X-Message-Number: 22110
From: "Igor Artyuhov" <>
References: <>
Subject: Air dried sperm could allow home storage
Date: Tue, 1 Jul 2003 20:40:31 +0400

Source: EurekAlert 1-Jul-2003
http://www.eurekalert.org/pub_releases/2003-07/esfh-ads062503.ph
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Contact: Emma Mason

44-0-1376-563090
European Society for Human Reproduction and Embryology

Air dried sperm could allow home storage

Madrid, Spain: A novel method of preserving sperm through air
drying is showing initial promise and has the potential to
revolutionize sperm storage, allowing men awaiting in vitro
fertilization (IVF) to take care of their sperm at home.
Dr Daniel Imoedemhe, a consultant in reproductive medicine and
endocrinology, working in Saudi Arabia, told the annual meeting
of the European Society of Human Reproduction and Embryology,
that for the first time studies on human embryos fertilized with
air-dried sperm have shown that the new technique does not
impair the early stages of embryo cell division

Dr Imoedemhe, from Erfan and Bagedo Hospitals, Centre for
Assisted Reproduction, Jeddah, said that in the past it was
believed that sperm "died" when allowed to dry in air because
they were no longer motile and therefore unable to penetrate an
egg. "But with the technique intracytoplasmic sperm injection
(ICSI), the loss of motility doesn't necessarily mean the loss
of ability to fertilize an egg, since this is largely dependent
on the DNA (genetic material) that is tightly packed into the
sperm head. We believe our study confirms that sperm DNA is
resistant to damage by air drying."

Established methods of sperm preservation require special
freezing equipment that needs careful programming to deliver
controlled cooling so that the sperm are not destroyed by
cooling too fast or too slowly. Sperm also need to be stored
with a cryoprotectant (a special chemical that protects sperm
from the adverse effects of cooling to low temperatures), which
then needs to be removed prior to use.

Sperm are stored in large liquid Nitrogen tanks that require
regular top-ups to ensure that they remain in the desired
condition. The tanks are expensive, large and occupy a great
deal of laboratory space. In the current system, in order to
prevent mis-identification during recovery from storage tanks, a
rigorous labelling and coding system is required.

"These methods are time-consuming and cumbersome compared to our
simple technique of air-drying that just requires re-suspension
before use," said Dr Imoedemhe. "The process can be further
simplified by allowing patients to take responsibility for
storing their air-dried sperm at home."

The new air-drying technique involves smearing a sample pellet
of washed sperm on to a glass slide and then leaving it to dry
for two to three hours in a laminar flow cabinet that allows a
directional flow of filtered air to ensure that the sample
remained uncontaminated by airborne dust or micro-organisms. The
dried sperm can then be stored at normal room temperature or in
a normal refrigerator and do not seem to require any other
special storage conditions. Just prior to injection by ICSI into
an egg, the sperm film can be re-suspended with a large drop of
special biological medium (similar to that in which the eggs are
held in order to avoid osmotic changes).

The present study compared early embryos that had been formed
from 24 oocytes subjected to ICSI with re-suspended dried sperm
(the experimental group) with 108 oocytes that that had been
subjected to ICSI with fresh sperm (the therapeutic group). The
study involved nine couples where the eggs taken from wives were
injected with their husband's sperm.

Researchers found that drying did not prevent the sperm from
taking part in the first stages of fertilization that are
considered signs of normal development as 92 % of the eggs
underwent the formation of two pronuclei (microscopically
visible structures can be seen in the egg representing the
genetic contributions from the mother and father) in the egg and
86% developed into cleaved embryos (the early stages of cell
division).

But although drying did not seem to interfere with
fertilization, it was found that 72 hours after sperm injection,
the therapeutic group (eggs fertilized with fresh un-dried
sperms) had significantly more embryos advancing to the eight or
more cell stage than the experimental group (air dried sperm) -
50.5% versus 18.2%.

However Dr Imoedemhe believes this may have more to do with the
differences in experimental procedure necessitated by the
difficulty of acquiring fresh mature eggs for the experimental
group, than the effects of air-drying. In the treatment group
all the eggs were mature (at metaphase II), whereas in the
air-dried group the eggs were immature (at metaphase I) and had
to be matured outside before ICSI. It is thought that such
immature eggs may have less potential for development after
fertilization compared to normally matured eggs.

"We are greatly encouraged that even under these experimental
conditions out of 24 oocytes in the air-dried group, two embryos
developed to the blastocyst stage - this is the last free
floating stage of development before implantation in the uterine
cavity. It's thought that only the best quality embryos can
continue developing outside the body to this stage," he said.

Dr Imoedemhe believes the widespread introduction of air drying
would allow stored sperm to be transported without the need for
specialized equipment, relieve laboratories of the
responsibility of caring for preserved sperm and allow decisions
and responsibilities for disposal to be borne by owners in the
privacy of their own homes.

Storing sperm at home also removes fear of the potential
transmission of HIV and other viral diseases (often expressed by
patients) if samples from infected individuals were stored
inadvertently with those from uninfected people.

Dr Imoedemhe said the next stage is to test the air-drying
technique in mature (metaphase II) eggs to see whether division
happens at the same rate as with fresh sperm and then to carry
out pre-implantation studies on resulting embryos to ensure no
adverse genetic effects have been induced by sperm drying.


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Abstract no: O-178 (Tuesday, 17.30hrs CET, Europa room)

Further information:
Margaret Willson, information officer
Tel: 44-0-1536-772181
Fax: 44-0-1536-772191
Mobile: 44-0-7973-853347
Email: 

Press Office: (Sunday 29 June -Wednesday 2 July)
Margaret Willson, Emma Mason, Maria Maneiro, Janet Bl mli
Tel: 34-917-220-501 or 34-917-220-502
Fax: 34-917-220-503

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