2014 Conference Melbourne, Australia Embryology 101 Basics of embryo development in an IVF...
Embed Size (px)
Transcript of 2014 Conference Melbourne, Australia Embryology 101 Basics of embryo development in an IVF...
- Slide 1
2014 Conference Melbourne, Australia Embryology 101 Basics of embryo development in an IVF laboratory. Dr. Samit Sekhar Executive Director and Embryologist Kiran Infertility Centre Pvt. Ltd Slide 2 2014 Conference Melbourne, Australia Embryology in Greek means "the unborn, embryo) is the science of the development of an embryo from the fertilization of the ovum to the fetus stage.embryofertilizationovumfetus In a routine ART (Assisted reproductive Technology) setting we create embryos by fusing sperm from the male partner with the egg of the female partner. Slide 3 2014 Conference Melbourne, Australia In vitro fertilisation (IVF) commonly known as test tube baby as we all know is one of the most significant advances in the field of modern medicine. The first IVF baby Louis Brown, born in England in 1978 was the result of more than a decade of research by Dr. Patrick Steptoe and Robert Edwards. They essentially changed the rules for how people can come into the world. Conception was now possible outside the body in a petri dish. The technique has resulted in the births of millions of babies worldwide, many in multiple births. Treatment Option 1 Slide 4 2014 Conference Melbourne, Australia Initially ivf was developed for women with tubal disease but now it is the treatment of choice for several other causes of infertility,since its introduction all the steps of ivf have been improved upon which has resulted in continuously rising success rates. IVF has also provided a platform for the development of other treatments including egg donation, Gestational surrogacy and preimplantation diagnosis Slide 5 2014 Conference Melbourne, Australia Steps of IVF 1. Ovulation Induction is as per the protocols based on several factors of the female partner and might be a Down regulated or Antagonist cycles. 2. Oocyte retrieval is performed under vaginal ultrasound guidance. After the vaginal ultrasound is placed in the vagina and the ovarian follicles are located a needle is directd through the back wall of the vagina and directed into the ovarian follicles. The fluid is aspirated and then examined by the embryologist to identify the microscopic egg - oocyte surrounded by granulosa cells (cumulus). During normal fertilisation the acrosome of the sperm releases enzymes which disperse the cumulus cells thereby allowing the sperm to penetrate and fertilise the oocyte. Once the eggs are retrieved they are placed in culture media with added nutrients and then placed in the incubator. The procedure is performed under a general Anesthesia and generally takes less than 10 to 15 minutes to complete. There are minimal complications(10% of the embryo surface. Slide 16 2014 Conference Melbourne, Australia A clear homogeneous cytoplasm is a sign of normal cleavage stage embryo. The presence of multiple vacuoles is a sign of a poor quality embryos Compaction- After the embryo reaches the 8-cell stage, the blastomeres begin to show an increase in cell to cell adherence and this is known as compaction and the process continues until the boundaries between the cells are barely detectable. If some of the blastomeres are excluded from this compaction process, the embryo may have a reduced potential for becoming a normal blastocyst Compaction Slide 17 2014 Conference Melbourne, Australia Blastocyst transfer Day 5 or day 6 embryos are called blastocyst stage embryos. The blastocyst stage is the stage of development that an embryo must reach before it can hatch and implant in the uterus Blastocyst embryos consists of a blastocoel which causes the embryo to start to expand and increase in overall size. Blastocyst embryos have two distinct parts, the inner cell mass (these cells develop and become the fetus), and the trophectoderm cells (these cells will develop into the placenta). The blastocyst is given a grade based upon the three main components of the blastocyst embryo. Slide 18 2014 Conference Melbourne, Australia Expansion Grade 1.Early Blastocyst: the blastocoel filling more than the volume of the embryo, but not expansion in overall size compared to earlier stages. 2.Blastocyst: the blastocoel filling more than the volume of the embryo, with slight expansion in overall size and notable thinning of the zona. 3.Full Blastocyst: a blastocoel filling more than 50% of the embryo volume and overall size fully enlarged with a very thin zona. 4.Hatching Blastocyst: The trophectoderm has started to herniate through the zona. 5.Fully Hatched Blastocyst: Free blastocyst fully removed from the zona. Slide 19 2014 Conference Melbourne, Australia Inner Cell Mass A Tightly packed compacted cells. B Large, loose cells C No ICM distinguishable D Cells of the inner cell mass appear degenerative Trophectoderm Grade A Many healthy cells forming a cohesive epithelium B Few but healthy cells, large in size C Poor, unevenly distributed cells. Many appear as few cells squeezed to the side D Cells of the trophectoderm appear degenerative embryo surface. Hatching Blastocyst Slide 20 2014 Conference Melbourne, Australia Embryo freezing Step 1. consent Step 2. Screening for both people who provided the eggs and sperm used to create the embryos for infectious diseases such as HIV, Hepatitis B & C. Step 3. During treatment, the unused embryos are frozen and then stored in tanks of liquid nitrogen. A liquid called a cryoprotectant is added to protect the embryos during freezing. In the standard freezing method, embryos are slowly frozen down to -196 degrees celcius. vitrification. is a fast freeze process the embryo undergoes instantaneous glass-like solidification without the damaging formation of ice crystals (which can occur with the standard method of freeze) Slide 21 2014 Conference Melbourne, Australia How long can the embryos be stored? The normal maximum period that frozen embryos can be stored is ten years. This may be extended depending on the medical circumstances of the woman undergoing treatment, her partner and/or a donor. Slide 22 2014 Conference Melbourne, Australia Slide 23 Slide 24