A six-week yoga regimen, including physical postures, breathing exercises and meditation, enhanced key biological attributes of sperm in male partners of couples who had experienced recurrent pregnancy loss or repeated embryonic implantation failure, researchers have reported.

The researchers at All India Institute of Medical Sciences (AIIMS), New Delhi, who evaluated the impact of yoga on 60 volunteers said their findings add fresh evidence for the inclusion of yoga as “adjunct therapy” to lower the risk of early pregnancy failure.

Their study has documented significant increases in sperm concentration and motility and favourable changes in a specific set of genes known to influence fertilisation, implantation and pregnancy success.

“Our study analysed the expression (activity levels) of 14 genes after adoption of yoga,” the researchers said, reporting their findings earlier this week in the international journal Scientific Reports.

“The relative expression of the genes assessed post-yoga was found to normalise towards the levels in fertile controls (healthy males recruited as controls in the study),” they wrote.

Paternal factors, specifically key biological characteristics of spermatozoa, play a role in various stages of embryo development — fertilisation onwards. Multiple earlier studies have suggested that cumulative damage to sperm cells resulting from so-called oxidative stress and DNA damage can contribute to fertilisation failure or implantation failure, leading to early pregnancy loss.

The AIIMS team invited 30 male partners of couples that had experienced recurrent pregnancy loss and 30 male partners of couples that had experienced embryonic implantation failure to adopt the yoga regimen. The study was led by Rima Dada, a professor of anatomy who has pursued research on reproductive disorders and recurrent spontaneous abortions among other topics.

The regimen included physical postures that increased pelvic blood flow, breathing exercises, and meditation, prescribed for about two hours per day over a six-week period, the first two weeks at the AIIMS laboratory for molecular reproduction and genetics under the supervision of trained instructors.

At the end of six weeks, the researchers also observed a significant increase in the length of sperm telomeres — or structures made from DNA and proteins that are found at the ends of chromosomes.

Telomeres cap and protect the ends of chromosomes similar to the caps at the ends of shoelaces. Earlier studies have suggested that shorter telomeres in sperm cells are associated with altered semen parameters and male infertility. Some scientists had even proposed in the past that telomere length could be viewed as a new molecular marker for sperm quality and male fertility potential.

In line with those earlier studies, the 60 males in the AIIMS yoga study had on average significantly lower sperm telomere lengths at the start of the study. However, after six weeks of the yoga regimen, there was a significant increase in the telomere length from earlier levels.

The researchers have underlined that multiple studies over the years have suggested that yoga and meditation have positive physical, psychological and health benefits. The AIIMS team also highlighted the potential for yoga and meditation practices to address anxiety, psychological stress or depression that they say are common among couples with infertility or recurrent pregnancy loss.