It's estimated that around 40% of pregnancies today are unplanned; that means almost half of all pregnant women conceive without even trying. And yet, at the same time, 15% of women struggle to get pregnant and a further 10% are diagnosed with infertility. It hardly seems fair, does it?

If you're trying for a baby but are having difficulty conceiving, each passing month can bring further disappointment and lack of hope. Time seems to stand still, and, even if you've only been trying for a couple of months, it can feel like a lifetime. Fortunately, 85% of couples will, with regular trying, conceive naturally within one year, but how do you know when it's time to stop playing the waiting game and start to take action?

Couples Under 35

In healthy couples under the age of 35, 20% will manage to conceive within the first month of trying. Although this may seem great, it can comes as quite a shock to many couples who had planned on things taking a little longer! 95% of couples under 35 will successfully conceive within two years of trying, and it's generally at this two year mark that younger couples are examined in detail. A diagnosis of unexplained infertility is unlikely to be made before this point.

Two years seems like forever, right? Fortunately, many Doctors will begin to take your fertility struggles seriously after one year, although it may simply be a case of being in the system rather than being referred for tests. Women who have previously been on the contraceptive pill may be advised to keep trying for a while longer as it can take upwards of one year for the menstrual cycle to sort itself out and return to normal.

If couples are overweight, heavy smokers or drinkers or are suffering with stress, some small lifestyle changes may be suggested and it will probably be advised that these couples continue trying to conceive for a while longer to see if these changes can make any difference.

It is suggested that couples have unprotected sex at least two or three times per week, and even more frequently during ovulation which is when women are most likely to get pregnant, so you'll need to keep your energy levels up!

Couples Over 35

Couples have chosen to delay parenthood further and further over the past few years, as the average of mothers has risen from 26.4 in the 1970s to 29.5 today. Unfortunately, our body clocks haven't yet figured this out, and are still working to the thousands of years old notion that we're having babies in our teens (and indeed, some of us are). After all, menstruation, which is all about pregnancy, usually begins around age 13.

As our body clocks are still years behind the times, fertility levels peak around the late teens or early 20s. That's right, even young 20-somethings are technically past their best when it comes to fertility (feel old yet? I do!). So fertility rates are constantly dropping the older we get, but they take a bit of a larger decline after age 35.

After age 35, the chance of naturally conceiving within one year drops from 85% to 60%, and from 95% to 85% after two years of trying. Women are advised to see their Doctor after one year of being unsuccessful which is when tests will usually begin. In many circumstances, couples will be referred for testing sooner rather than later as fertility rates will just continue to drop. Women aged over 38 are advised to see a Doctor even sooner; after around six months if not earlier.

Once again, it's suggested that couples have unprotected sex two to three times per week, and more frequently during ovulation. No one said trying for a baby was going to be easy work!

Existing Medical Conditions

Men and women with existing medical conditions that could cause problems conceiving should see a Doctor straight away, as the problem may be easily treatable or alternative methods of conception could be looked into. If you're pretty sure you won't be able to conceive, don't waste your time, get yourself checked out.

For women, anything that could cause a blockage in the fallopian tubes should be looked at. For example, if you've ever tested positive for sexually transmitted diseases, have had a previous ectopic pregnancy or abdominal surgery (including an appendectomy) it's worth seeing your Doctor. The same is true if you've been diagnosed with pelvic inflammatory disease, endometriosis, or hormonal imbalances including polycystic ovary syndrome.

For men, get checked out if you've had any positive tests for sexually transmitted diseases, or any surgery to the penis or testicles. If you suffer with premature ejaculation that's another infertility risk factor, or if you've been diagnosed with any hormonal imbalances.

Of course, it goes without saying that if you've had a previous diagnosis of infertility, there's really very little chance of conceiving naturally (although it can and does happen, so that doesn't mean you shouldn't keep having sex!) and you should see a Doctor immediately if you've decided to have a baby. Your Doctor will be able to talk through your options and get things moving in the right direction.