Fertility Takes Two: Why Sperm Health Matters Before Conception

When a couple has difficulty conceiving or experiences repeated miscarriages, the evaluation often focuses heavily on the woman. Her hormones may be tested, her menstrual cycle monitored, and the health and structure of her uterus evaluated. While these are important pieces of the fertility picture, a healthy pregnancy requires contributions from both partners, and sperm health deserves equal consideration.

A recent article titled "Sperm with DNA Damage Might Be the True Cause of Repeated Miscarriages" brought attention to growing research on sperm DNA fragmentation. This refers to breaks or damage within the genetic material carried by sperm. It is different from what is measured during a traditional semen analysis, which generally evaluates sperm count, movement, shape, and semen volume.

A sperm cell may look normal and still carry damaged DNA. It may even be able to fertilize an egg. However, healthy DNA is needed to provide the instructions that guide the embryo's continued growth and development. Although the egg may be able to repair a certain amount of sperm DNA damage after fertilization, more extensive damage may contribute to poor embryo development or pregnancy loss.

Multiple studies have found an association between elevated sperm DNA fragmentation and recurrent miscarriage. In a 2019 systematic review and meta-analysis, male partners of women with recurrent pregnancy loss had significantly higher levels of sperm DNA fragmentation than men whose partners had not experienced recurrent loss. Another systematic review and meta-analysis reached a similar conclusion, finding an association between sperm DNA fragmentation and otherwise unexplained recurrent pregnancy loss.

This growing body of research has begun to influence clinical guidance. In its updated recommendations, the American Society for Reproductive Medicine states that sperm DNA-fragmentation testing "may be considered" in couples experiencing unexplained recurrent miscarriage or recurrent miscarriage alongside infertility.

That wording is important. DNA-fragmentation testing is not currently recommended as a routine first test for every couple experiencing infertility. The joint American Urological Association and ASRM male-infertility guideline notes that we still need stronger evidence showing that routinely testing for, and treating, DNA fragmentation leads to better pregnancy outcomes. However, it may provide another piece of information when pregnancy losses remain unexplained.

What Can Affect Sperm Health?

Sperm DNA damage does not always have one identifiable cause. Research has associated poorer sperm health with factors such as:

• Cigarette smoking
• Excessive alcohol or recreational drug use
• Certain environmental or occupational exposures
• Obesity and poor metabolic health
• Varicocele
• Genitourinary infection or inflammation
• Recent fever or illness
• Excessive heat exposure
• Increasing paternal age
• Nutrient deficiencies and oxidative stress

A comprehensive review of lifestyle-related causes of male infertility also identified smoking, alcohol use, obesity, psychological stress, dietary patterns, insufficient sleep, and other environmental exposures as potential contributors to impaired semen quality and male reproductive health.

This does not mean that every miscarriage can be prevented through lifestyle changes or that either partner should be blamed for a pregnancy loss. Miscarriage is complex and may involve chromosomal, hormonal, anatomical, immunological, metabolic, or other factors. In many cases, a single cause is never identified.

It does mean that preconception care should include the man rather than treating him as only a source of a semen sample. A thoughtful evaluation may include a review of medications, medical conditions, occupational exposures, smoking and alcohol use, sleep, nutrition, metabolic health, and other potentially modifiable factors.

Because sperm take approximately two and a half to three months to develop, improvements made today may not be reflected immediately. Supporting sperm health is a longer-term process and may involve improving nutrition, exercising regularly, getting adequate sleep, stopping smoking, reducing alcohol intake, managing underlying health conditions, and correcting confirmed nutrient deficiencies. Supplementation should be individualized with the guidance of a qualified healthcare professional.

The takeaway is simple: fertility is not solely a women's health issue. Male health can influence fertilization, embryo development, miscarriage risk, and the overall likelihood of a healthy pregnancy. When couples are preparing to conceive, especially after infertility or recurrent pregnancy loss, supporting and evaluating both partners provides a more complete approach to care.

If you and your partner are preparing for pregnancy, our functional medicine team in Gardner, KS can help you look at the whole picture together. Start that conversation with Root Function Health.

This article is intended for educational purposes and is not a substitute for individualized medical or fertility care.

References:

• Richards SE. Sperm with DNA Damage Might Be the True Cause of Repeated Miscarriages. Scientific American. 2026.
• McQueen DB, Zhang J, Robins JC. Sperm DNA fragmentation and recurrent pregnancy loss: a systematic review and meta-analysis. Fertility and Sterility. 2019;112(1):54-60.e3. doi: 10.1016/j.fertnstert.2019.03.003
• Tan J, Taskin O, Albert A, Bedaiwy MA. Association between sperm DNA fragmentation and idiopathic recurrent pregnancy loss: a systematic review and meta-analysis. Reproductive BioMedicine Online. 2019;38(6):951-960. doi: 10.1016/j.rbmo.2018.12.029
• Practice Committee of the American Society for Reproductive Medicine. Recurrent pregnancy loss: a committee opinion (2026). Fertility and Sterility.
• Schlegel PN, Sigman M, Collura B, et al. Diagnosis and treatment of infertility in men: AUA/ASRM guideline part I. Fertility and Sterility. 2021;115(1):54-61. doi: 10.1016/j.fertnstert.2020.11.015
• Durairajanayagam D. Lifestyle causes of male infertility. Arab Journal of Urology. 2018;16(1):10-20. doi: 10.1016/j.aju.2017.12.004