Doctors on Saturday said consumption of tobacco products such as smoking causes infertility in both males and females.
Fertility experts have said tobacco and other types of narcotics can also cause occurrence of early menopause in women.
According to the World Health Organisation (WHO), till 2015, India had 12 per cent of the world's tobacco users with over 108 million smokers.
"One should avoid using tobacco (cigarettes) and marijuana. They reduce fertility, especially by reducing sperm counts. Smoking damages sperm, making them less likely to fertilize eggs. The embryos they create are less likely to survive," said Arvind Vaid, an In Vitro Fertilization (IVF) Specialist at Delhi-based Indira IVF Hospital.
Studies have also revealed that compared to non-smokers, active smokers were 14 per cent more likely to be infertile and 26 per cent more likely to have early menopause.
Noting that while cigarettes do not necessarily cause infertility, Vaid said they can have an adverse effect on a couple's ability to conceive.
"The problem exists in men as much as in females," said Vaid.
Parbeen Mehta, a gynaecologist at Ram Manohar Lohia Hospital, said human sperm cells carry two tiny, highly charged proteins called protamine 1 and protamine 2 which are in a perfectly balanced one-to-one relationship.
"However, sperms of the smokers carry very little protamine, which makes them highly vulnerable to DNA damage," said Mehta.
She said passive smoking may also affect male fertility.
"Male smokers can suffer decreased sperm quality with lower mobility and it boots numbers of abnormally shaped sperms. Also, if one is a chain smoker then it might also decrease the sperm's ability to fertilise eggs," said Mehta.
According to Parth Joshi, another IVF expert, women who smoke tobacco, marijuana and several other narcotic products may have early menopause.
"Gradually, by the time a woman enters her 30s, her fertility starts declining which speeds up after she is 35 years and beyond. Tobacco can cause it early," said Joshi.