Male factor subfertility: what South Asian data shows

Male factor subfertility, abnormal sperm parameters that reduce the likelihood of conception, contributes to approximately 27.3% of infertility cases in India. Asthenozoospermia (reduced sperm motility) is the most common finding, present in 23.4% of Indian men investigated for infertility.

These are not rare findings. In a couple who have been trying to conceive for longer than expected, the male factor is as likely a contributor as any female factor. Testing both partners at the start means the investigation goes in the right direction from the beginning.

Sperm production takes approximately 74 days from start to mature sperm. This means lifestyle, heat exposure, illness, and stress from the preceding three months all show up in today's semen analysis result. A single result is a snapshot, not a fixed verdict.

Sperm production requires a temperature approximately 2–4°C lower than core body temperature, which is why the testes sit outside the body. Sustained exposure to elevated scrotal temperature, from prolonged sitting, laptop heat on the lap, hot baths, or occupational heat in industrial or outdoor work, reduces sperm production and motility.

Occupational exposures studied in Indian male fertility research include heat in manufacturing, chemical exposure in textile and agricultural settings, and sedentary driving or desk work. These are modifiable. Practical changes, avoiding sustained heat exposure, switching to looser underwear, avoiding hot baths in the 74 days before a planned semen analysis, are realistic interventions with evidence behind them.

AZF (azoospermia factor) deletions, genetic deletions on the Y chromosome, are more common in Indian men with severe male factor infertility than in some other populations, based on Indian andrology data. If semen analysis shows severe oligozoospermia or azoospermia, genetic testing is a reasonable next step to discuss with your andrologist.

A semen analysis measures count, motility (movement), and morphology (shape). A single abnormal result does not establish a diagnosis, significant natural variation exists between samples from the same man on different days. Two samples, taken 4–12 weeks apart, give a more reliable picture.

If both samples show abnormalities, the next step is a hormonal profile (FSH, LH, testosterone, prolactin), scrotal ultrasound to check for varicocele, and, if indicated, genetic testing (karyotype, Y-chromosome microdeletion). These investigations guide whether lifestyle intervention, medication, or assisted reproduction with surgical sperm retrieval is the most appropriate route.

Varicocele, dilated veins in the scrotum, is found in approximately 35–40% of men with primary infertility and a higher proportion of those with secondary infertility. It is treatable. If found on ultrasound, surgical repair is the standard approach and is associated with improvement in sperm parameters in a proportion of men.