There are three main problems causing infertility in Singapore, noted Dr Sheila Loh, consultant obstetrician and gynaecologist at Raffles Hospital.

"Endometriosis, ovulation problems (this could be polycystic ovaries or a hormonal imbalance) and male factors.

"We always talk about women but there are genetic abnormalities in the quality of the sperm too," she said.

In endometriosis, cells that normally grow inside the uterus (womb) instead grow outside the uterus. The cause is unknown.

In polycystic ovary syndrome, women have either irregular or no menstrual periods. It affects 5-10 per cent of women of reproductive age.

According to the World Health Organisation, about 15 per cent of couples seek medical help for fertility issues.

Age is definitely a contributing factor, believes Dr Loh.

She said: "The optimal age of conception is between 22 and 26. Once a woman turns 35, egg numbers and egg quality decline."

This lowers conception chances.

And, again, it's not just about the women.

She said, "Men over 40 years have lower levels of male hormones, which result in poorer quality sperm."

There are ways you can maximise fertility, suggests Dr Loh: eliminate alcohol, avoid smoking, eat a well-balanced diet, keep stress in check and, perhaps the most important point, make time and plenty of it for baby making.

Said Dr Loh: "There is a greater chance of pregnancy just before or after the ovulation stage of the menstrual cycle, but the exact moment varies from month to month."

So setting your alarm for that perfect baby-making moment is not only ineffective, but it will probably just add to the stress of trying to conceive.