{"id":39486,"date":"2025-06-23T12:58:21","date_gmt":"2025-06-23T10:58:21","guid":{"rendered":"https:\/\/urecentrogutenberg.es\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/"},"modified":"2025-06-23T12:58:21","modified_gmt":"2025-06-23T10:58:21","slug":"what-is-pre-implantation-genetic-diagnosis-or-pgd","status":"publish","type":"post","link":"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/","title":{"rendered":"What is pre-implantation genetic diagnosis, or PGD?"},"content":{"rendered":"<p><strong>Pre-Implantation Genetic Diagnosis (PGD)<\/strong>\u00a0is a technique used in addition to\u00a0<strong>In Vitro Fertilization (IVF)<\/strong>\u00a0in couples at risk of passing on chromosome or genetic abnormalities to their offspring, among other causes.<\/p>\n<p>It involves carrying out<strong>\u00a0sophisticated genetic testing<\/strong>\u00a0on cells that are\u00a0<strong>biopsied from the embryos obtained<\/strong>\u00a0through IVF to determine whether they\u00a0<strong>carry any chromosome<\/strong>\u00a0or genetic abnormalities.<\/p>\n<p><strong>PGD gives us information<\/strong>\u00a0about each embryo\u2019s status, in turn allowing us to select only healthy embryos to be transferred to the female\u2019s uterus.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Tabla de contenidos<\/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: #3f3f3f;color:#3f3f3f\" 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: #3f3f3f;color:#3f3f3f\" 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 ' ><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/#Current_nomenclature\" >Current nomenclature<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/#What_does_the_pre-implantation_genetic_diagnosis_technique_involve\" >What does the pre-implantation genetic diagnosis technique involve?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/#When_is_use_of_the_pre-implantation_genetic_diagnosis_technique_indicated\" >When is use of the pre-implantation genetic diagnosis technique indicated?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/#Steps_involved_in_pre-implantation_genetic_diagnosis\" >Steps involved in pre-implantation genetic diagnosis<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/#What_is_the_preparation_like_for_a_frozen_embryo_transfer\" >What is the preparation like for a frozen embryo transfer?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/urecentrogutenberg.es\/en\/what-is-pre-implantation-genetic-diagnosis-or-pgd\/#Clinical_outcomes\" >Clinical outcomes<\/a><\/li><\/ul><\/nav><\/div>\n<h3><span class=\"ez-toc-section\" id=\"Current_nomenclature\"><\/span>Current nomenclature<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>PGT-A\u00a0(Pre-Implantation Genetic Testing for Aneuploidies):<\/strong>\u00a0genetic analysis carried out on the embryo to screen for abnormalities in the number of its chromosomes before it is transferred to the uterus.<\/li>\n<li><strong>PGT-SR\u00a0(Pre-Implantation Genetic Testing for Structural Rearrangements):<\/strong>\u00a0genetic analysis carried out on the embryo to screen for abnormalities in the structure of its chromosomes before it is transferred to the uterus.<\/li>\n<li><strong>PGT-M\u00a0(Pre-Implantation Genetic Testing for Monogenic Disorders):<\/strong>\u00a0genetic analysis carried out on the embryo to screen for a disease affecting a single gene before it is transferred to the uterus.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_does_the_pre-implantation_genetic_diagnosis_technique_involve\"><\/span>What does the pre-implantation genetic diagnosis technique involve?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>There are<strong>\u00a0several stages involved<\/strong>\u00a0in the process of PGT-A. Each stage, with the exception of the genetic-molecular testing, is performed at URE Centro Gutenberg. The genetic-molecular testing is carried out at a laboratory that URE Centro Gutenberg works with.<\/p>\n<p>As we mentioned above, we must\u00a0<strong>first carry out a cycle of\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/in-vitro-fertilisation\/\" target=\"_blank\" rel=\"noopener\">In Vitro Fertilization<\/a><\/strong>\u00a0treatment in order to obtain\u00a0embryos.<\/p>\n<p>The<strong>\u00a0embryo biopsy<\/strong>\u00a0is then performed on the\u00a0<strong>embryos<\/strong>, which is the removal of several cells without impacting their development.<\/p>\n<p>Once the biopsy has been taken, the\u00a0<strong>biopsied embryos are\u00a0<\/strong><a href=\"https:\/\/urecentrogutenberg.es\/en\/embryo-freezing-frequently-asked-questions\/\" target=\"_blank\" rel=\"noopener\"><strong>cryopreserved<\/strong><\/a>\u00a0and the cells obtained from the\u00a0<strong>biopsy procedure<\/strong>\u00a0are sent off to a genetic laboratory of reference for processing.<\/p>\n<p>Once we have received the results of the\u00a0<strong>genetic analysis<\/strong>, we can decide which healthy embryo or embryos we are going to transfer depending on chromosomal make-up and characteristics of embryo viability.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"When_is_use_of_the_pre-implantation_genetic_diagnosis_technique_indicated\"><\/span>When is use of the pre-implantation genetic diagnosis technique indicated?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The most common abnormalities are:<\/p>\n<ul>\n<li>\n<ul>\n<li>Genetic abnormalities passed on through the male or female gamete (PGT-SR, PGT-M):\n<ul>\n<li><strong>Diseases<\/strong>\u00a0that only affect one gene, or monogenic illnesses (dominant, recessive or X\u00a0chromosome\u2011linked disorders), whose mutations are known and can be analyzed.<\/li>\n<li><strong>X\u00a0chromosome\u2011linked<\/strong>\u00a0disorders whose gene is unknown or which exhibits certain heterogeneity but can be avoided through gender selection.<\/li>\n<li><strong>Structural abnormalities<\/strong>, such as reciprocal or Robertsonian translocations.<\/li>\n<\/ul>\n<\/li>\n<li>Aneuploidy screening (PGT-A):\n<ul>\n<li><strong><a href=\"https:\/\/urecentrogutenberg.es\/en\/recurrent-pregnancy-loss-what-to-do-when-spontaneous-miscarriage-becomes-a-pattern\/\" target=\"_blank\" rel=\"noopener\">Recurrent Miscarriage<\/a>.<\/strong><\/li>\n<li><strong>Implantation Failure.<\/strong><\/li>\n<li><strong><a href=\"https:\/\/urecentrogutenberg.es\/en\/how-a-females-age-impacts-her-fertility-and-chances-of-becoming-a-mother\/\" target=\"_blank\" rel=\"noopener\">Advanced Maternal Age<\/a>.<\/strong><\/li>\n<\/ul>\n<\/li>\n<li>Other:\n<ul>\n<li><strong>HLA typing<\/strong>\u00a0(histocompatibility).<\/li>\n<li><strong>Chromosome<\/strong>\u00a0abnormalities in sperm.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Steps_involved_in_pre-implantation_genetic_diagnosis\"><\/span>Steps involved in pre-implantation genetic diagnosis<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li><strong>Preliminary steps<\/strong>.\u00a0The preliminary steps include carrying out\u00a0<u>genetic characterization tests for the illnesses to be diagnosed in the parents who are carriers.<\/u> The purpose is to obtain as much information as possible before performing the PGD technique.<\/li>\n<li><strong>Creating the embryos<\/strong>. This next step involves\u00a0<u>obtaining the embryos that will be diagnosed<\/u>. These embryos must be created \u00abin vitro\u00bb using assisted reproduction techniques even if the couple does not have any fertility issues that would make natural conception difficult.<\/li>\n<li><strong>Embryo biopsy:<\/strong>\u00a0this step is carried out on day 5 or 6 following fertilization once the pre\u2011embryo has reached blastocyst stage. It involves\u00a0<u>extracting several cells from the trophectoderm of the pre\u2011embryo<\/u>. Once the biopsy has been completed, the cells obtained are washed to eliminate any potential sources of contamination and are then transferred to small tubes which will be sent by courier to the genetic laboratory of reference, all while maintaining safety, temperature and traceability conditions.<\/li>\n<li><strong>Genetic diagnostic analysis.<\/strong>\u00a0The biopsy that was obtained is processed for analysis before undergoing\u00a0<u>genetic testing at a laboratory of reference.<\/u><\/li>\n<li>Embryo transfer. Depending on the results of the genetic analysis, the medical team and patients make a decision, together, regarding\u00a0<u>which embryos will be transferred based on their genetic\/chromosome make\u2011up and characteristics<\/u>\u00a0of embryo viability.<\/li>\n<li style=\"list-style-type: none;\"><\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"What_is_the_preparation_like_for_a_frozen_embryo_transfer\"><\/span>What is the preparation like for a frozen embryo transfer?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A<strong>\u00a0frozen embryo transfer following<\/strong>\u00a0pre\u2011implantation genetic testing is more straightforward as it does not require the same preparation as with a cycle of\u00a0<strong>in vitro fertilization.<\/strong><\/p>\n<p>This procedure consists in preparing the endometrium to receive the embryo.\u00a0<u>There are two options<\/u>:\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/frozen-embryo-transfer-natural-cycle-versus-hormone-replacement-therapy-hrt\/\" target=\"_blank\" rel=\"noopener\">working with the female\u2019s natural cycle, or by carrying out a cycle of hormone therapy<\/a>\u00a0which includes the administration of estradiol and then progesterone.<\/p>\n<p>Both methods of endometrial preparation have proven to be equally effective in terms of treatment outcomes. For that reason, at\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/\" target=\"_blank\" rel=\"noopener\"><strong>URE Centro Gutenberg<\/strong><\/a>\u00a0the decision to choose one method over the other will depend exclusively on medical criteria, patient comfort and patient well\u2011being.<\/p>\n<p>In the article\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/frozen-embryo-transfer-frequently-asked\/\" target=\"_blank\" rel=\"noopener\">\u2018\u2019Frozen embryo transfer: frequently asked questions about this assisted reproduction treatment,\u2019\u2019<\/a>\u00a0we explain what the preparation for a cryotransfer involves.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Clinical_outcomes\"><\/span>Clinical outcomes<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The\u00a0<strong>overall effectiveness of PGD<\/strong>\u00a0depends on the number of embryos available for testing and their stage of development, performance of the method used to genetically diagnose the cells, and patient age. In addition, when<strong>\u00a0PGD has been indicated due to a monogenic disorder<\/strong>, effectiveness of the diagnostic technique will be influenced by the type of inheritance (recessive versus dominant), which will in turn impact the number of healthy embryos available to the patient at the end of the process. In order to have a reasonable likelihood of success with PGD treatment, the minimum number of embryos needed for testing is 3\u20114 blastocysts. This number is based on our experience and results over recent years. Success rates, however, always depend on each individual case and whether the patients have any previous medical history. Although there have been patients whose treatment resulted in only one embryo that could be biopsied, these types of cases logically have lower success rates.<\/p>\n<p>&nbsp;<\/p>\n<p>Do you still have questions about this assisted reproduction procedure?\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/contact\/\" target=\"_blank\" rel=\"noopener\">Request an appointment with us<\/a>!\u00a0<u>The first consultation is absolutely free<\/u>, and your doctor will thoroughly study your case in order to offer you the best treatment and the highest chances of success.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Pre-Implantation Genetic Diagnosis (PGD)\u00a0is a technique used in addition to\u00a0In Vitro Fertilization (IVF)\u00a0in couples at risk of passing on chromosome or genetic abnormalities to their offspring, among other causes. It involves carrying out\u00a0sophisticated genetic testing\u00a0on cells that are\u00a0biopsied from the embryos obtained\u00a0through IVF to determine whether they\u00a0carry any chromosome\u00a0or genetic abnormalities. PGD gives us information\u00a0about [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":36944,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[499],"tags":[533,571,535,516,505],"class_list":["post-39486","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-assisted-reproduction-treatments-and-techniques","tag-pre-implantation-genetic-diagnosis","tag-preimplantational-genetic-diagnosis-in-gutenberg-centre","tag-reproduction-unit-gutenberg-centre","tag-ure-en","tag-ure-centro-gutenberg-en"],"_links":{"self":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39486","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/comments?post=39486"}],"version-history":[{"count":2,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39486\/revisions"}],"predecessor-version":[{"id":39731,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39486\/revisions\/39731"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/media\/36944"}],"wp:attachment":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/media?parent=39486"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/categories?post=39486"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/tags?post=39486"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}