{"id":39482,"date":"2025-06-23T12:58:43","date_gmt":"2025-06-23T10:58:43","guid":{"rendered":"https:\/\/urecentrogutenberg.es\/refractory-endometrium-and-assisted-reproduction\/"},"modified":"2025-06-23T12:58:43","modified_gmt":"2025-06-23T10:58:43","slug":"refractory-endometrium","status":"publish","type":"post","link":"https:\/\/urecentrogutenberg.es\/en\/refractory-endometrium\/","title":{"rendered":"Refractory endometrium and assisted reproduction"},"content":{"rendered":"<p>In assisted\u00a0<strong>reproduction treatment<\/strong>\u00a0there are two\u00a0<strong>fundamental objectives<\/strong>\u00a0in order to achieve a pregnancy which will go on to develop correctly.<\/p>\n<p>The first objective is to have at least one\u00a0<strong>embryo for the\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/moments-in-assisted-reproduction-the-embryo-transfer\/\" target=\"_blank\" rel=\"noopener\">embryo transfer<\/a><\/strong>,\u00a0and the second is to help the female achieve a\u00a0<strong>receptive endometrium,<\/strong>\u00a0meaning an endometrium that will be able to successfully accept an embryo and allow it to implant properly. Building off the second objective, today we are going to explain more about what we refer to as a\u00a0<strong>refractory endometrium.<\/strong><\/p>\n<p><a href=\"https:\/\/urecentrogutenberg.es\/en\/recurrent-embryo-implantation-failure-in-assisted-reproduction-treatment-is-there-a-solution\/\" target=\"_blank\" rel=\"noopener\"><strong>Embryo implantation<\/strong><\/a>\u00a0is the process by which an embryo burrows into the surface of the endometrium. For\u00a0<strong>this process to correctly take place<\/strong>, there needs to be a receptive endometrium, a\u00a0<strong>properly functioning embryo in blastocyst stage<\/strong>\u00a0and synchronisation between embryo development and endometrial lining development.<\/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\/refractory-endometrium\/#What_is_the_endometrium\" >What is the endometrium?<\/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\/refractory-endometrium\/#What_is_a_refractory_endometrium\" >What is a refractory endometrium?<\/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\/refractory-endometrium\/#Causes_of_a_refractory_endometrium\" >Causes of a refractory endometrium<\/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\/refractory-endometrium\/#What_solutions_are_available_for_a_refractory_endometrium\" >What solutions are available for a refractory endometrium?<\/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\/refractory-endometrium\/#Is_pregnancy_possible_if_Ive_been_diagnosed_with_a_refractory_endometrium\" >Is pregnancy possible if I\u2019ve been diagnosed with a refractory endometrium?<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What_is_the_endometrium\"><\/span>What is the endometrium?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>The endometrial tissue, or the endometrium<\/strong>, is the inner-most layer which lines the inside of the uterus. Over the course of each\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/what-are-the-main-phases-of-the-menstrual-cycle\/\" target=\"_blank\" rel=\"noopener\">menstrual cycle<\/a>\u00a0the endometrium undergoes significant changes which are crucial to supporting\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/embryo-classification-by-quality-for-in-vitro-fertilisation-treatment\/\" target=\"_blank\" rel=\"noopener\">successful embryo<\/a>\u00a0implantation and, ultimately, conception.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_is_a_refractory_endometrium\"><\/span>What is a refractory endometrium?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>It has been proven that endometrial thickness plays an important role in endometrial receptivity. It is measured and evaluated\u00a0by performing a transvaginal ultrasound before the embryo transfer.<\/p>\n<p>It is well-known that an endometrial\u00a0<strong>lining with the correct appearance<\/strong>\u00a0and thickness is associated with higher implantation and pregnancy success rates, especially when the lining measures more than 7 mm.<\/p>\n<p>An endometrial lining measuring<strong>\u00a0less than 7 mm\u00a0<\/strong>has a direct relationship with\u00a0<strong>lower success rates<\/strong>\u00a0(implantation and pregnancy), in embryo transfer cycles, regardless of whether it was a fresh or\u00a0<strong><a href=\"https:\/\/urecentrogutenberg.es\/en\/frozen-embryo-transfer-frequently-asked\/\" target=\"_blank\" rel=\"noopener\">frozen embryo transfer<\/a>.<\/strong><\/p>\n<p>When the endometrium doesn\u2019t reach a thickness of more than 7\u00a0mm even after using different treatments or therapies to promote its development, it is defined as a \u201crefractory endometrium\u201d.<\/p>\n<p><strong>The incidence of a refractory endometrium is between 0.7 and 2.5%<\/strong>\u00a0of females undergoing assisted reproduction treatment.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Causes_of_a_refractory_endometrium\"><\/span>Causes of a refractory endometrium<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The root cause of a thin endometrium (&lt;7 mm) cannot always be determined, and finding a solution that works is not possible in all cases.<\/p>\n<p><strong>Intrauterine adhesions caused by a prior surgical procedure<\/strong>\u00a0are the most frequent cause of a\u00a0<strong>refractory endometrium.<\/strong><\/p>\n<p>In over 90% of cases, these adhesions are the result of cervical dilation and curettage (D&amp;C) performed following a miscarriage. Other causes include uterine procedures such as<strong>\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/myomas-and-their-implications-on-female-infertility\/\" target=\"_blank\" rel=\"noopener\">fibroid removal<\/a>\u00a0or endometrial ablation.<\/strong><\/p>\n<p>Radiotherapy can also lead to a refractory endometrium, as can endometrial infections such as\u00a0<strong><a href=\"https:\/\/urecentrogutenberg.es\/en\/chronic-endometritis-symptoms-and-treatment\/\" target=\"_blank\" rel=\"noopener\">endometritis<\/a>.<\/strong>\u00a0Congenital uterine abnormalities could also be to blame.<\/p>\n<p>In many cases, a cause cannot be determined and it is considered an idiopathic pathology, meaning spontaneous in origin.<\/p>\n<p>How is a refractory endometrium diagnosed?<\/p>\n<p>2D and 3D vaginal ultrasounds, hysterosonograms and<strong>\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/diagnostic-hysteroscopy-in-assisted-reproduction\/\" target=\"_blank\" rel=\"noopener\">hysteroscopy<\/a><\/strong>\u00a0are the main tools used to diagnose a refractory endometrium.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_solutions_are_available_for_a_refractory_endometrium\"><\/span>What solutions are available for a refractory endometrium?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>In addition to treating the root cause, if one has been pinpointed, there are\u00a0<strong>different alternatives when it comes to trying to improve the patient\u2019s endometrial<\/strong>\u00a0thickness such as prescribing a higher dose of the hormone oestrogen, as well as having the patient take it for a longer amount of time (<a href=\"https:\/\/urecentrogutenberg.es\/en\/ovarian-stimulation-in-assisted-reproduction-we-answer-your-most-frequently-asked-questions\/\" target=\"_blank\" rel=\"noopener\">here<\/a>\u00a0we explain what type of hormones we use in fertility treatment). The administration route of oestrogen can also be changed (i.e. it can be taken orally, vaginally and\/or applied to the skin).<\/p>\n<p>Another option would be to<strong>\u00a0cancel the embryo transfer<\/strong>, freeze the embryos and delay transferring any embryos until a cycle in which the endometrial lining has reached a better thickness (<a href=\"https:\/\/urecentrogutenberg.es\/en\/frozen-embryo-transfer-frequently-asked\/\" target=\"_blank\" rel=\"noopener\">here you can see<\/a>\u00a0how a frozen embryo transfer works).<\/p>\n<p>A frozen embryo transfer can be carried out two different ways: either in a\u00a0<a href=\"https:\/\/urecentrogutenberg.es\/en\/frozen-embryo-transfer-natural-cycle-versus-hormone-replacement-therapy-hrt\/\" target=\"_blank\" rel=\"noopener\">natural cycle, or in a medicated cycle.\u00a0<\/a>In\u00a0<strong>some patients, endometrial thickness is better<\/strong>\u00a0in a natural cycle due to the effects of natural oestrogen production.<\/p>\n<p>Although the points mentioned above are\u00a0<strong>the main treatments used in patients diagnosed with a refractory endometrium<\/strong>, other types of additional treatments for improving endometrial thickness have been noted such as the use of pentoxifylline, aspirin, vitamin E, sildenafil and the intrauterine administration of platelet-rich plasma (PRP).<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Is_pregnancy_possible_if_Ive_been_diagnosed_with_a_refractory_endometrium\"><\/span>Is pregnancy possible if I\u2019ve been diagnosed with a refractory endometrium?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Although it is true that adequate endometrial thickness increases the odds of conceiving, there<strong>\u00a0is no endometrial thickness<\/strong>\u00a0for which achieving a pregnancy is impossible.<\/p>\n<p>In fact,\u00a0<strong>there have been reports of pregnancies that were achieved in patients whose endometrial thickness measured as low as 4 mm.<\/strong><\/p>\n<p>We hope we\u2019ve been able to answer all your questions concerning the refractory endometrium in assisted reproduction. At URE Centro Gutenberg\u00a0we\u2019re here for you, so if you still have questions you simply need to\u00a0<strong><a href=\"https:\/\/urecentrogutenberg.es\/en\/contact\/\" target=\"_blank\" rel=\"noopener\">request an appointment with us and we\u2019ll clarify any additional doubts<\/a>\u00a0<\/strong>at a cost-free initial consultation.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In assisted\u00a0reproduction treatment\u00a0there are two\u00a0fundamental objectives\u00a0in order to achieve a pregnancy which will go on to develop correctly. The first objective is to have at least one\u00a0embryo for the\u00a0embryo transfer,\u00a0and the second is to help the female achieve a\u00a0receptive endometrium,\u00a0meaning an endometrium that will be able to successfully accept an embryo and allow it to [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":37932,"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":[499,497,498,501],"tags":[],"class_list":["post-39482","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-assisted-reproduction-treatments-and-techniques","category-fertility-problems","category-frequently-asked-questions-fertility-and-assisted-reproduction","category-lifestyle-and-fertility-en"],"_links":{"self":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39482","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=39482"}],"version-history":[{"count":3,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39482\/revisions"}],"predecessor-version":[{"id":39727,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/posts\/39482\/revisions\/39727"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/media\/37932"}],"wp:attachment":[{"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/media?parent=39482"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/categories?post=39482"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/urecentrogutenberg.es\/en\/wp-json\/wp\/v2\/tags?post=39482"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}