Secular changes in the semen quality in India during the past 33 years.

Several studies have described a change in semen quality over last 60 years in many regions of the world, but such studies are lacking for the Indian population. In the present study, we aimed at investigating if semen quality has changed during the last 3 decades in normal healthy Indians. We retrieved data on semen quality for Indian men without a history of infertility from published studies and analyzed it for trends in individual semen quality parameters using regression modeling. The semen parameters of 19,734 normal, healthy men from studies published over the past 33 years (from 1978 onward) were used for this purpose. Linear regression analysis weighted by sample size and controlling for age of the subjects revealed a significant decline in sperm motility and a significant increase in sperm concentration. Other semen parameters did not change significantly over this period. In conclusion, there has been a genuine decline in sperm motility and an increase in sperm concentration, which is corroborated by a recent study on Indian subjects.