{"id":105038,"date":"2023-04-20T11:15:02","date_gmt":"2023-04-20T09:15:02","guid":{"rendered":"https:\/\/www.ivi.uk\/?p=105038"},"modified":"2023-02-21T21:16:24","modified_gmt":"2023-02-21T19:16:24","slug":"poor-quality-embryo","status":"publish","type":"post","link":"https:\/\/www.ivi.uk\/blog\/poor-quality-embryo\/","title":{"rendered":"Poor Quality Embryo: Success stories"},"content":{"rendered":"
Anyone going through the undeniably stressful experience of IVF is bound to be familiar with all sorts of jargon associated with embryo development and how embryos are graded. After getting through each stage of the IVF process, from testing and diagnosis to egg collection and fertilisation, it is incredibly disappointing to hear that your embryos are of poor quality. But there is always hope, and plenty of IVF success stories about embryos that have achieved dreams in the face of the extraordinary circumstances.<\/p>\n
Despite technological advances in embryo evaluation, embryo grading remains an art based on embryologists\u2019 years of experience rather than a strictly exact science. Many women and couples have had the thrill of good news after a less-than-promising prognosis. Even for women with a low ovarian reserve, IVF success rates can be excellent, and even poor-quality embryos can end up with a heart-warming success story.\u00a0<\/p>\n
After the fertilisation of eggs in the laboratory, embryologists study embryos as they develop. They are graded and selected for transfer back to the womb at either Day 3 or Day 5 of development, each with different criteria and grading \u2018scores\u2019.<\/p>\n
Day 3 embryos are known as cleavage-stage embryos<\/strong>. The cells have started to divide, or ‘cleave’, but the embryo is not yet growing; it remains the same size as the mature egg that has been fertilised. The number of cells present is one of the criteria by which cleavage-stage embryos are graded. The other is the appearance of the cells and whether there is any fragmentation (where a portion of the cell’s cytoplasm breaks off into a fragment).<\/p>\n Grading is on a scale of 1 to 4, with 1 being good quality and 4 being poor. Typically, a grade 1 cleavage embryo would have at least 6 cells of equal size and no fragmentation. Grade 4 could have cells of equal or unequal size, with moderate to heavy fragmentation.<\/p>\n In the UK, the majority of IVF transfers (75%) are carried out on Day 5<\/a>, at the blastocyst stage, so the way these are graded is likely to be familiar to more people undergoing IVF. In the blastocyst stage, cells have continued to divide, and there are now 100 to 125 cells. They are also growing and differentiating into different types of cells. The two types are the Inner Cell Mass (ICM)<\/a>, which will develop into the foetus, and the Trophectoderm Epithelium (TE), which will become the placenta. Both are essential to a successful pregnancy. Embryos are graded on both on a scale of A to C. Each grade is preceded by a number representing the expansion of the embryo cavity on a scale of 1 (poor) to 6 (good).<\/p>\n The \u2018best\u2019 grade would therefore be 6AA; a poor-quality embryo could be 4CD. However, it\u2019s important to remember that embryos can change their \u2018score\u2019 as they develop and that while the chances of a successful pregnancy from a poor-quality embryo are lower, there is still a real chance.<\/p>\n A 2019 study<\/a>, analysing over 900 euploid embryos, offers us the following data:<\/p>\nBlastocyst stage embryos<\/h3>\n
\n\n
\n Grading<\/strong><\/td>\n Example Grade<\/strong><\/td>\n Live Birth Rate<\/strong><\/td>\n<\/tr>\n \n Excellent<\/td>\n 3AA, 4AA, 5AA, 6AA<\/td>\n 50%<\/td>\n<\/tr>\n \n Good<\/td>\n 3AB, 5AB, 3BA, 5BA, 4AB, 6AB<\/td>\n 49.7%<\/td>\n<\/tr>\n \n Average<\/td>\n 3BB, 4BB, 5BB, 6BB<\/td>\n 42.3%<\/td>\n<\/tr>\n \n Poor<\/td>\n 4BC, 6BC, 5CB, 5BC, 4CB, 6CB<\/td>\n 25%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n