The 90-day fertility window: why prep starts before you start trying
Fertility doesn’t begin the month you start trying. The 90 days before conception can influence both egg and sperm health, making it a key window for preparation.
There’s a moment that happens for so many people. You decide you’re ready to start trying for a baby. Maybe quietly. Maybe after years of saying “not yet.” Maybe after upgrading period tracking apps and opening ovulation trackers for the first time. And naturally, the instinct is to think: okay, now we start trying.
But here’s the thing nobody really talks about enough: fertility doesn’t begin the month you start trying to conceive, it begins around 90 days before that because both egg and sperm health are shaped long before ovulation or fertilisation ever happens.
“Those 90 days before conception can change everything," says Alison Hall, Registered Nutritional Therapist, Fertility Specialist and OVA’s Director of Nutrition. “It reflects a fundamental biological truth: both eggs and sperm take roughly three months to fully mature before they are ready for fertilisation. For sperm, this is the complete cycle of spermatogenesis. For eggs, it is the final stage of follicular development, in which the egg undergoes that critical maturation. The nutrients the cells are bathed in, lifestyle choices, stress levels, and sleep quality during this period all influence the quality of the cells that will, if conception occurs, become a baby. We don’t need perfection, but sometimes a helping hand can make all the difference.”
Because whether you’re actively trying, preparing for IVF, thinking about future fertility, or simply wanting to understand your body better, reproductive health isn’t something that suddenly starts the day you see a positive pregnancy test. It starts long before that.
For information on infertility, read our articles on male and female infertility.
So, what actually happens during the 90-day fertility window?
One of the biggest misconceptions about fertility is that conception is purely about timing intercourse around ovulation. And while timing absolutely matters, there’s a much bigger biological story happening in the background. Eggs and sperm don’t appear overnight. An egg released during ovulation has actually been developing for approximately three months beforehand. Sperm development follows a similar timeline, taking around 70–90 days from formation to ejaculation. Which means the quality of both egg and sperm today is heavily influenced by what was happening in the body several months ago.
That includes everything from what you’re eating, hormone health to inflammation, sleep quality, alcohol intake, stress exposure, exercise habits, smoking, and environmental toxins. Which is why fertility specialists often recommend beginning supportive lifestyle changes and adding supplements around three months before trying to conceive or starting fertility treatment.
Why fertility prep matters for both partners
Fertility conversations are still disproportionately focused on women, despite the fact that male factor infertility contributes to roughly half of fertility challenges. Sperm health matters. A lot. And sperm are highly sensitive to lifestyle and environmental factors. Smoking, poor sleep, excessive alcohol, chronic stress, overheating, and nutrient deficiencies can all influence sperm count, motility, and morphology.
Yet prepping for preconception is still often framed as something women are expected to carry alone. She’s taking prenatals. She’s tracking her cycle. She’s changing her diet. But the reality is that conception is a shared process and recognising that small changes made together can have a meaningful impact.
The fertility foundations actually worth focusing on
“There is a persistent myth that a generally healthy lifestyle is enough”, says Hall. “Baseline health matters enormously, but the preconception phase has specific nutritional demands that diet alone often cannot meet”.
Unfortunately, there’s not one magical fertility diet. But there are nutrients consistently associated and studied for reproductive health support. “Folate (folic acid) is the example most people know, but the evidence now extends to vitamin D, B12, CoQ10, omega-3s, zinc, and selenium among others,” explains Hall.
What matters most are the basics: eating enough, eating consistently, prioritising nutrient density where possible, supporting blood sugar balance and adding in a good quality prenatal. And importantly, this applies to men too. Nutritional deficiencies can impact sperm health just as significantly as they can affect ovulation and egg quality.
“OVA’s targeted fertility support formulas, OVAHer Fertility & Pregnancy Support and OVAHim Advanced Sperm Support - are built around the logic of the 90-day window, providing targeted nutritional support during the period when egg and sperm quality is being shaped,” explains Hall. Rather than a generic multivitamin, they bring together all the key nutrients to optimise ovarian and testicular function in forms that the body can readily absorb and use.
OVAHer Fertility & Pregnancy Support was formulated to support hormone balance, egg quality, and reproductive wellbeing with evidence-backed ingredients including folate (folic acid), CoQ10, omega-3, antioxidants, and key micronutrients that support the body throughout the fertility journey. “For women, folate, ideally in its methylated form, remains the cornerstone because of its role in preventing neural tube defects and supporting healthy cell division. CoQ10 is increasingly recognised as important for mitochondrial function within eggs, and its relevance only increases with age. Vitamin D plays a vital role in ovulation, implantation, the health of the placenta and immune function, among others,” says Hall.
Meanwhile, OVAHim Advanced Sperm Support was developed specifically to support sperm health, motility, morphology, and overall male reproductive function. “For men specifically, zinc and selenium are foundational for sperm production and motility. CoQ10 supports sperm energy and protects against oxidative damage, which is a leading cause of poor sperm quality. Folate (folic acid) also plays a role in sperm DNA integrity.
Fertility is health, not just conception
Alongside nutrition, sleep and stress management are consistently underestimated. Chronic cortisol elevation can in fact disrupt the hormonal signalling that underpins a healthy cycle. So, what are easy wins to combat that? “Think of introducing daily micro-moments of calm,” advises Hall, “a walk, a quiet cup of tea, time away from your phone, these are not indulgences, they are part of the work.”
And sleep is one of the most underrated fertility support tools. Late-night scrolling, stress, work, cortisol spikes and constant stimulation all take its toll. And yet sleep plays a central role in hormone regulation, recovery, insulin sensitivity, testosterone production, ovulation health, and nervous system regulation. Poor sleep doesn’t automatically equal infertility, but chronically disrupted sleep can absolutely influence the systems fertility depends on. The aim is to give your nervous system a chance to slow down - think more consistency, earlier nights where possible and less stimulation before bed.
For too long, reproductive health advice has started at the positive test. But the biology doesn't and neither should the support. The 90 days before conception is really an opportunity to understand your hormones, address nutrient gaps when TTC (trying to conceive) with more clarity than chance. These foundations don't expire after conception either; they carry through into pregnancy, postpartum, and beyond. “You do not need to be perfect. It is about giving yourself the best possible foundation. And if you are doing those core things, you are doing enough,” says Hall.
Read our article on how to increase your chances of conceiving for more information.
Shop OVA's targeted fertility supplements to support egg and sperm health during the 90-day preconception window.
