Friday, March 20, 2009

IVS: In vitro fertilisation

What is "In vitro fertilisation"?


Initially IVF was developed to overcome infertility due to problems of the fallopian tube, but it turned out that it was successful in many other infertility situations as well. The introduction of intracytoplasmic sperm injection (ICSI) addresses the problem of male infertility to a large extent.
For IVF to be successful it may be easier to say that it requires healthy ova, sperm that can fertilize, and a uterus that can maintain a pregnancy. Due to the costs of the procedure, IVF is generally attempted only after less expensive options have failed.
This means that IVF can be used for females who have already gone through menopause. The donated oocyte can be fertilised in a crucible. If the fertilisation is successful, the zygote will be transferred into the uterus, within which it will develop into an embryo.

Fertilisation

In the laboratory, the identified eggs are stripped of surrounding cells and prepared for fertilization. In the meantime, semen is prepared for fertilization by removing inactive cells and seminal fluid. 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 has reached the 6-8 cell stage.

Embryo- Oocyte Donation

The first transfer of an embryo from one human to another resulting in pregnancy was reported in July 1983 and subsequently led to the announcement of the first human birth February 3, 1984.It was accomplished by in vivo fertilisation, a process that was derived from animal husbandry. This procedure was performed at the Harbor UCLA Medical Center under the direction of Dr.John Buster and the University of California at Los Angeles School of Medicine.

In the procedure, an embryo that was just beginning to develop was transferred from one woman in whom it had been conceived by artificial insemination to another woman who gave birth to the infant 38 weeks later. The sperm used in the artificial insemination came from the husband of the woman who bore the baby.
Donor embryo transfer has given women a mechanism to become pregnant and give birth to a child that will contain their husband’s genetic makeup. Although donor embryo transfer as practiced today has evolved from the original non-surgical method, it now accounts for approximately 5% of in vitro fertilization recorded births.

Prior to this, women who were infertile, had adoption as the only path to parenthood. This set the stage to allow open and candid discussion of embryo donation and transfer. This breakthrough has given way to the donation of human embryos as a common practice similar to other donations such as blood and major organ donations. At the time of this announcement the event was captured by major news carriers and fueled healthy debate and discussion on this practice which impacted the future of reproductive medicine by creating a platform for further advancements in woman's health.

This work established the technical foundation and legal-ethical framework surrounding the clinical use of human oocyte and embryo donation, now a mainstream clinical practice that has evolved over the past 25 years. 

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