Sunday, April 4, 2010

IVF Info

There is a ton of information about IVF on the internet both from a sales and marketing angle, as well as, chat rooms and posting boards. I have exhausted the sales/marketing sites, since they all say about the same thing and limit myself to 15 minutes per day on the chat rooms/posting boards since it can be really overwhelming.

I personally think that Wikipedia has an excellent entry about IVF, but from a British perspective, so the word spelling is a bit different. Here is the whole
entry.

Here is the IVF overview section that gives the step-by-step information about the IVF process:

Ovarian stimulation
Treatment cycles are typically started on the third day of menstruation and consist of a regimen of fertility medications to stimulate the development of multiple follicles of the ovaries. In most patients injectable gonadotropins (usually FSH analogues) are used under close monitoring. Such monitoring frequently checks the estradiol level and, by means of gynecologic ultrasonography, follicular growth. Typically approximately 10 days of injections will be necessary. Spontaneous ovulation during the cycle is typically prevented by the use of GnRH agonists that are started prior or at the time of stimulation or GnRH antagonists that are used just during the last days of stimulation; both agents block the natural surge of luteinising hormone (LH) and allow the physician to initiate the ovulation process by using medication, usually injectable human chorionic gonadotropins.

Egg retrieval
When follicular maturation is judged to be adequate, human chorionic gonadotropin (hCG) is given. This agent, which acts as an analogue of luteinising hormone, would cause ovulation about 42 hours after injection, but a retrieval procedure takes place just prior to that, in order to recover the egg cells from the ovary. The eggs are retrieved from the patient using a transvaginal technique involving an ultrasound-guided needle piercing the vaginal wall to reach the ovaries. Through this needle follicles can be aspirated, and the follicular fluid is handed to the IVF laboratory to identify ova. It is common to remove between ten and thirty eggs. The retrieval procedure takes about 20 minutes and is usually done under conscious sedation or general anaesthesia.

Fertilisation
In the laboratory, the identified eggs are stripped of surrounding cells and prepared for fertilisation. In the meantime, semen is prepared for fertilisation by removing inactive cells and seminal fluid in a process called sperm washing. If semen is being provided by a sperm donor, it will usually have been prepared for treatment before being frozen and quarantined, and it will be thawed ready for use. The sperm and the egg are incubated together at a ratio of about 75,000:1 in the culture media for about 18 hours. In most cases, the egg will be fertilised by that time and the fertilised egg will show two pronuclei. In certain situations, such as low sperm count or motility, a single sperm may be injected directly into the egg using intracytoplasmic sperm injection (ICSI). The fertilised egg is passed to a special growth medium and left for about 48 hours until the egg consists of six to eight cells.
In gamete intrafallopian transfer, eggs are removed from the woman and placed in one of the fallopian tubes, along with the man's sperm. This allows fertilisation to take place inside the woman's body. Therefore, this variation is actually an in vivo fertilisation, not an in vitro fertilisation.

Culture and selection
Laboratories have developed grading methods to judge oocyte and embryo quality. Typically, embryos that have reached the 6–8 cell stage are transferred three days after retrieval. In many Canadian, American and Australian programmes, however, embryos are placed into an extended culture system with a transfer done at the blastocyst stage at around five days after retrieval, especially if many good-quality embryos are still available on day 3. Blastocyst stage transfers have been shown to result in higher pregnancy rates.In Europe, transfers after 2 days are common. Preimplantation Genetic Diagnosis (PGD) procedures may be performed prior to transfer. Culture of embryos can either be performed in an artificial culture medium or in an autologous endometrial coculture (on top of a layer of cells from the woman's own uterine lining). With artificial culture medium, there can either be the same culture medium throughout the period, or a sequential system can be used, in which the embryo is sequentially placed in different media. For example, when culturing to the blastocyst stage, one medium may be used for culture to day 3, and a second medium is used for culture thereafter.[3] Single or sequential medium are equally effective for the culture of human embryos to the blastocyst stage. Artificial embryo culture media basically contain glucose, pyruvate, and energy-providing components, but addition of amino acids, nucleotides, vitamins, and cholesterol improve the performance of embryonic growth and development.

Embryo transfer
Embryos are graded by the embryologist based on the number of cells, evenness of growth and degree of fragmentation. The number to be transferred depends on the number available, the age of the woman and other health and diagnostic factors. In countries such as Canada, the UK, Australia and New Zealand, a maximum of two embryos are transferred except in unusual circumstances. In the UK and according to HFEA regulations, a woman over 40 may have up to three embryos transferred, whereas in the USA, younger women may have many embryos transferred based on individual fertility diagnosis. Most clinics and country regulatory bodies seek to minimise the risk of pregnancies carrying multiples. The embryos judged to be the "best" are transferred to the patient's uterus through a thin, plastic catheter, which goes through her vagina and cervix. Several embryos may be passed into the uterus to improve chances of implantation and pregnancy.

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