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IVF and ICSI: Is Less Actually More?

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IVF and ICSI: Is Less Actually More?

It is the
single biggest advance in fertility technology since in vitro fertilization (IVF) was
developed 40 years ago. It helps men with even the most severe
forms of infertility to father children. It allows human eggs to begin life
when they would not have otherwise done so. And it’s used in the vast majority
of cases of IVF nowadays. But what has taken the fertility industry by storm
started out as a lab error. It also bypasses natural selection as we know it.
Welcome to the world of single sperm injection or intracytoplasmic sperm
injection (ICSI).

Double-Edged
Sword

ICSI was
born from the need to enable men with male infertility and low sperm counts to
conceive. IVF requires a few million sperm to “bath” eggs in a dish. But if
fewer sperm are available, IVF won’t work. Adding ICSI to IVF reduces the sperm
requirement to 1 sperm per egg, as a single sperm is injected directly into the
egg. Notably, with IVF, nature still chooses the best sperm for fertilization,
but with ICSI a laboratory embryologist chooses the sperm. I’ve always wondered
whether we are as good as God or Darwin at selecting the right sperm. We know
natural selection, developed through millions of years of evolution, is altered
with ICSI, and in ways that are entirely unclear to us. So, although ICSI is a
powerful sword, it is also a double
edged
 one. It is, in a word, somewhat “unnatural.”

ICSI
Overkill?

ICSI began
as a tool to help men with male infertility, which is about 15% of
IVF cases. Lately, however, it has been used in the vast majority (75%)
of IVF cases and for reasons entirely unrelated to male infertility. Is our
encroachment into nature’s turf warranted? Is ICSI really helping us conceive
better than IVF alone?

Recently, a study was done in Australia to examine this
issue. Researchers looked at 3363 IVF cycles over a 6-year period
that were undertaken in couples without any male factor
infertility. That means that the male partners had normal semen analyses. But
ICSI was used along with IVF anyway. They then compared the outcomes of couples
who used IVF and those who underwent IVF-ICSI. By all measures of success, the
couples receiving IVF did better. This includes fertilization rates (5%
better
), pregnancy rates (6% better) and live birth rates (4%
better
). Although these differences appear small, they are highly
clinically and statistically significant. In fact, the authors concluded that
“this translates to 1 less pregnancy for every 15 cycles where
ICSI was used without [a] clear indication.” So, the addition of more
technology led to less fertility success.

So, what’s
the lesson? Nature has been tweaking reproduction over millions of years and
it’s quite good at it. Maybe we shouldn’t assume that our newly developed
technology is better than nature in all cases. Maybe we should use fertility
technology only when we really need it and go more “organic” with fertility
treatments!

This article first appeared on Dr.
Turek’s blog
.

Image by Elena Έλενα Kontogianni Κοντογιάννη from Pixabay

Author: Dr. Paul Turek, Medical Contributor

Dr. Paul Turek is an internationally known thought leader in men’s reproductive and sexual health care and research. A fellowship trained, board-certified physician by the American Board of Urology (ABU), he has received numerous honors and awards for his work and is an active member in professional associations worldwide. His recent lectures, publications and book titles can be found in his curriculum vitae.



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