Can’t Get Pregnant? 5 Possible Reasons Why

Community // 12WBT Staff

You can try, try and try again, but sometimes pregnancy can be elusive. Here’s some reasons why it’s possible that you can’t get pregnant, and what you can do about it.


While studies show that 85 per cent of couples having regular, unprotected sex get pregnant in the first year of trying, the rest aren’t so lucky. Many end up baffled, wondering where they’ve gone wrong – and worried that the only way they’ll have a baby is via fertility treatments.

Comparing yourselves to other couples who may do all the ‘wrong things’ but have no problem falling pregnant isn’t helpful, explains Dr Simone Campbell from Brisbane’s City Fertility Centre.

“We all know of couples who are overweight and get pregnant easily,” says the fertility specialist. “Or couples who drink a lot or smoke a lot or who are older, and yet get pregnant easily. But I say to my patients, if they were you, you wouldn’t be sitting in my room right now asking for advice.”

But don’t run off to the nearest fertility clinic just yet. Instead, sit down with your partner and answer the five questions on our get-pregnant checklist.

1. Do you… need to lose weight?

If you’ve ever thought being heavier might be impeding your ability to conceive, you’d be right. Studies show the ideal BMI to conceive is between 20 and 25. Getting into a healthy weight range is key – and not just for actual conception, but for pregnancy and the future health of your child.

Calculate your BMI with our BMI Calculator

“When it comes to conception, overweight women can stop having periods,” says Dr Campbell. “Carrying extra weight can also cause irregular ovulation. Plus, if either one of the partners we’re treating is overweight, the chance of conception is significantly reduced. In IVF settings, increased weight in women decreases pregnancy rates. And if the woman is a normal weight but the guy is overweight, their chances are also lower because of the sperm damage that happens with obesity.”

If you do get pregnant when you’re overweight, the risk of complications – miscarriage, diabetes and premature delivery – is significantly higher, she adds, and it’s also worthwhile considering the impact your weight can have on your kids.

“We know there are metabolic changes that happen during pregnancy that predispose the baby to having metabolic syndrome and diabetes when they’re older. It’s so important that, as a society, we all try to get healthier.”

2. Do you… smoke?

This is number one on the list for both men and women, says Dr Campbell. “Smoking obviously affects your general health, but we know it can affect the lining of the uterus, making implantation an issue. Plus, smoking releases a lot of toxins and it’s just not maximising the environment the embryo is going to be trying to implant into.”

Also read: 10 Steps to change a habit

For men, smoking is extra concerning as DNA damage in sperm is often a big factor in infertility and can be overlooked.

“Sperm is created in the testes but stored for three months in the epididymis next to the scrotum,” says Dr Campbell. “And anything you do to your body in that time is going to affect the sperm, including every cigarette you’ve smoked. So, the sperm you ejaculate today has been exposed to every oxidative stress your body’s been under for the past three months.

Damaged sperm is less likely to result in pregnancy and if it does fertilise an egg, it’s less likely to make a nice embryo and more likely to end in miscarriage. We’ve got a good rate here of men stopping smoking, especially when we tell them exactly what smoking does to their sperm.”

Frequent ejaculation is very important as well, she adds. “Two to three times per week just to keep the sperm moving on. Plus, because sperm is stored for three months, any change you make now is not actually going to change your sperm health for 8 to 12 weeks.”


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3. Do you… have sex at the right time?

If you’ve been trying to get pregnant for a while, you’ll know just how tiny that little window of opportunity is each month. Even if you’re having sex two or three times a week, as experts suggest, the chances of egg meeting sperm are surprisingly low.

“You need to learn about yourself and your own cycle,” says Dr Campbell. “Because while you may have read that you need to have sex on day 14, if you actually ovulate on day 19, you may miss that opportunity to conceive.”

How can you know when you’re ovulating? The Billings Ovulation Method teaches you to track changes in your cervical mucus. Or you can use an ovulation kit, which pinpoints the surge in hormones you get 12 to 36 hours before you ovulate. Taking your temperature each morning before you get out of bed is another technique – but it isn’t as helpful, says Dr Campbell.

“The problem with temperature charting is that the big changes happen after you ovulate,” she explains. “So while your temperature chart can tell you that you’ve ovulated, it’s not so good at predicting when you will.”

She adds: “Eggs reliably last for 12 hours, and they can last for 24. Sperm reliably lasts three or four days, although it can last up to five. So if you’ve only got a day when the egg and the sperm are alive at the same time, there’s a good chance you’ll miss that if you’re not onto it. If you’re 25, having sex whenever is fine because when the egg and sperm meet they’re more likely to make a pregnancy. But if you’re 41, you’re fighting the numbers anyhow and you shouldn’t waste any opportunity.”

Also read: Genea’s Top tips for maximising future fertility

4. Do you… have PCOS, insulin resistance or both?

Certain hormonal conditions can hamper your attempts to conceive, such as insulin resistance and polycystic ovarian syndrome (PCOS). The two are often linked. “PCOS can impede your chances of getting pregnant mostly because it might stop you ovulating,” says Dr Campbell.

“Symptoms of PCOS classically include irregular or absent periods, being overweight, having insulin resistance, suffering from pimples or facial hair, and having a classic ‘ring’ of small follicles in the ovary. If you have regular periods, it’s unlikely you have it.”

If you do have PCOS and insulin resistance – and are overweight – studies show that losing as little as 5 per cent of your body weight can help your body start ovulating naturally again. “That’s absolutely proven,” says Dr Campbell. “You don’t have to get back into a normal weight range to necessarily have a chance at pregnancy, and it’s preferable to taking medication which may lead to multiple pregnancies – not a great option for a woman who’s overweight.”

5. Do you… keep putting parenthood off?

Of course, you can’t do anything about your age or when you’re ready for kids – or even when you meet the partner you want to have kids with. But biologically, there’s something to be said for getting your skates on earlier if you can.

In one study published last year in the UK journal Human Reproduction, a whopping 67 per cent of women and 81 per cent of men inaccurately believed that female fertility drops after the age of 40. The reality? A woman’s fertility starts to decline markedly between 35 and 39.

“Your 20s is your best time to try and get pregnant, but by 35 your fertility is dropping,” says Dr Campbell. “And while you may want to wait a few years, you don’t really know what [will happen with] your fertility, so if you want to have babies and you’re in a relationship, get on with it. Women who want to be reassured that they can put it off for the next five years – well, we can’t give them that.”

The problem, adds Dr Campbell, includes our changing society and the fact that many people just don’t meet the right person until they’re older – if at all. “Women don’t choose to be 35 or 39 without a partner and wanting children. It might not be the ideal and what you planned… but in many women, that drive to have kids is pretty strong.”

If you’re single or you’ve been trying for six months and you’re over 35, it can’t hurt to get some advice. “Looking at the statistics, a lot of fertility units have a pregnancy rate of about 40 percent if you’re under 38 and around 30 percent if you’re over 38. And coming to see a fertility specialist doesn’t necessarily mean IVF – it’s about maximising your chances in every way possible.”


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Check out our story about our member Sophie, who fell pregnant after 5 years of trying: Sophie’s 12WBT Story: “12WBT Got Me Pregnant!”