Ladies, some of you will want to release the cougar.

Yes, toyboys can make some women feel younger, they can be more engaged with today’s world than their older male counterparts and they're probably that bit more relaxed, open and fun. There are countless reasons women including celebrities such as Mariah Carey, Kate Beckinsale, Madonna, Heidi Klum and Cheryl Tweedy go for the younger gentleman. But there’s one more we can now add to the list. Researchers from Beth Israel Deaconess Medical Center and Harvard Medical School examined nearly 19,000 cases of IVF treatment cycles between 2000 and 2014. Men and women were grouped into age brackets: under 30’s, 30-35, 35-40, 40-42 and an extra category for men being age 42 and over. They found that women aged 35-40 gained a major benefit in having a male partner below the age of 30 - their chances of successfully having a baby would soar. Although women in their forties did not benefit from having a lover more youthful than themselves (in this sense anyway), young women who were having difficulty conceiving found it much easier to do so, with younger sperm managing to solve the predicament. Having a toyboy gave women a 70 percent relative improvement in cumulative incidence of live birth (chances of a live birth after one or more cycles of IVF) compared to that of 54 percent when they were trying to conceive with a partner their own age. According to Science Daily, lead researcher Dr Laura Dodge said,

“For women age 30-35, having a partner who is older than they are is associated with approximately 11 percent relative decrease in cumulative incidence of live birth - from 70 percent to 64 percent - when compared to having a male partner within their same age band."

It’s not all about our eggs and our age however. A mans age does indeed have a huge role to play when it comes to making babies. Dr Dodge also noted how having children with an older man brings with it risks, such as miscarriage and problems surrounding embryo development. Dr Dodge also said,

“While the effect of female age on fertility is overwhelmingly due to increased rates of chromosomal abnormality, the proposed mechanisms in the effect of male age on pregnancy are more subtle. When we looked at the effect of female age alone, we saw a 46 percent relative decrease from ages under 30 to 40-42, but when we looked at male age alone, we saw a 20 percent relative decrease over the same age span."