How nutrition can optimise fertility and support a healthy pregnancy

Core Nutrition Dietitians

Sep 11

5 min read

Fertility is influenced by more than just genetics — what you eat, how you move and the nutrients you take in all play a powerful role in reproductive health. Nourishing your body before conception not only supports fertility but also lays the foundation for a healthy pregnancy and baby. The role of nutrition in fertility

Research shows that many women enter pregnancy with suboptimal intake of key nutrients — particularly long-chain fatty acids, protein, zinc, iron, and choline — all of which are essential for hormone regulation, egg quality, and overall reproductive health (Palomba et al., 2019; Chavarro et al., 2007).

Body weight also matters. Being either underweight or overweight can affect fertility. Obesity is associated with anovulation, infertility, miscarriage, and pregnancy complications, while too little body fat may disrupt hormone balance and compromise egg quality. Both men and women are encouraged to maintain a healthy weight and adopt balanced eating habits at least three months to a year before trying to conceive (Gaskins & Chavarro, 2018). Dietary patterns that support fertility

"Adequate protein is vital for reproductive health, supporting hormone production, egg quality, and fetal development."

The mediterranean diet The Mediterranean diet has been linked with improved fertility outcomes and higher pregnancy and live birth rates, especially in assisted reproductive treatments (Karayiannis et al., 2021). This dietary pattern focuses on:

Whole grains, fruits, and vegetables
Lean proteins (like fish and poultry)
Healthy fats from olive oil, nuts, and seeds
Low-fat dairy and plant-based proteins while limiting red and processed meats, refined carbohydrates, and added sugars.

Carbohydrates

Choose complex, high-fibre carbohydrate sources such as whole grains, legumes, vegetables, and fruit. These foods support healthy insulin regulation and reduce oxidative stress — both important for hormone balance and egg health.Limit refined grains, sweets, sugary drinks, and processed baked goods, which can negatively affect ovarian function and hormone regulation (Gaskins & Chavarro, 2018).

Protein

Adequate protein is vital for reproductive health, supporting hormone production, egg quality, and fetal development. Include a mix of lean meats and poultry (without skin), low-mercury fish (such as salmon, sardines, or trout), eggs, low-fat dairy and legumes. Plant-based proteins appear to positively influence fertility, while a high intake of processed meats may have negative effects (Chavarro et al., 2007). Avoid high-mercury fish such as swordfish, shark, and king mackerel, as mercury can impair reproductive outcomes.

Healthy fats

Healthy fats are essential for hormone production and reducing inflammation. Focus on monounsaturated fats: olive oil, nuts, seeds, and avocado, omega-3 fatty acids: oily fish or quality supplements. Trans fats and excessive saturated fats can increase insulin resistance and inflammation, potentially worsening conditions such as PCOS and endometriosis (Gaskins & Chavarro, 2018). Micronutrients and fertility

Vitamins and minerals play a vital role in reproductive health for both men and women, as well as in the healthy development of the fetus. They support key processes before and during pregnancy — including egg and sperm quality, fertilisation, embryo maturation and implantation. Deficiencies can negatively affect fertility and pregnancy outcomes, while a balanced diet can help prevent them. Supplements may be useful when dietary intake is inadequate, but excessive use should be avoided.

Key nutrients to consider:

Micronutrient	Role in fertility / preconception	Food sources
Vitamin A	Supports the production of male and female sex hormones and follicle development. Important for endometrial health. Avoid high doses of vitamin A (retinol).	Fatty fish, dairy products, egg yolks, orange & yellow vegetables and dark leafy greens.
Vitamin B12	Needed for DNA synthesis, egg and sperm quality, and to prevent megaloblastic anaemia. Low B12 in early pregnancy has been linked to neural tube defects and miscarriage risk.	Meat, eggs, dairy, fortified plant milks/cereals. Consider supplementing if you are vegan on vegetarian.
Vitamin C	May support sperm quality, though evidence for fertility improvement is limited.	Citrus fruit, berries, kiwi, papaya, melon, bell peppers and tomatoes.
Vitamin D	Involved in reproductive hormone regulation and ovarian function. Low levels are associated with poorer fertility outcomes. Consider testing and supplementing if deficient.	Fatty fish, egg yolk, fortified cereal, dairy and sunlight exposure (30min/day).
Folic acid (folate)	Essential for DNA synthesis and neural tube closure. Improves egg maturation and may increase pregnancy rates. Supplement with 400–800 µg/day from preconception	Dark green leafy vegetables, legumes, fortified bread and fortified cereal.
Iron	Required for ovulation and oxygen transport. Both deficiency and iron overload can impair fertility. Check iron levels before supplementing.	Red meat, dark green leafy vegetables and legumes. Pair with vitamin C to enhance absorption.
Calcium	No direct evidence if improving fertility, but calcium is essential in pregnancy. Important for maternal bone health and fetal skeletal development (especially in the 3^rd trimester).	Dairy products (yogurt, milk, cottage cheese, cheese), leafy vegetables, fortified cereals and fortified juice.
Zinc	Important for sperm development and ovulation. Low zinc is linked to reduced sperm quality.	Oysters, meat, chicken, wholegrains, legumes and nuts.
Iodine	Essential for thyroid hormone production, which is critical for fertility and fetal brain development.	Iodized salt, dairy products, eggs and seafood.
Magnesium	Involved in oestrogen and progesterone production and supports uterine blood flow. Deficiency has been linked to infertility.	Dark leafy vegetables, dairy, seeds, nuts and wholegrains.
Selenium	May influence egg maturation and sperm quality. Avoid high-dose supplements as excess intake can be toxic.	Brazil nuts, meat, fish and wholegrains.

Supplementation While a balanced diet is important, some nutrients may need additional support. Folic acid and vitamin D supplementation are widely recommended for women trying to conceive. Women at risk of deficiencies or with a current deficiency may benefit from supplements. A prenatal multivitamin and mineral supplement can help fill nutritional gaps but should always be discussed with a healthcare provider (Palomba et al., 2019). Lifestyle factors Lifestyle choices strongly influence fertility for both men and women. Limit alcohol, as excessive intake can disrupt menstrual cycles and reduce fertility. Avoid smoking, which can lower fertility by up to 60% and damage both egg and sperm quality. Caffeine in moderation is fine, but high intakes (more than five cups of coffee a day) may delay conception or increase miscarriage risk. Exercise regularly — moderate activity supports ovulation and sperm health, while excessive training can interfere with menstrual cycles (Gaskins & Chavarro, 2018).

Optimising fertility through nutrition is about creating balance — nourishing your body, supporting hormone function and preparing for a healthy pregnancy. Focusing on whole, nutrient-rich foods, maintaining a healthy lifestyle, and working with a qualified dietitian can help improve fertility outcomes and promote the health of both mother and baby.

References

Chavarro, J. E., Rich-Edwards, J. W., Rosner, B. A., & Willett, W. C. (2007). Dietary fatty acid intakes and the risk of ovulatory infertility. American Journal of Clinical Nutrition, 85(1), 231–237.Gaskins, A. J., & Chavarro, J. E. (2018). Diet and fertility: a review. American Journal of Obstetrics and Gynecology, 218(4), 379–389.Karayiannis, D., Vasileiou, A., & Panagiotakos, D. B. (2021). Mediterranean diet and reproductive outcomes: a systematic review. Nutrients, 13(12), 4305.Palomba, S., Orio, F., & Falbo, A. (2019). Preconceptional nutrition and fertility: evidence and recommendations. European Journal of Obstetrics & Gynecology and Reproductive Biology, 240, 201–208.World Health Organization (2023). Folic acid supplementation before and during pregnancy to prevent neural tube defects. WHO Guidelines.