A semen analysis report often arrives as a sheet filled with numbers – concentration, motility, morphology – each accompanied by a reference range. For many couples, those numbers either bring relief or quiet alarm. Yet, interpretation is rarely that simple.
Dr Nimisha Shantilal Pandya, Fertility Specialist at Birla Fertility & IVF, Ahmedabad, says male factor infertility contributes to nearly 40–50% of infertility cases globally. Despite this, semen analysis remains one of the most misunderstood tests in fertility care. A ‘normal’ report does not automatically guarantee fertility, just as a mildly ‘abnormal’ value does not confirm infertility.
Understanding the numbers
The World Health Organization’s 2021 laboratory manual updated the lower reference limits for semen parameters based on men whose partners conceived within a year. These include a sperm concentration of 16 million per millilitre, total motility of 42%, progressive motility of 30%, and 4% normal morphology under strict criteria.
These figures are often mistaken for definitive markers of fertility. In reality, they represent statistical lower reference limits – the lower fifth percentile among fertile men. Falling slightly below them does not automatically mean infertility; being above them does not guarantee conception.
The 2021 manual also cautions against rigid interpretation. Semen analysis is a snapshot influenced by factors such as illness, laboratory variation and the period of abstinence, which is ideally 2–7 days. Numbers must be read in context, not in isolation.
Motility and morphology: More than percentages
Rapid progressive motility is particularly relevant. These are the sperm capable of travelling through cervical mucus and reaching the fallopian tube for natural fertilisation. A report showing adequate count, but poor progressive motility often explains delayed conception more than a marginal dip in concentration.
Morphology is often the most misunderstood parameter. It refers to the shape and structure of individual sperm. Under strict criteria, a sperm must meet very precise standards in all these areas to be classified as a ‘normal form’. Because the assessment is so strict, only 4% normal forms are required to fall within the WHO reference range. This does not suggest that the remaining sperm are non-viable or genetically abnormal. It reflects how rigorously laboratories define structural normality.
When ‘normal’ is not the full story
Up to 15–30% of couples are labelled with unexplained infertility. In such cases, even with a seemingly normal semen analysis, further testing such as sperm DNA fragmentation can offer deeper insight. Studies have shown higher DNA fragmentation levels to be associated with reduced pregnancy rates and increased miscarriage risk.
A semen analysis is a starting point, not a verdict. Its value lies not in isolated numbers, but in thoughtful interpretation – aligned with clinical history, female factors, and, when necessary, advanced testing. Only then does the report begin to truly speak.
