In vitro fertilization and embryo transfer in humans
Infertility is a common and serious problem
in reproduction now-a-days. Animal culture
and tissue techniques provide a solution to
this problem through the techniques of IVF
and Embryo Transfer (ET).
Invitro fertilization( IVF) refers to the union
between egg cell and sperm outside body in a
culture vessel involving their collection and
fusion under appropriate conditions in vitro
to give rise to zygotes which are cultured in
vitro to obtain young embryos.
The implantation of young embryos
developed in vitro or obtained from the
uterus of females into the womb of selected
females is termed as Embryo Transplantation
or Embryo Transfer.
Collection of oocytes
Collection of sperms
IVF of the oocytes
Implantation of the resulting zygotes in the
Collected from females desirable of having
Cannot be collected from females with non-
Can be collected during a natural or induced
Time for this is determined by monitoring
rise in the level of Luteinizing Hormone(LH) in
urine or blood.
Ovulation may be stimulated by administration of
Clomiphene or Human menopausal Gonadotropin
Follicle development maybe arrested at the
optimum stage by administering Human
chorionic gonadotropin (hCG) so that ova are not
Recovery of oocytes can be done most
conveniently by a laparoscopic instrument that
allows the visualization of ovary through a
monitor, aspiration (suction) of the follicular fluid
containing the oocytes and the necessary surgical
manipulation of ovary using sensors, laproscopic
scissors and an aspirating apparatus inserted
into the abdomen of the female via a suitable
Collected about 60-90 minutes prior to
fertilization, liquefied and centrifuged.
Resuspended in culture medium, and
incubated for 30-60 mins at 37⁰ C.
The most active sperms are located in the
surface of the medium.
If sperm collection from the prospective
father is not possible due to Oligospermia or
Azoospermia, semen is collected from a
Fig. Procedure of collection, Centrifugation
and Suspension of sperms in culture medium
Oocytes are identified by microscopic
examination of the follicular fluid aspirated
during laparoscopy, and are incubated for
10-15 hours depending upon the expected
time of maturation.
Following mediums maybe used for serving
1. Modification of Ham’s F10 medium
2. Earl’s solution
3. Modified Whitten’s medium
4. Whittingham’s T6 medium
All these media has the following in common-
Utilizes a bicarbonate/CO2 buffer system to
keep PH in the range of 7.2-7.4.
Osmolarity range of 275-290 osmol/kg.
Temperature setting of 37.0-37.5°C
Cultured under paraffin oil, which prevents
evaporation of the medium preserving a
constant Osmolarity and minimizes
fluctuations of pH and temperature.
Media must have 99% water,.
Albumin or synthetic serum in concentrations
of 5 to 20% w/w or v/v as protein source.
Carbohydrates- Pyruvate, lactate and high
conc. of glucose.
Amino acids- all 20 amino acids.
Salt solutions- NaCl, KCl, KH₂PO₄ etc.
Antibiotics- Penicillin, Streptomycin etc.
Chelators like EDTA to prevent abnormal
Fertilization is started by adding 10,000-
50,000 motile sperms to about 100 µl to 1 ml
culture medium in which the oocytes is being
The oocytes is examined after 12-13 hrs for
detection of –
1. Number of pronuclei and polar bodies
2. Granulation of the oocytes and
3. Shape of the oocytes
A normally fertilized oocyte (actually a zygote
now) contains two pronuclei and two
polar bodies. Any zygote other than this and
having abnormalities and granulation of any
kind are rejected.
The first division in the zygote occurs about
24-30 hrs after insemination, but each
subsequent division takes about 10-12 hrs.
Therefore, if an oocyte fails to divide by 30
hrs after insemination, it should not be used
Fig. Different stages of development of a blastocyte
The patient is orally administered with Valium
before embryo transfer.
The whole process is negotiated through
The patient is placed in lithotomy (knee
A sterile bivalve speculum is inserted to
visualize the cervix.
The cervical canal and uterine cavity are
The embryo is drawn into a Teflon catheter in
tissue culture medium. Teflon is used due to
its low adhesiveness.
The catheter is inserted into the uterine cavity
just short of the fundus.
The embryo is gently inserted in culture
medium and the catheter and cannula are
Catheter is examined under the microscope
to ensure that the embryo has been expelled.
The babies produced using these approaches
are called test tube babies.
The first test tube baby was born on July
25, 1978 and was named Louise Joy Brown.
The Nobel Prize of Medicine for the year 2010
was awarded to Robert G. Edwards for this
Fig. Louise Brown with her parents Fig. Robert G. Edwards with Louise
IVF success rates are the percentage of all IVF
procedures which result in a favourable
outcome, which implies Pregnancy rate
(Number of confirmed pregnancies) or Live
birth rate (Number of live births).
Due to advancement in reproductive
technology, the IVF success rates are
substantially better today than they were just
a few years ago.
Duration of infertility or sub-fertility
Number of oocytes
High body mass index
Pre-implantation genetic screening or
diagnosis (PGS or PGD)-
Preimplantation genetic screening (PGS) or
preimplantation genetic diagnosis (PGD) has
been suggested to be able to be used in IVF
to select an embryo that appears to have the
greatest chances for successful pregnancy.
Embryo splitting- It can be used for twinning
to increase the number of available embryos.
Intra cytoplasmic sperm injection- It is
an invitro fertilization procedure in which a
single sperm is injected directly into an egg.
Assisted zona hatching- Assisted zona
hatching (AZH) is a procedure of assisted
reproductive technology in which a small hole
is made in the zona pellucida, using a
micromanipulation, thereby facilitating
for zona hatching to occur. Zona hatching is
where the blastocyst gets rid of the
surrounding zona pellucida to be able to
implant in the uterus.
Laboratory mix-ups (misidentified
gametes, transfer of wrong embryos) have
occurred, leading to legal action against the
IVF provider and complex paternity suits.
An example is the case of a woman in
California who received the embryo of
another couple and was notified of this
mistake after the birth of her son.
This has led to many authorities and
individual clinics implementing procedures to
minimise the risk of such mix-ups.
The Catholic Church opposes all kinds of in
vitro fertilisation because, as with contraception, it
separates the procreative purpose of the marriage act
from its unitive purpose, i.e. to produce a new life.
Another concern is that people will screen in or out
for particular traits.
A deaf British couple have petitioned to create a deaf
baby using IVF. Medical ethicists are against this form
of Pre-implantation genetic screening or diagnosis as
“intentionally culling out blind or deaf embryos might
prevent considerable future suffering, while a policy
that allowed deaf or blind parents to select for such
traits intentionally would be far more troublesome.”
Elements of Biotechnology by P.K. Gupta;
Biotechnology Expanding Horizons by B.D.