News, Culture & Society

Men may be able to smell how fertile a woman is, scientists discover

Can men smell how FERTILE women are? Males are more attracted to the body odours of females who produce high amounts of oestrogen, claims study

  • Group of men ranked the body odours of 28 women of a reproductive age
  • Found smells more pleasant if produced by a woman with high oestrogen
  • Oestrogen causes eggs to mature in a girl’s ovaries when she reaches puberty

Men may be able to smell how fertile a woman is, research suggests.

Scientists from the University of Zurich asked a group of males to rank the body odours of 28 women of a reproductive age. 

The women had previously been tested for their levels of key fertility hormones.

All the men agreed the most pleasant odours were given off by women with the highest levels of oestrogen.

Oestrogen regulates the menstrual cycle and causes eggs to mature in a girl’s ovaries when she reaches puberty.

Since this hormone is a ‘signifier of fertility’, the findings suggest ‘body odours are linked with reproductive health, which men can sense via smell’, the researchers said.

Men may be able to smell how fertile a woman is, research suggests (stock)

Infertility affects around one in six women in the UK, statistics show.

And in the US, one in 10 struggle to get or stay pregnant, according to the Center for Disease Control and Prevention. 

Infertility in women is usually caused by problems with ovulation, such as an egg not being released, the NHS states.

In men, poor-quality semen, the fluid that contains sperm, is often to blame.

What is infertility?

Infertility is when a couple cannot get pregnant despite having regular unprotected sex. 

It affects one in seven couples in the UK – around 3.5 million people.

About 84 per cent of couples will conceive within a year if they have unprotected sex every two or three days.

Some will conceive quicker, and others later – people should visit their GP if they are concerned about their fertility.

Some treatments for infertility include medical treatment, surgery, or assisted conception, including IVF. 

Infertility can affect men and women, and risk factors include age, obesity, smoking, alcohol, some sexually transmitted infections, and stress.

Fertility in both genders decreases with age – most rapidly in their 30s.

Source: NHS 

However, for around a quarter of couples who are struggling to conceive, there is no clear cause. 

Past studies have shown the smells produced by a woman’s hormones can make her more attractive to the opposite sex. 

However, whether this is an indicator of her fertility was unclear. 

To find out more, the researchers asked men to rate the body odours of 28 healthy women.

The women had previously been tested for their levels of the hormones estradiol, progesterone, testosterone and cortisol.

Estradiol is one of four ‘dominant’ oestrogen hormones that occur naturally in women.  

Progesterone maintains the lining of the uterus in preparation for the attachment of a fertilised egg. 

If ovulation does not occur, progesterone levels fall and a woman sheds the lining during her period.

Although testosterone is higher in men, it also gives women their sex drive.

Finally, cortisol, ‘the stress hormone’, was looked at. Feeling frazzled is known to affect a woman’s chances of conceiving.  

Results revealed all the men found the odours of women with high levels of estradiol in their saliva the most attractive. 

Perhaps surprisingly, the males were also drawn to the females who produced low amounts of progesterone, despite its links to fertility.

The full results will be presented at the 50 Years of Psychoneuroendocrinology conference in Milan on Saturday. 

‘Since estradiol and progesterone levels are signifiers of reproductive health and fertility, researchers suggest body odors are linked with women’s reproductive health, which men can sense via smell,’ the authors wrote.