Women are at the mercy of their biological clock, with studies pointing to 35 as the average age at which fertility begins to decline. It presents a challenge or crisis for any woman who finds herself longing for a baby in her mid-30s or over.
Yet a woman can take steps to increase her chances of conceiving when she reaches this threshold. She may never have the freedom of men who can father children later in life -- think Rod Stewart who recently had his eighth child at age 66, yet celebrity mums like Victoria Beckham, who is expecting her fourth child at age 36, and Dannii Minogue who gave birth to her first baby at 38, are a source of inspiration.
Other well-known mums who have broken through the 35 age barrier are Jennifer Lopez, who had her twins at age 38, and Muriel's Wedding actress Toni Collette who is expecting her second child at age 38. Here are 10 steps a woman in her mid-30s or over can take to boost her fertility.
1 Quit smoking: Smoking has been linked with infertility. It can bring on an early menopause, which is a particularly important consideration for older women who may be trying to beat the clock.
2 Cut back on caffeine: There is plenty of evidence to show that caffeine decreases fertility. Drinking one cup of coffee a day can halve your chances of conceiving. One study showed that problems with sperm increase with the number of cups of coffee consumed each day.
3 Stay sober: Drinking alcohol can reduce your fertility by half -- and the more you drink, the less likely you are to conceive. One study showed that women who drink less than five units of alcohol a week (five glasses of wine) are twice as likely to get pregnant compared with those who drink more.
4 Relax: High levels of the stress hormone cortisol can stop ovulation and render women temporarily infertile, researchers have shown. They found that cognitive behavioural therapy -- which promotes positive thinking -- helped women's periods return and their fertility to return to healthy levels.
5 Balance your hormones: Xenoestrogens are essentially environmental oestrogens, coming from pesticides and the plastic industry. When you are trying to conceive, one of the most important things you need to do is to balance your hormones. It is important to avoid anything that might cause an imbalance, and one of the main culprits is the xenoestrogens. One of the best ways to eliminate an excess intake of xenoestrogens is to buy organic produce.
6 Drop weight: Studies show that being overweight can hinder a woman's chances of conceiving. If you are overweight, it can be helpful to lose at least 10pc of your current weight.
7 Eat cheese: Women who drink whole milk and enjoy eating cheese have a better chance of becoming pregnant than those who stick to skimmed milk and low-fat dairy products.
8 Manage endometriosis: As many as one in 10 women has some degree of endometriosis, a condition where cells similar to those which line the uterus grow in other parts of the abdomen -- causing heavy periods, back pain and discomfort during sex.
9 Consider acupuncture: There are studies done in women with fertility treatments which show that acupuncture can improve fertility. Some evidence suggests that acupuncture reduces stress, which can be a major cause of infertility.
10 Freeze your eggs: Medical advances now allow doctors to freeze eggs until women are in a position to start a family. This technique was developed for women undergoing cancer treatment, and has now resulted in the births of 300 babies worldwide.