Invasive Prenatal Testing) can detect these genes in the mother&#8217;s blood.<\/p>\n\n\n\n<p>Generally, the causes of Vanishing Twin are known to be related to chromosomal abnormalities such as <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/edwards-syndrome\/?lang=en\">Trisomy 18<\/a> or <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/patau-syndrome\/?lang=en\">Trisomy 13<\/a>.<\/p>\n\n\n\n<p>If a fetus with trisomy disappears and <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> (Non-Invasive Prenatal Testing) is conducted, it will be detected as positive. However, if amniocentesis is performed for the surviving fetus for definitive diagnosis, the result will be negative. In this case, the <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> result would be a false positive.<\/p>\n\n\n\n<p>However, in the case of &#8220;Hidden Vanishing Twin,&#8221; a positive result in genetic testing is indeed a valid result.<\/p>\n\n\n\n    <a href=\"\/nipt\/faq\/#381-2\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u3088\u304f\u3042\u308b\u8cea\u554f <\/div>\n          <div class=\"blog-card-excerpt\">\u7686\u69d8\u304b\u3089\u3088\u304f\u3044\u305f\u3060\u304f\u8cea\u554f\u3092\u307e\u3068\u3081\u307e\u3057\u305f\u3002NIPT\u306b\u3064\u3044\u3066\u5b89\u5fc3\u3057\u3066\u691c\u67fb\u3092\u53d7\u3051\u3089\u308c\u308b\u3088\u3046\u3001\u7686\u69d8\u306e\u7591\u554f\u306b\u304a\u7b54\u3048\u3044\u305f\u3057\u307e\u3059\u3002...<\/div>\n      <\/div>\n    <\/a>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"c4\"><span class=\"ez-toc-section\" id=\"Types_of_NIPT_Non-Invasive_Prenatal_Testing_and_%E2%80%9CHidden_Vanishing_Twin%E2%80%9D\"><\/span>Types of NIPT (Non-Invasive Prenatal Testing) and &#8220;Hidden Vanishing Twin&#8221;<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Generally, <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/nipt\/\">NIPT (Non-Invasive Prenatal Testing)<\/a> is thought to have only one method, but there are currently several types depending on the type of device used.<\/p>\n\n\n\n<p>The Veriseq V2 system, which is a widely used type of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> (Non-Invasive Prenatal Testing) device based on Whole Genome sequencing, cannot distinguish between the genes of the two fetuses in the case of a &#8220;Hidden Vanishing Twin.&#8221; Therefore, it is not possible to determine which fetus has abnormalities. While this may not be a significant issue when the pregnancy is known to be a twin pregnancy from the beginning, in the case of &#8220;Hidden Vanishing Twin,&#8221; the <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> results may be falsely positive.<\/p>\n\n\n\n<p>On the other hand, the Cyprus method, a Target type of <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a>, can differentiate between the genes of the two fetuses. This allows for diagnosing one fetus with trisomy while the other is normal.<\/p>\n\n\n\n<p>If <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> is being considered for someone already diagnosed with Vanishing Twin, it&#8217;s recommended to opt for the Cyprus method. However, it&#8217;s important to note that the Cyprus method can only detect a limited number of chromosomes (13, 18, 21) due to its nature of deeply analyzing each one.<\/p>\n\n\n\n<p>In contrast, the Veriseq V2 system, which uses the Whole Genome type of testing, can examine all chromosomes. This means it can detect the total number of chromosomes as well as partial deletions or duplications of autosomes.<\/p>\n\n\n\n<p>Thus, by employing multiple testing methods, <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a> can now conduct a wide range of examinations. For those considering <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/\">NIPT<\/a>, choosing the appropriate testing method based on the situation is advisable.<\/p>\n\n\n\n    <a href=\"\/nipt\/plan\/n-scan\/\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u975e\u516c\u958b: N-Scan\u30d7\u30e9\u30f3\u4e00\u89a7 <\/div>\n          <div class=\"blog-card-excerpt\">\u30d2\u30ed\u30af\u30ea\u30cb\u30c3\u30afNIPT\u306eN-\u30b9\u30ad\u30e3\u30f3\u30d7\u30e9\u30f3\u3002\u6700\u5148\u7aef\u306e\u975e\u4fb5\u8972\u6027\u80ce\u5150\u67d3\u8272\u4f53\u7570\u5e38\u691c\u67fb\u3067\u3001\u598a\u5a20\u521d\u671f\u306e\u4e0d\u5b89\u3092\u89e3\u6d88\u3057\u3001\u5b89\u5fc3\u306e\u30de\u30bf\u30cb\u30c6\u30a3\u30e9\u30a4\u30d5\u3092\u30b5\u30dd\u30fc\u30c8\u3057...<\/div>\n      <\/div>\n    <\/a>\n\n\n\n    <a href=\"\/nipt\/plan\/n-guard\/\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u975e\u516c\u958b: N-Guard\u30d7\u30e9\u30f3\u4e00\u89a7 <\/div>\n          <div class=\"blog-card-excerpt\">\u30d2\u30ed\u30af\u30ea\u30cb\u30c3\u30afNIPT\u306eN-\u30ac\u30fc\u30c9\u30d7\u30e9\u30f3\u3002\u5148\u9032\u306e\u975e\u4fb5\u8972\u6027\u691c\u67fb\u3067\u598a\u5a20\u4e2d\u306e\u4e0d\u5b89\u3092\u8efd\u6e1b\u3057\u3001\u6bcd\u5b50\u306e\u5065\u5eb7\u3092\u5b88\u308b\u305f\u3081\u306e\u6700\u826f\u306e\u9078\u629e\u3092\u3054\u63d0\u6848\u3002...<\/div>\n      <\/div>\n    <\/a>\n\n\n\n    <a href=\"\/nipt\/plan\/n-advance\/\" class=\"blog-card\">\n      <div class=\"blog-card-content\">\n          <div class=\"blog-card-title\">\u975e\u516c\u958b: N-Advance\u30d7\u30e9\u30f3\u4e00\u89a7 <\/div>\n          <div class=\"blog-card-excerpt\">\u30d2\u30ed\u30af\u30ea\u30cb\u30c3\u30afNIPT\u306eN-Advance\u30d7\u30e9\u30f3\u306f\u3001\u7dcf\u5408\u7684\u306a\u30b1\u30a2\u3068\u30b5\u30dd\u30fc\u30c8\u3067\u598a\u5a20\u671f\u9593\u4e2d\u306e\u4e0d\u5b89\u3092\u8efd\u6e1b\u3002\u4fe1\u983c\u3067\u304d\u308b\u691c\u67fb\u30b5\u30fc\u30d3\u30b9\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002...<\/div>\n      <\/div>\n    <\/a>\n","protected":false},"excerpt":{"rendered":"What is Vanishing Tw&#8230;\n <a href=\"https:\/\/www.hiro-clinic.or.jp\/nipt\/hidden_vanishing_twin\/?lang=en\">\u7d9a\u304d\u3092\u8aad\u3080<\/a>","protected":false},"author":13,"featured_media":64538,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[203],"tags":[],"class_list":["post-77322","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-genetic-sequence"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/77322","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\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/comments?post=77322"}],"version-history":[{"count":4,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/77322\/revisions"}],"predecessor-version":[{"id":118329,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/posts\/77322\/revisions\/118329"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media\/64538"}],"wp:attachment":[{"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/media?parent=77322"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/categories?post=77322"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hiro-clinic.or.jp\/nipt\/wp-json\/wp\/v2\/tags?post=77322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}