PartⅢ Script of the Audiovisual Material
How IVF Works
The technique of in vitro fertilization or IVF removes several eggs from the ovary for fertilization in the laboratory.After a few days,one or two of these fertilized eggs which are now known as embryos are returned to the uterus in the hope that they implant and become pregnancy.Women having an IVF are given special reproductive hormones to encourage several eggs to develop in the ovaries.Final maturation and the egg itself is induced by administering further hormones.Thirty-six hours later,fluid containing the egg is drawn from the ovary with a needle.This is usually performed under the light sedation in the short outpatient procedure with the doctor using ultrasound to check the proceedings.
The menstrual cycle of the fertile women usually lasts about a month.During this time and under the influence of the body's own natural hormones,a tiny sac within the ovary containing an egg grows to about the size of a grain.At the point mid-way of the cycle,this egg is released from the ovary and ovulation occurs.Ovulation is also regulated by hormones.The egg which,from this moment on,is ready for fertilization,then passes into the uterine tube to await the arrival of the fertile sperms.Ovulation is a naturally occurring event,and the desire to have children is similarly a natural instinct.But that instinct cannot always be fulfilled.The causes of unwanted childlessness are numerous,and so are the means to treat them.(https://www.daowen.com)
The eggs collected from the ovaries are then mixed with some of the male partner's sperm which is already washed and concentrated.The eggs and sperm are left in the incubator at set 37 degrees for 24 hours so that fertilization can take place.During this time,only one of the many sperm cells w ill penetrate the outlay of the egg to achieve fertilization.Follow ing fertilization,this cell divides,multiplies,and forms the embryo.After two or three days,a healthy embryo w ill comprise around 8 cells.It is then transferred to the uterus by means of a thin flexible tube,where it is left implant and form pregnancy.
All these methods of the assisted reproduction offer a couple a good chance of bringing their healthy baby into the world.A consultation and thorough examination are necessary for each individual patient for finding the most appropriate treatment w ith the highest chance of success.Because female fertility decreases quite quickly after the age of 35,infertile couples should not delay seeking the appropriatemedical advice.