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Dr. Sun Answers Your Male Fertility Questions

Jan 31, 21 7 min
Dr. Sun Answers Your Male Fertility Questions - Natalist

Thanks for sending in your questions! Natalist Medical Advisor Dr. Sun answered all your questions about male fertility. Follow us on Instagram to ask your questions!

By Urologist and Male Fertility Expert Dr. Andrew Sun

Infertility affects about one in eight couples, and male factor infertility is responsible for about 50% of those cases. Although pregnancy itself is of course inextricably linked to a woman’s body, for heterosexual couples it takes two to get there, which means that navigating infertility affects both partners. This month, Dr. Sun answered your questions about male fertility.

What is the leading cause of male infertility?

Most commonly, problems producing healthy sperm start in the testes. Of the many things that can affect the healthy function of the testis, varicoceles (dilated testicular veins) are the leading reversible cause of male infertility. 

What is the scoop on male secondary infertility?

Secondary infertility can be an unwelcome surprise for couples and a source of much frustration.  Often, something has changed in the man’s life or health which may be impacting sperm quality. The best place to start is with an updated semen analysis.

When should the male first be tested to determine fertility health? 

The official definition of infertility is failure to achieve pregnancy after one year. However, in couples where the man has known risk factors, or if the couple has reason to suspect sub-fertility, we usually recommend around six months. 

What can men do to help increase their chances of conceiving? Should they be doing anything special to help with fertility? 

We say that “sperm is a window into a man’s overall health.” A man’s testicles are a factory where sperm are constantly being made. In order to produce the best product, you need the best ingredients and happy workers. That means that a healthy lifestyle - no smoking, eating a healthy diet, alcohol in moderation, regular aerobic exercise, and good sleep are all beneficial. Additionally, the ingredients in our Prenatal for him have been shown to improve sperm quality in men.

Tips for maintaining sperm quality/quantity when there are no known issues? 

  1. Eat / Move / Sleep - maintain a healthy lifestyle
  2. Avoid hot tubs and excess heat - they can fry the sperm!
  3. Take vitamins / supplements which have been shown to help semen parameters 

📖 Read our Guide to Male Fertility ⟶

My husband had cancer when he was 12-15. Could this be an issue for us conceiving?

Sorry to hear that and I hope he’s doing OK and cancer-free! Yes, that could be an issue, depending on what kind of cancer and what kind of treatments he had (chemotherapy, radiation, etc). The first step would be to get a semen analysis and see what his current status is.

Can having Type 1 diabetes affect your sperm health? 

Yes - most often, T1DM affects the nerves responsible for semen transport and ejaculation, so these men can have low-volume ejaculate. Diabetes can also cause increased oxidative stress and DNA damage, though this association is less well established. This is a helpful journal article on the topic.

Thoughts on finasteride? My husband takes it, and I’ve read mixed info about it. 

Finasteride is very good at what it is meant to do: help prevent hair loss and shrink the prostate. There are probably tons of guys on it that we never see in the clinic, and are fine. However, there are multiple reports of finasteride causing severe sperm impairment, especially in men with baseline low sperm counts. In the last 12 months, I had three patients on Finasteride who came to me with infertility and terrible sperm numbers. Fortunately, all my patients (and those reported in the literature) had dramatic improvement after stopping the drug. In general, most of us believe that finasteride should be used with caution in men desiring fertility.

Are varicocele surgeries helpful for infertility? How often does it work? 

15-25% of men overall have varicoceles, but that number rises to 35-60% in men with infertility. Varicocele remains the most common fixable cause of male infertility. There is near universal consensus in the field that fixing a clinical varicocele in a man with poor semen parameters is helpful. Looking at averages for all studies, sperm counts improve 10-20 million/mL, motility around 6%, and pregnancy rates increase by a factor of ~2.4x.

Is it impossible to conceive while undergoing TRT? How long does it take sperm count to be affected on TRT? Any tips?

Nothing is impossible, but very unlikely...yes. Most forms of external testosterone will almost completely suppress sperm production within four to six months of starting therapy.  It can take anywhere between six months to two years after stopping TRT to recover sperm, and often a special cocktail of booster medications is needed. Notably, there are ways to safely increase a man’s own testosterone production while also preserving sperm production. This is a very specialized area of urology which should be managed by someone trained in male reproductive medicine. 

Most forms of external testosterone will almost completely suppress sperm production within four to six months of starting therapy.

Can high FSH be caused by varicocele or a separate issue? 

A High FSH is a sign that the sperm-producing functions of the testis are impaired. Varicocele is the most common fixable cause, but any primary testicular problem can cause an elevated FSH level.  

Can a semen analysis be done at a regular doctor or do you need to get a referral from a specialist?

Most primary care physicians will not have a semen analysis laboratory at their disposal. In addition to the lab, you also want someone to interpret the results and assess their significance, in addition to offering advice on how to help. This is where we come in as male reproductive medicine specialists! 

Are the tests you can order online to do in home, reliable for figuring out if there is a problem?

At-home sperm tests are an exciting new technology which can be a useful adjunct in the care of our fertility patients. The most validated one on the market is the Legacy test which offers a good analysis of overall sperm quality. However, these tests do not replace the role of a complete workup by a fertility specialist, which includes a more detailed analysis, hormone testing, physical exam, and counseling, among other things.  

Can anything help sperm morphology? His level was 2.5 when we tested.

Morphology can certainly be improved, depending on the root cause. Things such as varicoceles, hormone imbalances, and certain medications can all cause decreased morphology. Your doctor is right in that compared to concentration and motility, morphology does have the least predictive value for pregnancy success. Nevertheless, it is an important piece of the puzzle, and something that a male reproductive medicine specialist can help optimize! We’re here for you!


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Dr. Andrew Y. Sun is a fellowship-trained urologist and expert in the fields of Male Fertility and Sexual Medicine with a passion for helping men optimize their health and well-being. Dr. Sun earned his MD from Harvard Medical School and completed his urology residency at the Cleveland Clinic. Following residency, he pursued subspecialty training in Male Reproductive Medicine and Surgery at the University of California, Los Angeles. 


Featured Image by Rheyan Genn Dela Cruz

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