This post explains how embryos can split during IVF, especially at the blastocyst stage. It covers the timing of splitting, the different types of identical twins, the factors that make splitting more likely, and how IVF labs can reduce the risk of twins after single embryo transfer.
This post traces the evolution of PGT-A testing in IVF, from early FISH and microarray methods to modern NGS and emerging technologies like nanopore sequencing, highlighting how each advancement improved accuracy, speed, and embryo assessment.
Aneuploid embryos, with an abnormal number of chromosomes, are a major cause of miscarriages, often linked to maternal age and errors in meiosis. In this post, we’ll explore what chromosomes and aneuploidy are, how meiosis errors cause aneuploidy, and the factors contributing to these errors, including age, genetics and mitochondrial dysfunction.
The egg cell contains a high number of mitochondria, which are tiny cellular organs that produce energy that the egg needs to power fertilization and embryo development. Research has shown that these mitochondria can become dysfunctional with age, leading to reduced energy availability for the egg that could result in poor egg quality. Different treatments that target mitochondria, like antioxidant supplements or mitochondrial donation, may improve egg quality, although good quality research is lacking that shows these treatments are truly effective.
Laparoscopy is the gold standard for diagnosing endometriosis, but other non-surgical tests are showing potential. Here we’ll take a brief look at ReciptivaDx based on the BCL6 protein, the Endotest and DotEndo test based on a miRNA signature, the EMScore which is based on a gene expression signature, and imaging tests like ultrasound and MRI.
This post reviews what research currently shows about the vaginal and endometrial microbiome and how it may relate to fertility and IVF outcomes. While Lactobacillus species are often considered beneficial and are commonly found in the reproductive tract, studies examining whether microbiome differences actually affect IVF success have produced mixed results.
Evidence up to 2022 shows that a single PGT-A biopsy is highly concordant (similar) with the rest of the embryo when the embryo is aneuploid or euploid, but not when it’s mosaic or segmental.
The post discusses various frozen embryo transfer protocols, which includes a medicated FET, natural cycle FET (true natural/modified natural), and mild ovarian stimulated FET, along with their scheduling. In addition, it examines whether one FET protocol is superior to another, the relevance of the corpus luteum in medicated vs natural cycle FETs, and optimal progesterone levels.
This post covers the variety of reasons embryos can fail to implant or miscarry, including as a result of advanced maternal age, chromosomal translocations, lifestyle, endometritis, the microbiota, immunological issues, endometrial receptivity, the clinic, and more. Note that this is not a complete list, and will be updated periodically.
This post covers what occurs during normal fertilization and what it means to have an abnormally fertilized zygote (0PN, 1PN, 3PN, 4PN). Using PGT to test these embryos reveals that many have the correct number of chromosome sets and can lead to successful live births.
This post takes a closer look at what “poor-quality” embryos really mean in IVF. At the cleavage stage, they often have fewer cells or high fragmentation, while at the blastocyst stage, a grade C means the inner cell mass and trophectoderm contain fewer, loosely packed cells. These embryos tend to have lower success rates than good-quality ones, but studies show they can have similar perinatal outcomes.
This post discusses the use of supplements to improve egg quality for IVF success, exploring the supporting evidence for a range of supplements like N-acetyl-cysteine, Melatonin, L-arginine, Myo-inositol, CoQ10, L-carnitine, DHEA, folic acid/folate, and vitamins E, C, D, and B.
This post covers mosaic embryos, including their definition, frequency after PGT-A, mosaic embryo levels (low level, high level), mosaic embryo types (whole chromosome, segmental), current guidelines for transfer, potential for self-correction, and success rates.
This post covers PGT-A (formerly called PGS testing), including how it works, how accurate it is, whether it can damage embryos, how to read PGT-A reports, success rates, mosaic embryos, and why even euploid embryos sometimes fail.
Embryo arrest is when an embryo stops developing, usually before reaching the blastocyst stage. This post explains possible causes, including embryonic genome activation, maternal effect genes, the subcortical maternal complex, aneuploidy, mitochondrial dysfunction, oxidative stress, lab conditions, and sperm DNA fragmentation.