{"id":39458,"date":"2025-06-23T12:58:48","date_gmt":"2025-06-23T10:58:48","guid":{"rendered":"https:\/\/urecentrogutenberg.es\/embryo-freezing-frequently-asked-questions-about-this-assisted-reproduction-technique\/"},"modified":"2025-09-29T13:09:24","modified_gmt":"2025-09-29T11:09:24","slug":"embryo-freezing-frequently-asked-questions","status":"publish","type":"post","link":"https:\/\/urecentrogutenberg.es\/en\/embryo-freezing-frequently-asked-questions\/","title":{"rendered":"Embryo freezing: frequently asked questions about this assisted reproduction technique"},"content":{"rendered":"<p>The <strong>embryo freezing<\/strong> by <strong>vitrification<\/strong>, or ultra\u2011rapid freezing, is one of the assisted <strong>reproduction techniques<\/strong> we perform at URE Centro Gutenberg. It\u2019s a very useful procedure as it allows us to<strong>\u00a0preserve the embryos that aren\u2019t going to be transferred<\/strong>\u00a0in the same cycle. This may be because there are additional embryos remaining after the embryo transfer is carried out, or because the woman\u2019s endometrium isn\u2019t prepared for an embryo transfer. In both cases, the embryos are vitrified so that they may be transferred in a later cycle.<\/p>\n<p>Our experience tells us\u00a0<strong>how often we are able to freeze remaining embryo<\/strong><strong>s<\/strong>. This is possible around\u00a020%\u00a0to\u00a030% of the time when carrying out IVF treatment with own eggs, and around\u00a040%\u00a0to\u00a050% of the time when carrying out treatment with donated oocytes, or egg donation.<\/p>\n<p>You most likely have doubts about this assisted reproduction technique. We are aware that it\u00a0<strong>usually leads to many questions<\/strong>, and these have become a recurring topic in our fertility consultations. That is why today we would like to answer several of these frequently asked questions for you.<\/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 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/urecentrogutenberg.es\/en\/embryo-freezing-frequently-asked-questions\/#How_are_the_embryos_frozen\" >How are the embryos frozen?<\/a><\/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\/embryo-freezing-frequently-asked-questions\/#Do_the_embryos_offer_the_same_chances_of_success_once_they_are_thawed\" >Do the embryos offer the same chances of success once they are thawed?<\/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\/embryo-freezing-frequently-asked-questions\/#How_long_can_embryos_remain_frozen\" >How long can embryos remain frozen?<\/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\/embryo-freezing-frequently-asked-questions\/#How_is_a_cryotransfer_or_a_frozen_embryo_transfer_treatment_carried_out\" >How is a cryotransfer, or a frozen embryo transfer treatment, carried out?<\/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\/embryo-freezing-frequently-asked-questions\/#What_quality_do_frozen_embryos_usually_have\" >What quality do frozen embryos usually have?<\/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\/embryo-freezing-frequently-asked-questions\/#What_is_the_survival_rate_of_frozen_embryos\" >What is the survival rate of frozen embryos?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/urecentrogutenberg.es\/en\/embryo-freezing-frequently-asked-questions\/#What_happens_if_I_no_longer_need_the_frozen_embryos\" >What happens if I no longer need the frozen embryos?<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"How_are_the_embryos_frozen\"><\/span>How are the embryos frozen?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Vitrification is an ultra\u2011rapid freezing system in which<strong>\u00a0we introduce the embryos into liquid nitrogen<\/strong>. With this technique, the temperature of the embryos instantly drops from 23 degrees to negative 196 degrees.<\/p>\n<p>This extremely elevated cooling speed, along with the use of cryo\u2011protectors, prevents the formation of ice crystals, in turn\u00a0<strong>preventing damage to cell structures<\/strong>. This way, upon thawing, the embryos will resume cell division and development without disruption.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Do_the_embryos_offer_the_same_chances_of_success_once_they_are_thawed\"><\/span>Do the embryos offer the same chances of success once they are thawed?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Nowadays, using frozen embryos from\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/in-vitro-fertilisation-questions-assisted-reproduction-treatment\/\" target=\"_blank\" rel=\"noopener noreferrer\">a cycle of In Vitro Fertilisation<\/a>\u00a0gives us practically the\u00a0<strong>same likelihood of pregnancy<\/strong>\u00a0as when fresh embryos are used.<\/p>\n<p>In fact, an increasing number of studies are demonstrating similar success rates between fresh and frozen embryos. There are even authors who indicate higher pregnancy success rates when using frozen embryos.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_long_can_embryos_remain_frozen\"><\/span>How long can embryos remain frozen?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Once they\u2019ve been vitrified, embryos can remain in storage in this state\u00a0<strong>for an unlimited amount of time<\/strong>.<\/p>\n<p>Additionally, the amount of time the embryos remain frozen\u00a0<strong>will not impact their quality<\/strong>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_is_a_cryotransfer_or_a_frozen_embryo_transfer_treatment_carried_out\"><\/span>How is a cryotransfer, or a frozen embryo transfer treatment, carried out?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A frozen embryo transfer is more straightforward and less expensive as it\u00a0<strong>does not involve the same preparation as a cycle of in vitro fertilisation<\/strong>\u00a0which requires daily injections, sedation, the operating theatre, etc.<\/p>\n<p>This treatment consists in preparing the endometrium to receive the embryos. There are two options:\u00a0<strong>in a natural cycle, or in a stimulated cycle<\/strong>\u00a0involving the repeated administration of the hormones estradiol and progesterone.<\/p>\n<p>Both methods of endometrial preparation have shown to be\u00a0<strong>equally effective in terms of results<\/strong>. For this reason, at URE Centro Gutenberg choosing one method or another will be exclusively based on medical criteria and on the comfort and safety of the patient.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_quality_do_frozen_embryos_usually_have\"><\/span>What quality do frozen embryos usually have?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Embryo quality at the time of thawing is the\u00a0<strong>same as when they were initially frozen<\/strong>. This means that the embryos will present the same morphological characteristics.<\/p>\n<p><strong>In rare cases embryo quality may be altered<\/strong>\u00a0upon thawing or the embryos may not survive the thawing process.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_is_the_survival_rate_of_frozen_embryos\"><\/span>What is the survival rate of frozen embryos?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The success rate of this technique\u00a0<strong>will depend on embryo quality\u00a0<\/strong>and on the embryo\u2019s ability to survive the freezing process. Here we can clearly see the difference between embryos from a cycle of\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/in-vitro-fertilisation\/\" target=\"_blank\" rel=\"noopener noreferrer\">in vitro fertilisation<\/a>\u00a0with own eggs compared to\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/egg-donation\/\" target=\"_blank\" rel=\"noopener noreferrer\">donated oocytes, or egg donation<\/a>.<\/p>\n<p>The survival rate is around 97% when the embryos have come from a cycle of\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/egg-donation-common-questions\/\" target=\"_blank\" rel=\"noopener noreferrer\">egg donation<\/a>, and around 90% when they\u2019ve come from a cycle of IVF with own eggs. The<strong>\u00a0likelihood of achieving a viable pregnancy, on average, is around 51%<\/strong>.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_happens_if_I_no_longer_need_the_frozen_embryos\"><\/span>What happens if I no longer need the frozen embryos?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>According to\u00a0<strong>Spanish Law on Assisted Reproduction (Law 14\/2006)<\/strong>, the possible uses that can be given to the cryopreserved embryos remaining following a cycle of IVF are clear: they can be used in the future by the same woman\/couple, they can be donated for reproductive or scientific purposes, or they must be destroyed.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The embryo freezing by vitrification, or ultra\u2011rapid freezing, is one of the assisted reproduction techniques we perform at URE Centro Gutenberg. It\u2019s a very useful procedure as it allows us to\u00a0preserve the embryos that aren\u2019t going to be transferred\u00a0in the same cycle. This may be because there are additional embryos remaining after the embryo transfer [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[499,498],"tags":[538,528,512,504,529,545,521,522,532,546,534,547,519,518,508,540,513,503,541,514,510,506,535,515,516,505,530],"class_list":["post-39458","post","type-post","status-publish","format-standard","hentry","category-assisted-reproduction-treatments-and-techniques","category-frequently-asked-questions-fertility-and-assisted-reproduction","tag-artificial-insemination","tag-assisted-reproduction","tag-assisted-reproduction-clinic-in-malaga","tag-assisted-reproduction-techniques","tag-causes-of-infertility","tag-donate-eggs-in-malaga","tag-egg-donation-in-algeciras","tag-egg-donation-in-malaga","tag-embryo-cryopreservation","tag-embryo-freezing","tag-embryo-transfer","tag-embryo-vitrification","tag-female-fertility","tag-fertility-clinic","tag-fertility-clinic-in-malaga","tag-fertility-preservation","tag-fertility-treatments-in-malaga","tag-in-vitro-fertilisation","tag-infertility","tag-ivf","tag-ivf-clinic-in-malaga","tag-pregnancy","tag-reproduction-unit-gutenberg-centre","tag-reproductive-treatments","tag-ure-en","tag-ure-centro-gutenberg-en","tag-vitrification"],"_links":{"self":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39458","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=39458"}],"version-history":[{"count":5,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39458\/revisions"}],"predecessor-version":[{"id":40190,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39458\/revisions\/40190"}],"wp:attachment":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/media?parent=39458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/categories?post=39458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/tags?post=39458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}