A male’s sperm health is very important for conception and a successful pregnancy. Now, you might have heard of sperm count. Are you aware of sperm morphology? Which is more important for conception - sperm count or sperm quality? Read on to find out.
The human sperm consists of the head, midpiece, and tail. The head of the sperm is oval in shape, and the tail known as the flagellum is long and thin. The sperm head has a cap that protects and covers about 40% – 70% of the head. This sperm cap contains enzymes and is also responsible for penetrating the egg. After penetration, the sperm’s nucleus will join the egg nucleus and fertilisation begins.
If the sperm shape is different, it can affect the ability of the sperm to penetrate the egg, thus interfering with conception. It is normal for some sperm to be of irregular shape or have some deformities. As long as the irregular sperm is only a small percentage of the ejaculated semen, it may not affect the sperm’s ability to fertilise the egg.
The fertility specialist will collect a semen sample from the male partner and take a close look at the same, under the microscope. If the sperm's shape and movement seem normal, then the sperm is healthy.
Every male will carry a small percentage of sperm in irregular shape or size. According to the WHO, if a semen sample contains 4% or more sperm with normal morphology, it is sufficient for fertility. The head of the sperm contains the DNA material and 23 chromosomes from the father. The following factors are crucial for sperm morphology –
● The sperm head is about 6 micrometres long and 2.5 – 3.5 micrometres wide
● The cap should cover no more than 70% of the sperm head
● Droplets of fluid on the head, if any should not be more than half the sperm size.
● The midsection and tail of the sperm should be free of any abnormal structures.
● DNA content in the sperm head – it is assessed by the nuclear colour stain
Sperm count refers to the number of sperm present per millilitres of semen. An average sperm count is more than 15 million sperm in one milliliter of semen. If it is lower than 15 million, it is known as a low sperm count. If it is less than 5 million per mL of semen, it is known as severely low sperm count.
A semen analysis will measure various characteristics of the sperm and semen. When it comes to sperm count, the technician will check both sperm count and concentration.
● Sperm concentration shows how close together the sperm are in the semen sample.
● Oligospermia is a condition where a male’s sperm count is less than 15 million per mL of semen.
● Azoospermia is a condition when there is no sperm in the ejaculation.
Some important factors of semen that impact male fertility are:
● Total sperm count
● Sperm concentration (no of sperm present per mL of semen)
● Percentage of live sperm
● Sperm motility
● Semen volume per ejaculation
So, what has a higher correlation? Sperm count and fertility or sperm morphology and fertility?
Both sperm count and sperm morphology are important for conception, but sperm morphology may matter a little more than the count. Less than 40% of the sperm ejaculated is sufficient to move up the fallopian tube to fertilise the egg. However, if this 40% is not healthy in terms of formation or shape, it cannot fertilise the egg.
Some factors that affect or impact the sperm count and sperm morphology are:
● Genetic factors – Chromosomal or monogenic disorders can lead to low sperm count or poor sperm morphology.
● Underlying health conditions – Certain health conditions, especially chronic health issues and infections, can negatively impact sperm health.
● Medications – Certain antibiotics, antidepressants, opiates, and other medications can block sperm production, reduce sperm motility, or interfere with the testosterone or sex drive.
● Exposure –Exposure to heat like sauna or hot baths, exposure to chemicals, and wearing tight clothing can negatively impact sperm production and health.
Both sperm count and sperm morphology are analysed in a routine semen evaluation. This is usually done only when a male faces difficulty in impregnating his partner. A man’s body keeps producing fresh sperm every few days. A change in his diet and lifestyle for a minimum of 3 consecutive months can improve his sperm health considerably – this includes both sperm morphology and sperm count.
If a couple decides to undergo IUI or IVF, a sperm wash can help isolate the healthy sperm from the sample. Sperm washing is a process of extracting healthy and motile sperm from the sample. The technician will use the centrifuging or spinning method to separate the healthy sperm from the specimen. These healthy sperm are concentrated into a special HTF solution for nourishment and preservation. When it is time, they will inject this sperm into the vagina or the egg for fertilisation.
If the sperm are not in shape, no matter how many sperm there are, they can’t penetrate the egg for fertilisation. Similarly, even if the sperm are of the perfect shape, if there are not enough sperm per ejaculation, it can delay conception. Both sperm count and morphology are crucial for a successful conception and pregnancy outcome. With a little effort and changes in one’s diet and lifestyle, both sperm count and morphology can be improved.
● When there is not enough sperm per ejaculation, it reduces the chances of the sperm travelling up to the egg and penetrating it for fertilisation. Though only one sperm needs to penetrate the egg, a sperm count of at least 5 million per mL of semen is required for conception.
● Yes, a low sperm count can still result in pregnancy. However, it may take more time or require some fertility treatment like IUI or IVF.
● The only way to know about sperm count and morphology is by taking a semen analysis. This test will do a full analysis of the semen sample and give you all the details about the sperm. If all other fertility tests for both partners have negative results, then the low sperm count or poor sperm morphology could be the reason for fertility issues.
● Habits like regular alcohol consumption, use of tobacco or drugs, being overweight, exposure to radiation or toxins, and wearing very tight underwear and pants can all affect sperm count and morphology.
