Cambridge Urology Partnership

Testicular & Scrotal Conditions & Male Infertility

Low Sperm Count (OAT)

OAT is a combination of low sperm count, poor movement, and abnormal shape. While it's a common cause of fertility struggles, many cases can be improved through lifestyle changes or treatment of a varicocoele, if present.

Key Takeaways

  • OAT is a combination of low sperm count, poor movement, and abnormal shape. While it's a common cause of fertility struggles, many cases can be improved through lifestyle changes or treatment of a varicocoele, if present.
  • We offer specialist diagnostics and treatments. Book a consultation to discuss your options.

Clinical Overview

Understanding Low Sperm Count (OAT)

Oligo-Astheno-Teratozoospermia (OAT) is the most common reason men in the UK struggle with fertility. It is a 'triple finding' where three key areas of your sperm health are below the recommended limits. These are: Oligo (low count), Astheno (poor movement/swimming), and Terato (abnormal shape).

Because your sperm health is a direct reflection of the environment inside your testicles, OAT is often caused by several different factors working together. It can be linked to your genetics, lifestyle choices, or physical issues like a varicocoele (swollen veins in the scrotum). In many cases, a single "smoking gun" cause isn't found, but the good news is that your sperm parameters may be improved with the right support.

What to Look For

Symptoms, Causes & Risk Factors

Recognising early signs and understanding the underlying causes of your condition is the first step toward recovery. This guide outlines common symptoms, when to seek specialist advice, and the factors that may influence your health.

01

Common Symptoms

  • Difficulty conceiving: The primary sign is not achieving a pregnancy after a year of regular, unprotected sex.

  • Low sex drive: A reduced interest in sex or difficulty maintaining an erection.

  • Scrotal changes: Noticing a dull ache, swelling, or a "bag of worms" feeling in your scrotum (a sign of varicocoeles).

  • No outward signs: It is very common for men with OAT to feel perfectly healthy and have no physical symptoms at all until they have a semen analysis.

02

When to Seek Help

  • The 12-month mark: If you have been trying for a baby for a year without success.

  • Abnormal test results: If a home test or private clinic has flagged your semen analysis as "abnormal."

  • If your testis feels abnormal or hard or you have noticed any changes

  • Medical history: If you have ever had a significant injury to your testicles, surgery in the groin, or mumps as an adult.

  • Steroid use: If you currently use, or have used, anabolic steroids for gym or athletic performance.

03

Potential Causes

  • Varicocoeles: Enlarged veins that cause the testicles to overheat, which "cooks" and damages the sperm.

  • Hormone imbalances: Low levels of the signals (LH and FSH) that tell your testicles to make sperm.

  • Lifestyle factors: Smoking, vaping, excessive alcohol, or being significantly overweight.

  • Genetic factors: Small changes in your DNA, such as Y-chromosome microdeletions.

  • Previous testicular surgery: such as an undescended testis or testicular torsion

  • Medical history: a history or diabetes or cystic fibrosis can explain abnormal semen parameters

04

Risk Factors

  • Smoking & Vaping: These are major "sperm killers" that damage the DNA inside each cell.

  • Obesity: Carrying extra weight increases the temperature in your groin and can turn your testosterone into oestrogen.

  • Heat Exposure: Frequently using hot tubs, saunas, or sitting with a hot laptop on your lap for hours.

  • Age: While men make sperm throughout life, the quality and volume naturally begin to dip as you get older

  • Poor Nutrition: A diet lacking in vital antioxidants and vitamins, with too much processed food.

  • Chronic Stress: High levels of cortisol (the stress hormone) can shut down the production of reproductive hormones.

Importance of Diagnosis

Why Early Diagnosis Matters

Finding out you have OAT is actually a positive first step because it helps unlock "reversible" infertility. Once we know the count or quality is low, urologists can look for treatable causes. For example, fixing a varicocoele or making lifestyle changes may restore your natural fertility, meaning you and your partner might avoid the high cost and emotional stress of IVF.

Your sperm health is also a powerful indicator of your overall wellbeing. Medical research has strengthened the link between poor semen quality and a higher risk of future health issues, such as heart disease or diabetes. Treating OAT isn't just about becoming a father; it’s about checking your health as a whole and making sure you are in the best possible shape for the long term.

Importance of Diagnosis

Diagnostic Options & Investigations

To accurately identify the cause of your symptoms, our specialists use a range of targeted investigations. Explore the diagnostic tests below to understand how we confirm a diagnosis and plan your recovery.

Living With Condition

Living With Low Sperm Count (OAT)

  • Varicocoele Embolisation or Microsurgery
  • Hormone Stimulation Therapy (e.g., Clomiphene)
  • Antioxidant Supplementation
  • Lifestyle Modification (Smoking cessation, weight loss)
  • Assisted Reproduction (IUI or IVF/ICSI)

The most important thing to know is the 90-day window. It takes roughly three months for a new batch of sperm to fully mature. This means any positive changes you make today—like quitting smoking or improving your diet—won’t show up on a semen analysis for at least three months. Consistency is your most powerful tool; you have to stick with the changes to see the results.

Specialists

Our specialists for Low Sperm Count (OAT)

Leading experts for this condition. View profiles to see clinical backgrounds and current availability.

Our Commitment

Care you can trust

Every step of your care is delivered to the same standard: senior consultants, a personalised plan, and the safety of an accredited private hospital behind you.

Consultant-Led Excellence

Receive evidence-based care delivered by senior NHS consultants in a professional, specialist setting.

Personalised Care Plans

Your consultant will design a bespoke plan tailored to your condition, health goals and lifestyle.

Hospital-Grade Safety

We operate within leading private hospitals, adhering to strict CQC safety and technology standards.

A Heritage of Trust

Our partners bring decades of NHS and private experience, successfully managing thousands of patient cases.

Patient Guidance

Frequently Asked Questions

Common questions about specialist referrals and consultations.

3 questions

Count (concentration) refers to how many sperm are present in each millilitre of semen. Motility refers to how well they swim. You can have a very high count, but if the sperm are 'slow' or swimming in circles (poor motility), they will never reach the egg. OAT means you have issues with both, plus the shape (morphology).

Reviewed 2 Mar 2026

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Dietary changes may help. Sperm are highly sensitive to 'oxidative stress.' By eating a Mediterranean diet, you may be able to improve motility and morphology within 3 to 6 months.

Reviewed 2 Mar 2026

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Natural conception is still possible with mild to moderate OAT, but it may take longer. If the OAT is severe, urologists often recommend IVF with ICSI (where a single healthy sperm is injected directly into the egg). However, we always try to optimise the male's health first, as better sperm quality may lead to spontaneous conception, and if not lead to higher IVF success rates.

Reviewed 2 Mar 2026

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