Assisted
reproductive technology (ART)
A collection of
procedures, which includes the handling of gametes and/or embryos outside the
body to achieve a pregnancy, is known as Assisted Reproductive
Technology.
It increases the chance
of pregnancy in infertile couples. ART includes intra-uterine insemination
(IUI), in vitro fertilization, (IVF) Embryo transfer (ET), Zygote
intra-fallopian transfer (ZIFT), Gamete intrafallopian transfer (GIFT),
Intra-cytoplasmic sperm injection (ICSI), Preimplantation genetic diagnosis,
oocyte and sperm donation and surrogacy.
This is a procedure to
treat infertile men with low sperm count. The semen is collected either from
the husband or from a healthy donor and is introduced into the uterus through
the vagina by a catheter after stimulating the ovaries to produce more ova. The
sperms swim towards the fallopian tubes to fertilize the egg, resulting in
normal pregnancy.
In this technique, sperm
and eggs are allowed to unite outside the body in a laboratory. One or more
fertilized eggs may be transferred into the woman’s uterus, where they may
implant in the uterine lining and develop. Excess embryos may be cryopreserved
(frozen) for future use. Initially, IVF was used to treat women with blocked,
damaged, or absent fallopian tubes. Today, IVF is used to treat many causes of
infertility. The basic steps in an IVF treatment cycle are ovarian stimulation,
egg retrieval, fertilization, embryo culture, and embryo transfer.
Egg retrieval is done by
minor surgery under general anesthesia, using ultrasound guide after 34 to 37
hours of hCG (human chorionic gonadotropin) injection. The eggs are prepared
and stripped from the surrounding cells. At the same time, sperm preparation is
done using a special media. After preparing the sperms, the eggs are brought
together. 10,000-1,00,000 motile sperms are needed for each egg. Then the
zygote is allowed to divide to form 8 celled blastomere and then transferred
into the uterus for a successful pregnancy. The transfer of an embryo with more
than 8 blastomeres stage into uterus is called Embryo transfer technique.
As in IVF, the zygote
upto 8 blastomere stage is transferred to the fallopian tube by laparoscopy.
The zygote continues its natural divisions and migrates towards the uterus
where it gets implanted.
Embryo with more than 8
blastomeres is inserted into uterus to complete its further development.
Transfer of an ovum
collected from a donor into the fallopian tube. In this the eggs are collected
from the ovaries and placed with the sperms in one of the fallopian tubes. The
zygote travels toward the uterus and gets implanted in the inner lining of the
uterus.
In this method only one
sperm is injected into the focal point of the egg to fertilize. The sperm is
carefully injected into the cytoplasm of the egg. Fertilization occurs in 75 -
85% of eggs injected with the sperms. The zygote is allowed to divide to form
an 8 celled blastomere and then transferred to the uterus to develop a
protective pregnancy.
Surrogacy is a method of
assisted reproduction or agreement whereby a woman agrees to carry a pregnancy
for another person, who will become the newborn child's parent after birth.
Through in vitro fertilization (IVF), embryos are created in a lab and
are transferred into the surrogate mother's uterus.
Azoospermia is defined
as the absence of spermatozoa in the ejaculate semen on at least two occasions
and is observed approximately in 1% of the population.
Micro-testicular sperm
extraction (TESE) Microsurgical sperm retrieval from the testicle involves a small
midline incision in the scrotum, through which one or both testicles can be
seen. Under the microscope, the seminiferous tubules are dilated and small
amount of testicular tissue in areas of active sperm production are removed and
improved for sperm yield compared to traditional biopsy techniques.
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