(orchestral music)
- [Narrator] In vitro fertilization is a process
where a woman's eggs are fertilized outside her body
then placed back inside her body to help her get pregnant.
A woman's reproductive system includes the vagina,
cervix,
uterus,
fallopian tubes,
and ovaries.
During the monthly menstrual cycle,
one of the ovaries releases an egg
in a process called ovulation.
After ovulation, the egg enters the fallopian tube.
A woman is most likely to become pregnant
if she has sex in the days just before,
during, or right after ovulation.
During this time,
a sperm cell from a man's reproductive fluid called semen
is able to fertilize the egg just inside the fallopian tube.
As it travels along the fallopian tube,
the fertilized egg, now called an embryo,
loses the outer cells that nourished it in the ovary.
The embryo passes from the fallopian tube into the uterus.
In the uterus, the embryo sheds its protective outer layer
called the zona pellucida in a process called zona hatching.
Zona hatching is necessary for the embryo
to implant in the tissue lining the uterus.
During implantation,
a connection between the woman and the embryo
begins to grow.
This organ, called the placenta,
allows oxygen and nutrients to pass from her to the embryo.
In vitro fertilization may be performed
if a woman has been having trouble getting pregnant,
a condition known as infertility,
or it may be done if a woman wants to have a child
without a male partner.
Before in vitro fertilization,
a woman will receive fertility medication
that causes more than one egg
to grow and mature in the ovaries.
A man will provide a semen sample
so that the healthiest sperm
can be collected for fertilization.
If the male partner is completely infertile,
also known as sterile,
or the woman doesn't have a male partner,
a donor may be arranged to provide sperm for this process.
In vitro fertilization consists of three main procedures:
follicle aspiration,
fertilization,
and embryo transfer.
During the first procedure, called follicle aspiration,
eggs will be harvested from the ovaries.
At the beginning of this procedure,
an ultrasound probe will be inserted into the woman's vagina
so that her doctor can view her ovaries.
Inside the ovaries, the doctor will look for follicles.
Each follicle is a fluid-filled sac that contains an egg.
Then the doctor will insert a long thin needle
into and through the wall of her vagina
and guide it to the ovary.
A suction device connected to the needle
will collect several eggs from inside their follicles.
During the second part of in vitro fertilization,
called fertilization,
the collected eggs will be taken
immediately to a laboratory where they will be fertilized.
Fertilization may be performed by insemination,
where several sperm are mixed with the healthiest eggs.
Or the eggs may be fertilized with sperm
injected directly into them
during a process called intracytoplasmic sperm injection.
The fertilized eggs, also called embryos,
will be monitored for three to five days
as they begin to grow.
At this time, the lab may create a hole
in the zona pellucida surrounding some of the embryos.
This process called assisted hatching
will help these embryos implant in the uterus.
Some of the embryos will be used right away
for embryo transfer, and the rest will be frozen and stored
for future use if necessary.
The third part of in vitro fertilization
is called embryo transfer,
which is done three to five days after fertilization.
During embryo transfer, a tool called a speculum
will be inserted into the woman's vagina
so that the doctor can see her cervix.
A syringe will be loaded with fluid
containing one or more of the hatched embryos.
Then the syringe will be attached
to a long thin tube called a catheter.
The doctor will insert the catheter into the vagina
through the cervix and into the uterus.
Once inside the uterus, the doctor will inject the embryos.
Then the catheter and speculum will be removed.
The woman may continue to lie on her back
for about 15 minutes.