PATIENT FACT SHEET from ASRM (American Society for Reproductive Medicine)
Sperm Shape (Morphology): Does It Affect Fertility?
How do doctors decide if a man might have a fertility
For many years, experts have focused on semen analysis, but research studies show that the number of sperm (count) and the movement of sperm (motility) do not always predict fertility very well by themselves.
It may also be useful to look at the shape of the sperm (morphology),
which is also one of the important parts of the semen evaluation.
An updated way of determining sperm shape is called the
Kruger's strict morphology method. Kruger morphology is
a useful system that helps doctors determine if a sperm is
normally shaped or not. It was originally used to predict
the success of in vitro fertilization (IVF), a fertility treatment
in which the sperm are mixed with the woman's egg
in a laboratory.
More recently, it has been used to tell if
intracytoplasmic sperm injection (ICSI) is a necessary
treatment. ICSI is a procedure that helps a sperm fertilize
an egg by injecting a single sperm directly into the center
of the egg.
Even though it is used for these purposes, not all physicians
and scientists are sure that strict morphology method alone
predicts success with IVF or whether it indicates the need
Characteristics of normal sperm
A normal sperm has:
• a smooth, oval shaped head that is 5-6 micrometers long
and 2.5-3.5 micrometers around (less than the size of a
• a well defined cap (acrosome) that covers 40% to 70% of
the sperm head
• no visible defect of neck, midpiece, or tail
• no fluid droplets in the sperm head that are bigger than
one-half of the sperm head size
Intercourse versus artificial insemination
For patients with fertility problems, sperm morphology may have an effect on your ability to achieve a pregnancy. If the strict sperm morphology is more than 4%, there may be little difference in success whether timed intercourse or artificial insemination is utilized.
A successful pregnancy using IVF depends on many of
factors: how many eggs are fertilized, whether the fertilized
eggs grow into embryos, and whether the embryo implants
in the woman's uterus. When strict morphology is 4% or
less, eggs may have a better chance of fertilization with the
use of ICSI.
Frequently asked questions
If an abnormally shaped sperm fertilizes the egg, does
that mean that my child will have genetic abnormalities?
There's no scientific link between the shape of a sperm and
its chromosomal content. Once the sperm penetrates the
egg, fertilization has a good chance of taking place.
However, there may be some male offspring who will
inherit the same type of morphology abnormalities.
Whether routine investigation of Y-chromosome abnormalities
should be initiated when low morphology is noted is
Are there any substances that I can reduce or eliminate
exposure to (e.g., alcohol, tobacco, caffeine) in order to
improve the shape of my sperm?
Studies haven't shown a clear link between abnormal sperm
shape and these factors, but it's a good idea to try to eliminate
use of tobacco and recreational drugs and limit your
consumption of alcohol. These substances reduce sperm
production and function in several ways. They may hurt
sperm DNA (material that carries your genes) quality.
Studies have not shown a clear link between caffeine consumption
and changes in sperm shape.
Are there any dietary supplements or vitamins that I
can take to improve morphology?
Dietary supplements or vitamins have not been clearly
shown to improve sperm morphology. Some specialists do
recommend that you take a daily multivitamin to improve a
number of body functions, including reproductive health.
The American Society for Reproductive Medicine grants permission to photocopy this fact sheet and distribute it to patients.
Today’s the day that we celebrate Martin Luther King Jr.’s birthday. It’s not actually his birthday but we celebrate today. Today is actually my younger sister’s birthday.
And don’t try to convince her that this federal holiday and many people being off today is not actually about her; she won’t believe you.
My younger sister is only 18 months younger than I am. Still, she was my baby sister all through the years that we were growing up. It is reported, by my mother, that she delayed going to the hospital to have her so that my mother could finish reading my older sister and me a story. It is also, reported by my mother, that I took one look at my younger sister and told my mother to throw her in the garbage.
At first glance, this is certainly not a story about a family and infertility. Clearly, my mother had three children, how does fertility come into play here? Scratch a little under the surface and you see different things. My older sister was born with a genetic disease. Fifty plus years ago, no one even knew it was a genetic disease. My family of doctors, nurses and geneticists, luckily did not know that any child my parents would have had a %50 possibility of inheriting that disease. The medical community didn’t discover that for almost twenty more years.
Luckily for my younger sister and me, we did not inherit the disease. Even so, when I decided to have children, I went through rigorous testing to determine whether I was a carrier. It would be another five years before the gene was isolated and “discovered” and then we would have known that if I didn’t have the disease, I couldn’t carry it or pass it on. I worried while I was trying to conceive and in some senses those first few years of infertility and fertility treatment bought me relief, as that was the time needed for the gene to be discovered. The last few years in treatment I did know that if I conceived I would not be passing on that particular disease.
In the twenty plus years that I have been active in the field of infertility, I have seen miraculous things. I would count the ability to cyropreserve embryos, the technique of ICSI ( Intracytoplasmic Sperm Injection), PGD (Pre-implantation diagnosis) and now Comprehensive Chromosomal Screening (CCS) among the largest and most important breakthroughs of those years. CCS, a way of looking at embryos and determining that all of the chromosomes are healthy, brings tears to my eyes. Given the high miscarriage rate in the first trimester due to chromosomal abnormality, knowing that healthy embryos are being transferred, brings a peace of mind that has never existed to those of us in treatment.
For me, my family was lucky. My oldest sister has borne the brunt of the disease that she inherited, with grace and strength. She is inspiring and always has been. She is also in a lot of pain, all the time and has had a lifetime in pain and difficulty. My younger sister and I, as has everyone in our family, have been affected, of course. We were affected on many different levels, including a feeling of relief that we have not been affected by this disease. And guilt that it was my oldest sister and not either of us.
So yes, our family was lucky that this disease only struck one out of three of us. With CCS, my older sister would not have this disease, nor would she have had such a difficult, painful life. In my intimate world, that is progress. I wish that CCS had been around when she was conceived; her life could have been so different.
My happy birthday wishes go out to my younger sister; so happy that my mother did not take my advice about throwing her away. So lucky too, that she was born healthy!
Male factor infertility accounts for about 40% of trouble in conceiving. Read below for one of the most reliable and significant ways that a reproductive endocrinologist can work with a male factor problem.
Treating Male Factor Infertility with ICSI and IVF
Intracytoplasmic Sperm Injection (ICSI) is a process of micromanipulation that is used to treat severe forms of male infertility.
With this technique, the embryologist injects a single sperm into the center of each egg retrieved as part of the in vitro fertilization (IVF) cycle. The sperm may be either 'washed' or 'unwashed' for the intracytoplasmic sperm injection.The fertilized egg grows in a laboratory. After five days, the egg is placed in the woman's womb.
With ICSI, an egg can be fertilized by a single sperm that otherwise would be unable to penetrate the zona pellucida (the permeable barrier around the egg) and bind to the egg. Once fertilization takes place, a couple's chance of giving birth to a single baby, twins, or triplets is the same if they have IVF with or without ICSI.
When is IVF with ICSI Implemented?
For the most part ICSI with IVF is used in cases of male factor infertility.
ICSI is offered to men:
- Whose sperm with severe abnormalities
- Whose sperm has failed to fertilize eggs in previous IVF cycles
- Who have congenital or acquired absence or obstructions of the ejaculatory ducts
- Who have had unsuccessful vasectomy reversals
- With spinal cord injuries or pituitary deficiencies.
ICSI is used to counter a female infertility factor when a woman produces:
- A lower number of eggs
- Low quality eggs
- Both low quality and a low number
For more information about intracytoplasmic sperm injection (ICSI), please contact us.
ICSI is a method that has been used for many years and has helped many people achieve pregnancies. If male factor is a problem for you, then this may be a solution that you can look into.
Any questions about ICSI? Our doctors at Reproductive Medicine Associates of Connecticut will be happy to answer!