{"id":64923,"date":"2024-03-11T09:10:59","date_gmt":"2024-03-11T08:10:59","guid":{"rendered":"https:\/\/www.juanacrespo.es\/procedimiento-diagnostico-genetico-preimplantacional\/"},"modified":"2024-06-05T17:00:27","modified_gmt":"2024-06-05T16:00:27","slug":"preimplantation-genetic-diagnosis-procedure","status":"publish","type":"post","link":"https:\/\/www.old.juanacrespo.es\/en\/preimplantation-genetic-diagnosis-procedure\/","title":{"rendered":"How is Preimplantation Genetic Diagnosis (PGD) performed?"},"content":{"rendered":"<div class=\"fusion-fullwidth fullwidth-box fusion-builder-row-1 fusion-flex-container nonhundred-percent-fullwidth non-hundred-percent-height-scrolling\" style=\"--awb-border-radius-top-left:0px;--awb-border-radius-top-right:0px;--awb-border-radius-bottom-right:0px;--awb-border-radius-bottom-left:0px;--awb-flex-wrap:wrap;\" ><div class=\"fusion-builder-row fusion-row fusion-flex-align-items-flex-start fusion-flex-content-wrap\" style=\"max-width:1248px;margin-left: calc(-4% \/ 2 );margin-right: calc(-4% \/ 2 );\"><div class=\"fusion-layout-column fusion_builder_column fusion-builder-column-0 fusion_builder_column_1_1 1_1 fusion-flex-column\" style=\"--awb-bg-size:cover;--awb-width-large:100%;--awb-margin-top-large:0px;--awb-spacing-right-large:1.92%;--awb-margin-bottom-large:0px;--awb-spacing-left-large:1.92%;--awb-width-medium:100%;--awb-spacing-right-medium:1.92%;--awb-spacing-left-medium:1.92%;--awb-width-small:100%;--awb-spacing-right-small:1.92%;--awb-spacing-left-small:1.92%;\"><div class=\"fusion-column-wrapper fusion-flex-justify-content-flex-start fusion-content-layout-column\"><div class=\"fusion-text fusion-text-1\"><p><a href=\"https:\/\/www.juanacrespo.es\/en\/treatment\/pgt\/\"><b>Preimplantation Genetic Testing (PGT)<\/b><\/a><span style=\"font-weight: 400;\"> is used to detect possible genetic and\/or chromosomal disorders in embryos obtained during an in vitro fertilization cycle.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In addition to <\/span><b>avoiding the risk of transmitting hereditary genetic diseases<\/b><span style=\"font-weight: 400;\"> from parents to children, this technique allows for the <\/span><b>selection of healthy embryos<\/b><span style=\"font-weight: 400;\">, of higher quality and with more potential for implantation, increasing success in assisted reproduction treatments.<\/span><\/p>\n<h2><strong>What is the procedure for preimplantation genetic diagnosis?<\/strong><\/h2>\n<p><span style=\"font-weight: 400;\">PGD or PGT is a complex process that must always be performed by experts in embryology and genetics, using advanced techniques such as embryonic cell biopsy or molecular genetic analysis.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Its phases are:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>IVF<\/b><span style=\"font-weight: 400;\">. It is the procedure prior to Preimplantation Genetic Diagnosis. After ovarian stimulation of the woman, several mature eggs are obtained (through follicular puncture) and fertilized (with sperm from the male partner or an anonymous donor) using ICSI or intracytoplasmic sperm injection.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Embryonic development<\/b><span style=\"font-weight: 400;\">. Embryos obtained with IVF are observed in their early hours of development to ensure they have the minimum quality necessary for biopsy and to guarantee their survival.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Cell biopsy<\/b><span style=\"font-weight: 400;\">. It consists of extracting one or more cells from the embryo (blastomeres). Biopsy can be performed on day 3 of embryo development or once it has reached the blastocyst stage, 5 days after IVF.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Genetic analysis<\/b><span style=\"font-weight: 400;\">. The sample obtained from the biopsy is placed in a tube. Specialists conduct a study of its chromosomes and genes to identify possible alterations.<\/span><span style=\"font-weight: 400;\"><br \/>\n<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><a href=\"https:\/\/www.juanacrespo.es\/en\/embryo-transfer-aftercare-precautions\/\"><b>Embryo transfer<\/b><\/a><span style=\"font-weight: 400;\">. After obtaining the results of the genetic analysis, genetically healthy embryos are selected for transfer to the mother&#8217;s uterus or cryopreserved for future pregnancy attempts.<\/span><\/li>\n<\/ul>\n<h2><strong>What is the difference between performing the biopsy on day 3 or day 5 of embryonic culture?<\/strong><\/h2>\n<p><span style=\"font-weight: 400;\">Embryonic cell biopsy is possibly the most delicate part of the entire <\/span><b>preimplantation genetic testing (PGT)<\/b><span style=\"font-weight: 400;\"> procedure.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">It must always be <\/span><b>performed by a highly specialized and experienced professional<\/b><span style=\"font-weight: 400;\">, as it is essential not to compromise the embryo&#8217;s viability.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">When the biopsy is performed on the third day of its development, <\/span><b>embryos of good quality have 8 cells<\/b><span style=\"font-weight: 400;\">, and only one of them is extracted by making a hole in the zona pellucida with short laser pulses or chemical agents.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The blastomere is then extracted through this hole by absorption.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If the <\/span><b>biopsy is performed on the fifth day of embryo development<\/b><span style=\"font-weight: 400;\">, it has already become a blastocyst.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The blastocyst is larger, composed of many cells, and has three perfectly differentiated parts (inner cell mass or ICM, blastocoel, and trophectoderm).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">When <\/span><b>performing the biopsy with a blastocyst,<\/b><span style=\"font-weight: 400;\"> short laser pulses are used to create the hole through which several embryonic cells are extracted using a micropipette through aspiration.<\/span><\/p>\n<p><b>Performing the biopsy on the fifth day of embryonic development is simpler<\/b><span style=\"font-weight: 400;\"> because the cells of the ICM and trophectoderm have the same genetic material, and extraction is safer.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">However, at this more advanced stage, it is often necessary to vitrify the embryos after biopsy.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The reason is that the results of the genetic analysis may take several days, and it is not feasible to culture the embryos in the laboratory for such a long time.<\/span><\/p>\n<h2><strong>Preimplantation Genetic Screening<\/strong><\/h2>\n<p><b>Preimplantation genetic screening (PGS)<\/b><span style=\"font-weight: 400;\">, commonly referred to as PGS, is a type of <\/span><b>Preimplantation Genetic Testing (PGT) <\/b><span style=\"font-weight: 400;\">that examines alterations in the number or structure of the embryo&#8217;s chromosomes (aneuploidies). These alterations can result in recurrent miscarriages or the birth of unhealthy children.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The most prevalent test utilized is the <\/span><b>Comparative Genomic Hybridization<\/b><span style=\"font-weight: 400;\"> array, which conducts a Comprehensive Chromosomal Screening assessing the 23 pairs of chromosomes of the embryo.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">To conduct this test, both a control DNA and a DNA sample extracted from the embryonic cell are utilized.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Preimplantation Genetic Diagnosis<\/span><\/h3>\n<p><b>Preimplantation genetic diagnosis (PGD) <\/b><span style=\"font-weight: 400;\">enables the identification of monogenic diseases, which are illnesses caused by mutations in a single gene.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Once the mutation is identified, along with the determination of the type of inheritance (dominant, recessive, or sex-linked), various techniques are employed, with <\/span><b>Polymerase Chain Reaction (PCR)<\/b><span style=\"font-weight: 400;\"> and massive sequencing being the most common for diagnosis.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Advantages of PGD through Massive Sequencing<\/span><\/p>\n<p><b>Massive sequencing <\/b><span style=\"font-weight: 400;\">represents the most advanced method in the preimplantation genetic diagnosis process.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">It permits the examination of the 23 pairs of chromosomes and over 500 genes associated with hereditary diseases in a single test. This includes the <\/span><b>investigation of aneuploidies and monogenic diseases<\/b><span style=\"font-weight: 400;\">, both independently and simultaneously.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Additionally, it offers the <\/span><b>advantage of rapid results acquisition<\/b><span style=\"font-weight: 400;\">, eliminating the need to freeze embryos while awaiting test confirmation.<\/span><\/p>\n<h2><strong>Equipo Juana Crespo: specialists in Advanced Preimplantation Genetic Diagnosis<\/strong><\/h2>\n<h3><strong>When do we recommend undergoing Preimplantation Genetic Testing?<\/strong><\/h3>\n<p><span style=\"font-weight: 400;\">We recommend Preimplantation Genetic Testing in the following cases:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Parents<\/b><span style=\"font-weight: 400;\"> (one or both) <\/span><b>are carriers<\/b><span style=\"font-weight: 400;\">, symptomatic or asymptomatic, of a genetic disease or chromosomal anomaly.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Women who are carriers<\/b><span style=\"font-weight: 400;\"> of an X-linked genetic disease.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Couples who have experienced recurrent miscarriages<\/b><span style=\"font-weight: 400;\"> or implantation failures, in both natural pregnancies and IVF.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Presence of family history<\/b><span style=\"font-weight: 400;\">.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Advanced maternal age<\/b><span style=\"font-weight: 400;\">.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>One of the parents is ill<\/b><span style=\"font-weight: 400;\">.<\/span><\/li>\n<\/ul>\n<h2><strong>When do we perform the biopsy?<\/strong><\/h2>\n<p><span style=\"font-weight: 400;\">At Equipo Juana Crespo, we perform <\/span><b>Preimplantation Genetic Testing<\/b><span style=\"font-weight: 400;\"> on blastocyst-stage embryos, 5-6 days after fertilization.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">At this stage, they have an inner cell mass that will develop into the fetus and an outer layer that will become the placenta (trophectoderm).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The<\/span><b> biopsy<\/b><span style=\"font-weight: 400;\"> is performed on the latter, to avoid affecting fetal development.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Before conducting this test, it is important to have a good number of embryos to discard any anomalies and transfer only those of quality and diagnosed as genetically &#8220;normal.&#8221;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The biopsied samples of all embryos are studied in our own genetics laboratory.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">This, combined with our experience, has allowed us to achieve<\/span> <a href=\"https:\/\/www.juanacrespo.es\/en\/results\/\"><b>one of the highest success rates<\/b><\/a><b> in Preimplantation Genetic Diagnosis<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">What types of preimplantation diagnostic tests do we perform in our clinic?<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Currently, we perform two types of tests for Preimplantation Genetic Testing:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>PGT-A or Preimplantation Genetic Testing for Aneuploidy<\/b><span style=\"font-weight: 400;\">: To determine if the number of chromosomes in an embryo is correct. It is performed in cases of advanced maternal age, couples with altered karyotypes, and patients with recurrent miscarriages or previous interruptions due to chromosomal abnormalities.<\/span><span style=\"font-weight: 400;\">\n<p><\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>PGT-M or Preimplantation Genetic Testing for Monogenic Diseases:<\/b><span style=\"font-weight: 400;\"> To detect monogenic genetic diseases in the embryo before implantation. It is performed on patients with hereditary diseases or with a matching compatibility test for the same disease between the parents. Prior to this, a series of genetic tests must be conducted on the couple and their relatives.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">Do you have questions about the preimplantation genetic diagnosis procedure? Feel free to inquire with us for information, without any obligation.<\/span><\/p>\n<\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":20,"featured_media":63292,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"content-type":"","footnotes":""},"categories":[66,928],"tags":[],"class_list":["post-64923","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-tratamiento-test-genetico-preimplantacional-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/posts\/64923","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/comments?post=64923"}],"version-history":[{"count":2,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/posts\/64923\/revisions"}],"predecessor-version":[{"id":64926,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/posts\/64923\/revisions\/64926"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/media\/63292"}],"wp:attachment":[{"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/media?parent=64923"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/categories?post=64923"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.old.juanacrespo.es\/en\/wp-json\/wp\/v2\/tags?post=64923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}