Quick guide to getting pregnant: understanding fertility

Updated August 2023 | 4 min read
Expert contributors Dr Wendy Burton, GP (Women's Health, Antenatal Care, Paediatrics); Dr Raphael Kuhn, IVF specialist, author of IVF Success; Professor Clare Collins, Nutrition and Dietetics, University of Newcastle
Words by Karen Burge

Understanding your cycle is essential when trying to have a baby. Here’s how to better understand your fertility and things to consider when getting pregnant.

Making a baby isn’t just about well-timed sex. There are plenty of things going on in your body, and your partner’s, that need to work in sync.

For starters, a healthy sperm needs to travel to and penetrate a healthy egg, which needs to successfully implant in the lining of the uterus.

But even for healthy couples having regular, unprotected sex, it can take months, a year or longer to fall pregnant.

Dr Wendy Burton, a GP who specialises in women’s health, says ideally, couples aren’t time pressured, are having frequent sex without contraception – because it’s fun – and along the way they fall pregnant.

"If there's time pressure, then having sex three to four times a week from the end of the period for a couple of weeks (in an average four-week cycle) covers them very well."

How long does it take to get pregnant?

If you want to give yourself the best chance of conceiving, get familiar with your cycle – specifically, the all-important days when pregnancy is possible. This is known as your fertility window.

A report from The Fertility Society of Australia and New Zealand (FSANZ) suggests that conception is only possible from about five days before ovulation through to the day of ovulation. These six days in total are your fertile window and reflect the lifespan of sperm (five days) and the egg (24 hours).

This same report also shows that the likelihood of conceiving is highest if you have sex in the three days leading up to and including ovulation. If a woman has sex six or more days before she ovulates, the chance she will get pregnant is quite low. Twelve to 24 hours after ovulation, a woman is unlikely to get pregnant during that cycle.

How do you know when you're ovulating?

This will depend on the length of your cycle. If, on average, you have a period every 28 days, you’ll ovulate at around day 14 and your best chances of getting pregnant are between days 11 and 14. You can also monitor your basal temperature to track ovulation. There’s an increase of 0.3 degrees in your basal temperature when you’re ovulating.

Cervical mucus change is a good early indicator that ovulation is approaching, although you can also use an ovulation kit (available from your supermarket or pharmacy) or phone apps that can help track your fertile window using your menstrual cycle data.

What are lifestyle factors that affect fertility?

Along with timing, there are other influences that can improve or hinder your chances of falling pregnant.

Diet and prenatal vitamins

Dr Raphael Kuhn, who is a recently retired IVF specialist and author of IVF Success: An Evidence-Based Guide to Getting Pregnant and Clues to Why You Are Not Pregnant Now (ISO Media, 2017), says diet is an important consideration.

"A Mediterranean-style diet and avoidance of processed or pre-packaged food and high sugar content products – such as soft drinks and fruit juices – is associated with a shorter time to achieve a pregnancy."

Australian research published in the journal Human Reproduction (2018) found that having a diet low in fruit and high in fast food during the pre-conception period were associated with a longer time to fall pregnant. The study involved 5,628 first-time mums and was conducted by the University of Adelaide.

Research conducted by FSANZ suggests that a combination of herbal medicines (Vitex agnus castus and green tea extracts) and nutrients (L-arginine, vitamins E, B6, and B12, folate, iron, magnesium, zinc, and selenium) helped to improve fertility by 26% compared to 10% in the placebo group.

Reduce excess weight

Being in the healthy weight range increases your chances of conception. "If a woman’s weight drops five to 10% prior to pregnancy that can improve her fertility rate. Carrying excess weight means it can take a lot longer to get pregnant," explains University of Newcastle Professor in Nutrition and Dietetics, Clare Collins.

"If dads aim to shape up prior to pregnancy also, it improves erectile function, even within the normal range, and this is important in being able to conceive. Men who are overweight are 20% more likely and men who are obese 30% more likely to be infertile."

What role does age play in fertility?

Fertility declines with age for both men and women. A report by FSANZ suggests female fertility declines after 25. Infertility increases from 1% at age 25 to 55% at age 45. In the same study, male fertility was shown to decline at age 45. While couples can still conceive well into their 50s, there are some risks involved with being an older parent – 20% of women who conceive at 35 can miscarry. Older men are also more likely to pass down inherited or genetic diseases and mental illnesses to their children.

Who should I see for further advice?

If you've been having unprotected sex without any pregnancy luck, then your GP is the best starting point for advice.

"As a rule of thumb, women in their early 30s or younger can wait 12 to 18 months; women in their mid-30s and above should be seen at the six to nine-month mark."

Dr Burton explains that your timing of the visit depends on a few factors. "Couples/women are always welcome to discuss their particular situation with their GP to get tailored advice."

At HCF, we know it can be hard to manage your health in a convenient way. Our partnership with GP2U, an online video GP service, makes it easier for eligible members to access telehealth services. All HCF members with health cover can access a standard GP consultation (up to 10 minutes) for a fee of $50. To register and make an appointment contact GP2U.