Weight and nutrition
A snapshot:
A healthy weight and good nutrition can improve your chances of conception
Men and women who are trying-to-conceive should follow a healthy, balanced diet – a Mediterranean-style diet has been shown to be ideal for fertility.
Weight and nutrition should ideally be optimised three months prior to conception, which is how long it takes for eggs and sperm to develop
Women should supplement with folic acid and iodine - most women need a folic acid supplement to achieve the levels known to reduce the chance of gross abnormalities such as spina bifida
Women with a BMI of more than 32 must lose weight in order to become eligible for publicly funded fertility treatment
Ideal BMI for fertility is between 20 and 25
Obesity in men is associated with infertility by causing impaired semen quality, decreased libido and erectile dysfunction
In women obesity decreases fertility and may be associated with conditions such as PCOS, and can also impact pregnancy health
Low body weight can prevent normal ovulation and may also reflect a poor nutritional status which can ultimately affect the health of the pregnancy and baby
Lifestyle
Good preconception health can improve chances of conception, a healthy pregnancy and healthy child.
Maturation of the sperm and egg takes 3–4 months, so ideally preconception health should be in place for this long.
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Recent studies report a world-wide decline in sperm number and quality over the past 50 years, although this seems to have leveled off in NZ over the past 15-20 years
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Men and women should follow a healthy, balanced diet – a Mediterranean-style diet has been shown to be ideal for fertility
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Avoid (or reduce) alcohol and caffeine consumption
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Women should supplement with folic acid and iodine - most women need a folic acid supplement to achieve the levels known to reduce the chance of gross abnormalities such as spina bifida
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Avoid recreational drugs and nicotine
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Exercise extreme caution when self-prescribing any medication or fertility device
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Maintain a healthy weight
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These factors are equally important for women and men
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Moderate exercise – too much or too little can be detrimental to your fertility
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Men should avoid increased testicular heat
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Avoid environmental toxicity as far as possible – in your home and work
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Proactively manage stress and prioritise self-care
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These lifestyle factors can also impact success of IVF
Weight
There is evidence that both female and male fertility are decreased by being either significantly overweight (obese) or underweight. It is recommended that people aiming to conceive naturally or with ART maintain a healthy body weight (BMI between 20 and 25).
Obesity in men is associated with infertility by causing impaired semen quality, decreased libido and erectile dysfunction.
In women obesity decreases fertility and may be associated with conditions such as PCOS, and can also impact pregnancy health. During pregnancy, being overweight or obese are associated with an increased risk of miscarriage, gestational diabetes, pre-eclampsia, premature births, stillbirths and perinatal mortality. The babies of overweight mothers are more likely to be obese and suffer cardiovascular disease and diabetes as adults. Thus, women with a BMI of more than 32 must lose weight in order to become eligible for publicly funded fertility treatment in New Zealand.
A 6-month group programme for overweight infertile women, which provided dietary and exercise advice alongside support to make healthy changes, was shown to be effective (1). The women had an average weight loss of 5kg and most of the women who did not ovulate resumed spontaneous ovulation.
Low body weight can prevent normal ovulation and may also reflect a poor nutritional status which can ultimately affect the health of the pregnancy and baby: Low maternal weight before pregnancy and poor weight gain during pregnancy are known to result in an increased chance of pre-term delivery and low birth weight infants.
(1) Kidd, S.A., Eskenazi, B., and Wyrobek, A.J.”, Effects of male age on semen quality and fertility: a review of the literature.” Fert. Steril. (2001) 75 (2): 237–48
Fertile Body Mass Index (BMI)
too low!
BMI <18
just right!
BMI 20-25
too high!
BMI >28
Nutrition
Eating a healthy diet in the three months preceding conception attempts can help protect DNA, promote sperm health and encourage and support a healthy libido. Recent research suggests that following a Mediterranean style dietary pattern increases the chance of conceiving per month.
A Mediterranean diet consists of lots of antioxidant rich vegetables and fruit, whole grains and legumes, monounsaturated vegetable oils, fish, poultry and dairy products. Transitioning to this diet involves reducing saturated fats and processed foods.