Hello everyone,
Today, we have another episode of our fertility series. We bring in a very key component in conception: your partner. If you’re on a fertility journey with PCOS, chances are most of the focus has been on you - your hormones, your ovulation, your diet, your supplements. And yes, a lot is going on when it comes to managing PCOS. But fertility is a 50/50 partnership, and sometimes we forget to ask the important question: How’s the partner doing?
In this episode, we answer important questions:
How does sperm production work?
Do men have a biological clock?
What tests should we do to assess men’s fertility?
What is important when it comes to sperm for optimal fertility?
What are the top things that affect sperm quality?
What are the top things men should pay attention to to give their sperm the best shot?
Is there anything special that male sperm needs to do for PCOS?
As a reminder, this is a five-part series to deep dive into our ability to conceive with my colleague Daria, a Nutritional Therapist who specialises in fertility.
PS: the articles are both in video and written format to fit both preferences of consuming information.
Exclusive for members: This in-depth article is part of our premium content. Subscribers enjoy comprehensive PCOS deep-dives, customised meal plans, expert medical insights, and direct access to ask me questions. Invest just £1.74/week in understanding and managing your PCOS effectively.
How does sperm production work?
Male sperm takes about 75 days to mature. The process starts in the seminiferous tubules in the testicles under the influence of FSH (follicle-stimulating hormone) where the sperm is produced. Production involves various stages (spermatogonial, spermatocyte and spermatid) and takes around 64 days. At the end of it, sperm cells have a tail and hopefully the correct number of chromosomes. After 64 days, those sperm cells travel into the epididymis, which is a highly-coiled tube attached to the testicles, where they spend a further 10-14 days gaining motility and the ability to fertilise an egg.
Do men have a biological clock, too?
Yes absolutely age does affect male fertility. Although the effects are not as pronounced as for women and there is anecdotal evidence for men who father children in their 90’s that is actually really quite rare. A large 2015 study analysed over 10,000 samples using DNA and found the oldest father to be 65,4 years old. There is however a woman who conceived naturally and gave birth to a son at the age of 59 if we were to look for outliers.
When we look at more of an average population picture some research suggests that male fertility starts to decline from 30. The reality is that the older the man, the higher the chances for them to have suboptimal semen parameters, higher levels of DNA damage, poorer fertility outcomes and offspring health. A 2022 systematic review looking at fertility in ageing males, whilst recognising somewhat conflicting results of paternal age impact on fertility, found age negatively affecting nearly all semen analysis parameters, DNA fragmentation, risk of miscarriage and offspring genetic disorders in a lot of analysed studies. Another research looked at the time it took women to get pregnant and found that in couples where male partners were over 45 it took them 5 times longer to conceive when compared with younger males.
Part of the reason the sperm quality is not given as much attention as it perhaps should is that a lot of male infertility factors could be overcome with ART (Assisted Reproductive Technologies) such as IVF (In-Vitro Fertilisation) and ICSI (Intracytoplasmic Sperm Injection). ICSI is a fertilisation technique used in IVF where a single sperm is injected directly into an egg.
How do we diagnose an issue with man fertility?
The good news about checking man fertility is that it is much easier to check the end product - the sperm itself which is regularly produced and easily connected, whilst it is almost impossible to assess the quality of the female egg directly. The main two tests to check male fertility are:
Semen analysis - this involves a sample of your partner’s semen being tested to check the amount of sperm in it. The test also checks how well the sperm moves, a parameter called motility and the shape of the sperm which is called morphology.
Semen DNA fragmentation - The human sperm cell, in fact, is not just responsible for the expression of the father’s genes but also for activation and the development of the embryo during and after implantation. This test checks for the occurrence of breaks in the long DNA chain, a.k.a. the presence of separated fragments of DNA.
The above two tests are a good place to start. Conventionally the semen analysis would be done after 1 year of unprotected intercourse, and after 6 months when partners are 36 or over. If sperm parameters are abnormal other tests would be done to try and understand the root cause. This could include looking at man’s overall state of health including hormone levels such as LH and testosterone, blood sugar regulation and nutrients status amongst others.
If there are established fertility issues it would be worth checking for infections and looking into seminal microbiome. Some infections such as Ureaplasma and Mycoplasma are often not causing any symptoms in men whilst potentially significantly reducing fertility. Some infections would decrease semen parameters whilst others might negatively affect female microbiome, decrease implantation chances and increase risks of miscarriage.
What is important when it comes to sperm for optimal fertility?
All the parameters that are measured in the semen analysis which is mentioned above are important. First let’s discuss what semen is because not all of the ejaculate or semen (what is expelled by the male partner during orgasm) is sperm cells. Semen is 60% alkaline seminal fluid containing nutrients, 30% thin milky fluid which again contains nutrients for energy production and also some molecules to increase sperm fluidity and only 10% sperm.
Semen is analysed as a whole and various parameters are measured. Sperm count and concentration measures the number of sperm cells in a sample. It is of course important to have enough sperm cells in the ejaculate. Motility describes sperm ability to move or swim normally and progressive motility refers to the ability to swim in a straight line. It is one of the most important factors in male fertility as sperm cells need to have an ability to swim upstream in the female reproductive tract and also penetrate the egg. Morphology describes the size and shape of sperm when evaluated under the microscope. Most sperm cells are abnormal morphologically with current cut-off set at 4% meaning if a sample has 4% and over of sperm cells which have normal shape (and 96% are abnormal) the sample is regarded “normal” for this parameter. Other parameters would be tested as well such as semen volume and pH amongst others.
Another really important parameter is how intact the DNA is inside the cell. In general if any of the semen parameters are suboptimal it correlated with higher DNA fragmentation. However, sometimes a man can have totally “normal” semen analysis as judged by the current criteria but an elevated DNA fragmentation score which is strongly correlated with poor fertility outcomes.
What are the top things that affect sperm quality?
(top 3) - maybe we can mention temperature, tight underwear (it seems a thing on the internet, not sure it’s a thing scientifically)
There are so many! Age as we mentioned before, temperature of sperm production, dietary habits including consumption of refined carbohydrates and fat quantity and quality, lifestyle habits such as drinking alcohol and smoking, toxicity, medications, infections, general state of health and so much more. Which factors play the biggest role for each individual will vary based on their medical history, diet and lifestyle. Let’s start with the the temperature
Sperm production works best at a temperature lower than the core temperature. Specifically, the optimal range for spermatogenesis is 34°C to 35°C, which is approximately 2–4°C lower than the normal human body temperature of 37°C. That’s why testes, which is the main site of spermatogenesis, are located outside of the body. This cooler environment is crucial for the development of healthy and motile sperm, as higher temperatures can impair sperm count, motility, and DNA integrity. One study compared semen parameters in healthy men who agreed to subject themselves to scrotal heating for 30-40 mins 2 days per week for 3 months. Sperm parameters such as sperm count, motility and morphology were decreased and DNA damage increased as a result of overheating.
Certain medical conditions lead to overheating and are known to reduce fertility in men including undescended testes (when testes stay inside the body) or varicocele (varicose veins on testes which lead to increased blood flow and elevated temperature). A number of lifestyle factors contribute toward testicular heat including being sedentary for a long time, using a laptop on the lap, regular use of hot bath and sauna and tight clothing amongst others. Overexercising and cycling in particular could reduce semen quality and negatively affect fertility.
Let’s talk about underwear. Tight underwear which brings testes closer to the body can indeed affect sperm quality. A 2012 study looked at the impact of wearing extremely tight underwear for 120 consecutive days in healthy fertile volunteers. They found that motility and viability of spermatozoa decreased whilst DNA damage increased as early as 20 days into the study. Another study of 656 males found that those who self-reported wearing boxers had a 25% higher sperm concentration and 17% higher total count.
Does frequency of sex decrease the quality of the sperm?
When thinking about frequency of sex people tend to divide into 2 camps - more abstinence or more frequency. Research shows that although abstinence could indeed help with parapets like semen concentration it tends to negatively affect other parameters such as motility and especially DNA fragmentation. And it seems that quality is more important than quality.
Having too frequent intrrcouse can negatively affect sperm quality as well. Research showed that having multiple intercourse in a day decreased sperm parameters. Having intercourse everyday or every other day in the fertility window seems to be an optimal frequency for most couples.
What are the top 3 things man should be paying attention to give their sperm the best shot?
The 4 Fertility Pillars: Nutrition, Lifestyle, Toxins and Supplements are still the same for men as they are for women. Generally a good idea for a man would be to adopt a fertility lifestyle for at least 3 month before conception to increase the quality of the sperm for when the couple actively start trying for a baby.
In terms of diet Mediterranean style of eating still holds strong in terms of impact on both natural and assisted fertility for man. One important point about male diet in particular is paying attention to the amount of antioxidants in the diet. This is linked with sperm quality stronger than with the egg quality in women. Antioxidants are found in fresh vegetables and fruits, particularly brightly coloured ones.
Toxins avoidance is equally if not more important for male partners. It includes avoiding plastics with BPA, phthalates and other chemicals. One thing worth noting is the pesticides. Sperm seems to be quite vulnerable to the pesticides exposure of a man with multiple studies demonstrating diminished semen quality. Looking to choose more low pesticide fruits and vegetables using Clean 15 list and shifting to organic produce whenever possible is a good place to start. Washing conventional produce with water mixed with baking soda also significantly reduces pesticides.
The main lifestyle recommendation is keep it cool! We discussed the importance of lower temperature for sperm production so it should be clear why it’s so important. Opting for loose fitting underwear, avoiding usage of sauna and hot bath, moderating the amount of exercise and particularly cycling and even using cooling underwear is a good way to start.
Is there anything special that male sperm needs to do for PCOS?
This is a great question - and the short answer is no. Sperm doesn’t need to do anything differently in the presence of PCOS, but because fertilisation and early embryo development can be more vulnerable due to inflammation and oxidative stress in the PCOS environment, high-quality sperm becomes even more important.
Interestingly, one study done in 2024 found that about 20% of male partners to women with PCOS had abnormal semen analysis results. This number was higher when compared with a control group where female partners had problems with their tubes as opposed to PCOS. This just highlights that there could be a chance that the partner's sperm could be an issue as well in couples where all the efforts are concentrated around managing PCOS symptoms in a woman.
Another point to highlight is that sperm health becomes even more important when a female partner is slightly older. Most sperm cells have some DNA damage because they are very vulnerable to damage. Female oocyte has an amazing ability to repair some of the sperm DNA damage and this process happens shortly after fertilisation. This process, however, declines as woom ages and as egg quality deteriorates so does its DNA repair ability. It is difficult to say exactly when it happens but the egg's ability to repair DNA reduces after the age of 30 and very significantly after 35. If you could do it early - do it as soon as you could. As it takes around 75 days to produce sperm if there are any issues it would take another 3 months to get sperm quality optimised.
I hope you find this episode useful for yourself, and for your partner.
See you next Sunday,
Francesca.
