Sperm under the microscope: what count, motility and morphology mean
Under a microscope at 400x magnification, healthy sperm look like tiny tadpoles, each with an oval head and a long, beating tail. A semen report describes three main things: count (how many sperm there are), motility (how well they swim) and morphology (how normally they are shaped). Dr Mayur Pai explains what each one means.
Watch on YouTube if the player does not load.
In this short video, Dr Mayur Pai shows a sperm sample taken for IUI under the microscope, magnified four hundred times. This page explains what you are looking at, and how it connects to the lines on a semen report.
What does a sperm look like at 400x?
A single sperm is far too small to see with the naked eye. At 400x it becomes a small, bright shape with three parts:
- The head is an oval that carries the father's half of the genetic material. A cap on its tip helps it get through the outer layer of the egg.
- The midpiece is a short neck packed with the energy the sperm needs to swim.
- The tail is long and whip-like, and it beats to drive the sperm forward.
In a healthy sample, many sperm cross the screen and a good number of them swim briskly forward. You will also see some twitching in one place, some lying still, and a few other cells and specks of debris. No sample is made up only of perfect sperm, and none needs to be.
Count: how many sperm are there?
The count is reported in two ways. The concentration is how many sperm there are in each millilitre of semen. The total count is how many there are in the whole sample. Both matter, because a small volume can make a good concentration look better than the total really is.
Your report prints a reference range beside each result. A count below that range is called oligozoospermia. When no sperm are seen at all, it is called azoospermia, and that needs its own set of tests. A count below the range does not mean pregnancy is impossible, and a count within it does not promise one.
Motility: how well do they swim?
Motility describes how many sperm are moving, and how. Laboratories usually sort them into three groups:
- Progressive: swimming forward, in a fairly straight line or in wide circles. These are the sperm that can travel up to the egg.
- Non-progressive: moving their tails but getting nowhere, twitching on the spot or spinning in tight circles.
- Immotile: not moving at all.
Progressive motility is usually the figure that matters most, because only a forward swimmer can make the journey. Low motility is called asthenozoospermia. Sperm that are not moving are not always dead, and a separate vitality test can tell the difference when it matters. Motility also drops if a sample gets cold or waits too long before it is examined, which is why laboratories examine it soon after it is produced, kept warm.
Morphology: how are they shaped?
Morphology looks at the shape of each sperm, usually on a stained slide at a higher magnification than in the video. A normal sperm has a smooth oval head, a neat midpiece and a single, uncoiled tail. Abnormal forms include heads that are too large, too small, tapered or doubled, and tails that are bent, coiled or doubled.
This is the result that worries couples most, and it usually does not need to. The standard for a "normal" sperm is very strict, and even men who have fathered children easily have only a small share of sperm that meet it, so the normal-forms figure nearly always looks low. Poor morphology is called teratozoospermia, and it matters most when it comes together with a low count and poor motility.
What do the other lines on the report mean?
- Volume: how much semen was produced. A very small volume may mean part of the sample was missed, or occasionally points to a problem worth checking.
- Liquefaction and viscosity: semen is thick at first and should turn liquid within a short while. If it stays thick, it can hold the sperm back.
- pH: how acidic or alkaline the fluid is, which can hint at a blockage or an infection.
- Pus cells: white blood cells. A raised number can suggest an infection, which can be treated before fertility treatment starts.
- Agglutination: sperm stuck together in clumps, which stops them swimming freely.
How should you read your own report?
One report is a snapshot, not a verdict. Counts rise and fall naturally. Sperm take about two to three months to form, so a fever or illness in the past few months can pull a result down for a while. If a report is low, we usually repeat it before drawing any conclusion.
Prepare for the test properly. Leave a gap of two to five days without ejaculation, collect the whole sample into the sterile container the laboratory gives you, and do not use any lubricant, because most lubricants harm sperm.
Read the numbers together. What matters for treatment is how many healthy, forward-moving sperm there are in all. That depends on count, motility and shape together, and it is always read alongside the wife's own tests.
What happens after the semen analysis?
If the report is normal, attention turns to the wife's side, although the couple is always assessed together. If the count or movement is mildly reduced, IUI with washed sperm is often a sensible first step: the laboratory separates and concentrates the most active sperm, as explained in sperm preparation for IUI. How these situations are planned is covered in IUI for a low sperm count and IUI for poor sperm motility and morphology. When the sperm are very few or very weak, IVF with ICSI, where a single sperm is placed directly into each egg, is usually the better route.
Many causes of a poor report can be found and improved. Male infertility explained covers the common causes and what helps.
Where treatment happens
This guide is by Dr Mayur Pai, MBBS, MS (Obstetrics & Gynaecology), a fertility and laparoscopy specialist. Pai Hospital in Goa has its own operating theatre and its own IVF laboratory, so the semen analysis, the sperm preparation and any treatment happen in one place, under one team. Free patient transport is available: the hospital's car collects you from anywhere in Goa and takes you home again.
Getting started
For questions, send a photo of your semen report with a short message on WhatsApp to +91 95185 02773. To book a consultation, call our reception on +91 95459 20817; consultations are by appointment and are held in Panjim, Margao, Mapusa and Vasco. Treatment packages are transparent and fixed, so ask us for the details. This article is for education only and is not personal medical advice; please consult your doctor about your own situation.
Your questions
What do healthy sperm look like under a microscope?
At 400x magnification, healthy sperm look like tiny tadpoles, with an oval head, a short midpiece and a long tail that beats to push them forward. In a good sample many of them swim briskly across the screen, alongside some that twitch in place or lie still. That mix is normal.
What is the difference between sperm count and motility?
Count is how many sperm there are, either in each millilitre or in the whole sample. Motility is how well they swim, and forward movement matters most, because only a forward swimmer can reach the egg. A plentiful count of sperm that barely move can be less useful than fewer strong swimmers.
My morphology result is very low. Is that serious?
Not necessarily. The standard for a normally shaped sperm is very strict, so even fertile men have only a small share of perfectly shaped sperm. Poor morphology matters more when the count and motility are also low, and the doctor reads all three together.
What do pus cells in a semen report mean?
Pus cells are white blood cells. A raised number can point to an infection, which can usually be treated with a course of medicine before fertility treatment begins. The test is then often repeated to check that it has settled.
Should I repeat my semen test if the result is low?
Usually, yes. Counts vary from one test to the next, and a recent fever or illness can lower them for a while. A second test after a gap, with two to five days of abstinence beforehand, gives a much more reliable picture.
Or call +91 95185 02773
This page is for general education and is not personal medical advice. Treatment depends on your own examination and reports, so please speak to a doctor about your situation. We do not carry out or offer sex determination of any kind.