It is pretty well-known how important it is to eat well during pregnancy, but what about before you fall pregnant?

With about 50% of pregnancies being unplanned, it is handy to work on developing good habits now, to not only enhance your fertility, but it can even impact your future baby’s risk of allergies and chronic diseases too!


In this blog, I will cover the role of nutrition and the environment on your future bub’s genetics, the importance of maintaining a healthy weight before conceiving and the impact pre-conception nutrition and lifestyle has on your baby’s future health outcomes.

Pre-conception nutrition and lifestyle has the power to not only affect your pregnancy and your baby, but also your grandchildren’s health, it’s a big responsibility but, don’t worry, I’ve got you covered!

What is the Pre-conception Period?

The pre-conception period is the 3 to 12 months prior to conception (i.e. sperm reaching the egg and becoming your baby). Three months before conceiving is a critical time as egg cells are developing and maturing before you ovulate. The development of sperm also impacts the health of the embryo, as a full sperm cycle takes about 64 days, so what your man is eating and drinking in the lead up to conceiving can have an impact.

So yes, what you eat now will affect your egg and sperm production in 3 months’ time and potentially your future baby!

As your requirements for specific nutrients increase when you are pregnant and breastfeeding, you don’t want to be behind the eight ball before you fall pregnant.


I recommend that 6-12 months is ideal to help correct any nutritional deficiencies, as well as to optimise your lifestyle and weight for conception and pregnancy.

It is really important to speak to your GP to organise a blood test to understand your current nutritional status prior to conceiving and consult with your dietitian to help get you on track, particularly if you are ceasing contraceptives before conceiving.

Genetics, The Environment and Your Baby

Epigenetics is the term used to describe how environmental factors can affect the expression of genes in your baby’s body. There is some research to show we now have the potential to modify which diseases can be avoided through gene expression, through switching particular genes on and off, much like a light switch, through a process called methylation.

If the wrong genes are switched on, when they are not meant to, then it can impact the health of your baby – and even your baby’s baby (if you were to conceive a female as all of her eggs will be produced in utero, crazy to think about, I know!).


A study in rats indicated that nutrient-poor diets during the development of the foetus can lead to the switching on of stress pathways that cause a higher chance of obesity in the rats’ babies. (Ruijun et al., 2012).

Men are not off the hook though, one study has shown that a male’s preconception health plays a part in epigenetics (Day et al., 2016). A father’s alcohol consumption can have an effect on your baby’s DNA – remember, sperm carries 50% of your baby’s genetic material. Research (although mostly in animals) has seen a higher frequency of low birth weight in babies who have a father that drinks alcohol (Day et al., 2016). The exact amount which may be implicated is not well understood, it is recommended that you do not exceed about 2 standard drinks per day for men, and aim for at least two alcohol-free days per week.

There is, however, much more research needed in this space to further understand epigenetics in humans, rather than just animals.

Healthy Weight for Conception

Maintaining a healthy weight in the 12 months leading up to conception reduces the likelihood of your child being outside of their healthy weight range later in life. Research has indicated that a woman’s weight at the start of pregnancy can predict her baby’s risk of higher weight as they grow up (Davies et al., 2016).

It is also known that being above a healthy weight before pregnancy can impact your fertility and the health of your eggs. There is a greater risk of developing gestational diabetes if you are outside of your healthy weight range at the start of pregnancy, which in turn increases your baby’s risk of developing diabetes themselves.

But, it is not all bad news, doom and gloom! You can make a difference to your own and your baby’s health.

A pre-conception BMI lowered by 10% was shown to reduce pregnancy-related conditions including pre-eclampsia, gestational diabetes, pre-term delivery, macrosomia (large-for-gestational-age babies), and stillbirth (Stephenson et al., 2018).

It can be a little bit scary to think about, however, the research is increasingly showing us that we need to be prioritising the health of men and women well before conception to avoid these adverse outcomes down the track.

Incorporating colourful fruit and vegetables, high-fibre wholegrains, protein and healthy fats in your everyday meals can ensure a balanced diet and help maintain a healthy weight. Low GI foods are particularly helpful for maintaining blood sugar levels, insulin, and weight which is very important for successful fertility.

Speak to your dietitian for tailored information to establish what a healthy weight is for you, pre-conception is NOT the time to be crash dieting ladies and gents!

Future Health Outcomes for Your Baby

Allergies, Asthma & Eczema Prevention

Allergies in children are on the rise. More than 10% of 1-year old children have a food allergy, 1 in 9 children have asthma and 1 in 5 have eczema.

Allergies stem from changes in the immune system, where these alterations can begin during early pregnancy. Nutrition of mums-to-be can influence immune development and function of their baby. So, what can you do to improve immune development before conception and throughout pregnancy?

Allergy prevention strategies include:

  • Fish oil supplementation
  • Folic acid supplementation (should already be in your prenatal supplement)
  • Sufficient prebiotic fibre intake (think garlic, onions, cashews, peanuts, legumes & beans, asparagus)
  • Probiotics for women with a family history of allergies, asthma, eczema
  • Introduce all major allergens during pregnancy: cow’s milk, eggs, fish, crustaceans, peanuts, tree nuts, wheat, sesame, lupin and soy (except if you are allergic to them yourself, of course!)

Asthma prevention strategies:

  • Vitamin E (through food sources such as extra virgin olive oil and nuts, supplementation has not been shown to be as effective)
  • Adequate antioxidant content. A higher intake of antioxidant-rich foods such as fresh fruit and vegetables, herbs and spices are suggested to reduce the risk of asthma and/or eczema in offspring

Eczema prevention strategies:

  • Ensure an adequate vitamin D status pre-conception and during pregnancy. There has not only been a reported association of low vitamin D status during pregnancy with eczema, asthma and food allergy but also increased risk of gestational diabetes, pre-eclampsia and small-for-gestational age infants (Davies et al., 2016)
  • Regular prebiotic and probiotic intake. We know the gut microbiome in the mother is linked to the gut microbiome of her baby’s and how this can play a role in eczema development. Supplementing with Lactobacillus rhamnosus GG is especially important if you have a family history of eczema.

    Read more about the first 1000 days of life and the role of the gut microbiome here.

Chronic Diseases Prevention

Chronic conditions such as obesity in children can be equally influenced by too low or too high body weights in mothers. Studies suggest that mothers undereating and over-exercising (see why crash dieting is NOT a good idea) or who are without food in the lead up to, and during pregnancy, condition their baby to become really good at holding onto energy. Once the child is born, they tend to consume excessive energy because their hunger/full signals have been altered during very early life (Davies et al., 2016).


This may all seem a bit overwhelming but with good nutrition and expert advice – we can overcome this!

Given the various factors of how we as women can influence our child’s (and possibly grandchild’s) life, ensuring adequate nutrition in these very early stages are vital for your baby’s (and your own) health.

Are you planning to conceive in the next 3-12 months? I work with couples trying to grow their family ensure they are in tip-top shape before conception and to help boost their fertility. Get in touch for an appointment.

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Stay tuned for the next blog post about what nutrients are critical in the pre-conception period, don’t miss it by signing up to the weekly blog update email alerts here and get your FREE ultimate pre-conception nutrition and lifestyle checklist for him and for her, or simply scroll to the bottom of this page and enter your email address.

This blog was co-written by Bianca Trajcevski a final-year Master of Dietetics student from Deakin University. You can find her on Instagram @bianca.traj or connect with her on LinkedIn.

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