in-vitro fertilization (IVF)
The use of artificial techniques that join an ovum
with sperm outside the woman's body to help
some infertile couples to have children of their own. The basic technique
of IVF involves removing ova from a woman's ovary,
fertilizing them in the laboratory, and then inserting them into the woman's
|The mother, or egg donor, is given hormone treatment
to cause many ovarian follicles to develop (1). While the ovary is
observed through a laparoscope, a long needle (2) is inserted into
each follicle , which is then sucked up (3) and transferred to a petri
dish where sperm are added (4). The cells are monitored under a microscope.
As the zygote (5) divides to a stage where it consists of 16 cells,
it is introduced into the mother's uterus through a long plastic tube
so that it can implant in the wall (6) and progress to full term in
the usual way.
In zygote intrafallopian transfer (ZIFT),
a fertilized ovum (zygote) is returned to the Fallopian
tube, from where it makes its way to the uterus. In gamete
intrafallopian transfer (GIFT), the ova are removed, mixed with sperm, then
both ova and sperm are inserted into a Fallopian tube to be fertilized in
the natural setting. These IVF procedures result in live births in up to
20% of cases.
The worlds first "test-tube baby" was born in Britain in 1978.