fertility pregnancy

When Should You Start Taking a Prenatal? A Preconception Guide

If you’re thinking about pregnancy, whether that’s actively trying, “not not trying”, or just keeping the door open, you’ve probably wondered: When should I actually start taking a prenatal?

Is it once you see a positive test?
A few weeks before trying?
Or much earlier than that?

The answer matters more than most people realise, because some of the most important stages of early development happen before many people even know they’re pregnant.

"There is increasing evidence that optimising health in the preconception period is crucial to improving short-term and long-term outcomes for mothers and babies."

Let’s walk through what the guidelines say, why timing matters, and which nutrients are worth paying attention to before conception.

What the Guidelines Say

Australian pregnancy guidelines are very clear on one key point: Some nutrients need to be on board before pregnancy begins.

  • Australian guidance (including RACGP and Pregnancy Care Guidelines) recommends starting folic acid at least one month before conception, and continuing through pregnancy.

  • The World Health Organisation recommends all women should take a folic acid supplement (400 μg folic acid daily) from the moment they begin trying to conceive.

  • Many public health resources, including Healthdirect Australia, suggest ideally starting around three months before trying to conceive.

So why do you see varying timeframes?

Because one month before is considered the minimum effective window, while three months before is increasingly viewed as the optimal one.

From a clinical and nutritional perspective, starting earlier allows time to:

  • Build and stabilise nutrient stores

  • Support egg and sperm development cycles

  • Reduce the risk of missing critical early developmental windows

In practice, many healthcare professionals now advise: If pregnancy is on your radar, that’s usually the right time to start a prenatal.

Why Timing Matters More Than Most People Think

The neural tube forms very early

One of the strongest reasons to start a prenatal before pregnancy is the timing of neural tube development.

The neural tube, which later becomes the baby’s brain and spinal cord, forms and closes between weeks 4 and 6 after conception. That’s often before a missed period or positive pregnancy test.

This is why folate status before conception is so important.
Starting folate once pregnancy is confirmed is still beneficial, but for neural tube development, the most critical window may already be closing.

Nutrients don’t work overnight

Many key nutrients, including iron, iodine, vitamin D and B-vitamins, can take weeks or months to build up in the body, particularly if levels are low to begin with.

Starting earlier helps ensure you don’t enter pregnancy already depleted, and supports the rapid physiological changes that occur very early on, often before symptoms even begin.

Early supplementation isn’t about being “extra prepared”.
It’s about being aligned with how early pregnancy actually works.

Which Nutrients Are Worth Starting Early (and Why)

Not all nutrients play the same role in preconception health. Some are critical right at the start, while others help prepare the body over time.

Folate (Folic Acid or Active Folate Forms)

Folate supports DNA synthesis, cell division and early development.

Adequate folate levels before conception are strongly associated with a reduced risk of neural tube defects (specifically 400 mcg of Folic Acid at least one month prior to conception). Because neural tube closure happens so early, folic acid is consistently recommended as a preconception nutrient, not just a pregnancy one.

Iodine

Iodine is essential for thyroid hormone production, which plays a key role in early brain and nervous system development.

Even mild iodine deficiency before pregnancy can impact maternal thyroid function, which is why iodine is routinely recommended during pregnancy and breastfeeding, ideally with sufficient levels established before conception.

Iron

Iron needs increase significantly during pregnancy, but many women begin pregnancy with low iron stores.

Supporting iron status preconception (where needed) may help:

  • Reduce the risk of iron deficiency in early pregnancy

  • Support expanding blood volume

  • Lower the likelihood of fatigue and anaemia later on

Vitamin D

Vitamin D supports immune health, bone development and overall wellbeing.

Low vitamin D status is common, particularly in those with limited sun exposure. Correcting deficiency before pregnancy is often easier than trying to replete levels once pregnant.

Omega-3 Fatty Acids (DHA/EPA)

Omega-3s,  particularly DHA, support early brain and eye development.

Maternal omega-3 status before and in early pregnancy contributes to fetal stores, which is why adequate intake is often encouraged preconception rather than trying to catch up later.

Co-enzyme Q10 (CoQ10)

CoQ10 plays a role in mitochondrial energy production and acts as an antioxidant.

Emerging fertility research suggests CoQ10 may support:

  • Egg quality

  • Ovarian response

  • Embryo quality

This is particularly relevant in preconception conversations, as egg development occurs over approximately three to four months. While CoQ10 isn’t part of standard government prenatal guidelines, it’s commonly discussed in fertility-focused care and research settings.

So… When Should You Start?

A practical, real-world answer looks like this:

  • Thinking about pregnancy or open to it:
     Starting a prenatal now is reasonable and evidence-supported.

  • Actively trying to conceive:
     Aim to have been taking a prenatal for at least one month, ideally closer to three months.

  • Already pregnant:
     Start as soon as possible, the benefits extend well beyond the first trimester.

The Takeaway

Prenatals aren’t just for pregnancy, they’re part of preparing for pregnancy. Starting earlier helps ensure your body is nutritionally supported for:

  • Very early foetal development

  • The rapid changes of early pregnancy

  • The demands that begin long before most people realise they’re pregnant

If pregnancy is on your radar, now or “sometime soon”, that’s usually the right time to start. Important note: Not all prenatals are specifically developed for the preconception stage. Some only cover basic pregnancy needs and may not provide the optimal levels of nutrients needed before conception to support fertility, egg quality, or early foetal development. Choosing a prenatal formulated for preconception and pregnancy ensures your body is fully supported from the very first step of your journey.

FAQs

Is it safe to take a prenatal if I’m not actively trying to conceive?

Yes. Many prenatals, including Complete Support are designed to support increased nutrient needs during reproductive years. That said, individual needs vary, so it’s important to choose a prenatal appropriate for preconception use.

What if my pregnancy wasn’t planned?

You haven’t “missed your chance”. Starting a prenatal as soon as you find out you’re pregnant is highly beneficial and strongly recommended.

Do I need a prenatal if I eat a healthy diet?

A balanced diet is essential, but certain nutrients, particularly folate and iodine, are difficult to consistently meet at pregnancy-level requirements through food alone. A prenatal helps bridge that gap.

Should partners also think about nutrients preconception?

Yes. Sperm development occurs over roughly two to three months, and nutritional status can influence sperm quality. Preconception health isn’t just a maternal conversation.

All content and media on the Mother Natal website are created and published online for informational purposes only. It is not intended to substitute professional medical advice and should not be relied on as health or personal advice.

References

Dorney, E., Black, K. Preconception care. The Royal Australian College of General Practitioners (RACGP). Australian Journal of General Practice. https://www1.racgp.org.au/ajgp/2018/july/preconception-care

Australian Government. Pregnancy Care Guidelines. https://app.magicapp.org/?language=bo#/guideline/jm83RE

NHMRC. Folate and healthy babies. https://www.nhmrc.gov.au/about-us/resources/impact-case-studies/folate-healthy-babies

World Health Organization. Periconceptional folate supplementation. https://www.who.int/tools/elena/interventions/folate-periconceptional

Jiang, Yu and Han, Yao and Qiao, Pengyun and Ren, Fa. Exploring the protective effects of coenzyme Q10 on female fertility. Frontiers in Cell and Developmental Biology, Vol 13, 2025.  https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2025.1633166

Fleming TP., Watkins AJ. et al. Origins of lifetime health around the time of conception: causes and consequences. Lancet. 2018 May 5;391(10132):1842-1852. https://pmc.ncbi.nlm.nih.gov/articles/PMC5975952/

 

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