top of page
  • Writer's pictureBeverley Mort

Early life nutrition Part 1: The importance of diet when planning a pregnancy

Whilst the NHS may advise taking a 400 µg folic acid supplement prior to getting pregnant and up to 12 weeks of pregnancy, cut out alcohol and keep to a healthy weight, as well as stopping smoking if you are a smoker, there is very little other dietary advice provided (NHS, 21 January 2020).

Being healthy prior to becoming pregnant is really important and often not given enough attention, and maybe not fully appreciated by those people who are planning a pregnancy but not yet pregnant. There could be an impact on the health of the foetus, the infant after birth and throughout its lifespan, if mum is not as nutritionally healthy as she could be at the point of conception. In this blog I aim to provide some advice on what new parents need to consider in terms of their diet and nutrition, prior to getting pregnant. I will write a part two follow up blog, which advises on diet when pregnant and breastfeeding.

A woman who is healthy at the time of conception is more likely to have a successful pregnancy and a healthy child, and many influences on a child’s health are set in place before pregnancy. You may also be surprised to learn that the health and lifestyle of the father is also important prior to conception. Even something like his dietary choices can indirectly effect the health of his baby, due to the fact that the mother’s behaviour is influenced by his. So for example if the father is overweight and follows an unhealthy diet, then the mother is likely to follow this same pattern. There are also some direct effects of poor diet on the father’s sperm quality that can cause low sperm count or other sperm abnormalities. That’s why it’s also important for the father to focus on a healthy diet and lifestyle as much as a woman when a pregnancy is in the planning.

So what are the key diet and lifestyle considerations when planning a pregnancy?


Obesity prior to pregnancy is a risk factor. An obese mum can increase the risk of a child being obese at 4-6 years. Maternal obesity has biochemical effects on the foetus that transfer into adulthood. Some direct risk factors of obesity in pregnancy on the infant include, malformations, premature birth, still birth and too high birth weight. On mum the risks are diabetes, and hypertension. Weight loss before pregnancy can also improve fertility. An obese father can also effect the health outcomes of his child. So what is the solution? There is no magic answer, an obese mum and dad, planning a pregnancy need to lose weight prior to conception, to get to within a healthy BMI range which is 18.5 – 29.5, to reduce risk factors.

There are many ways to do this, but as a nutritionist I advocate a healthy balanced diet focussing on lots of fruit and vegetables, wholegrains, nuts & seeds, low sugar and salt, lean meat and fish, no alcohol, plenty of fibre and water. Or if you are vegetarian or vegan ensure your plant protein levels are sufficiently high. What does this mean? Try to cut out the fast food, ready meals, unhealthy snacks and sugary drinks and replace with simple home cooked/prepared meals, sugar free drinks in moderation, and plenty of water. Cook with a variety of different coloured vegetables and different types of proteins (tofu, beans, lentils, Quorn, chicken, turkey, pork, beef, salmon, haddock, cod etc). Try to keep red meat consumption low at once or twice a week, and avoid processed meat. Adding regular exercise to your daily routine not only will improve your general health, but help you lose weight more effectively. Try a 45 minute brisk walk every day, swimming, jogging, aerobic exercise such as following an exercise video etc. Anything that keeps you moving makes you a little hot and out of breath.

Folic Acid

Folic acid is an important B vitamin, but it becomes super important when planning a pregnancy, this is because it is a critical nutrient for the neural tube formation and development in a foetus. The neural tube forms the spinal cord and is part of the nervous system. A neural tube defect is a cause of spina bifida. The neural tube is one of the first major developments in a growing foetus and occurs early on in pregnancy. It is therefore important that a woman planning a pregnancy is not deficient before she conceives and continues to ensure she is not deficient up to 12 weeks of pregnancy. It is therefore recommended that a woman planning a pregnancy take a 400 µg supplement 8-12 weeks before conceiving and 12 weeks after conception. A healthy balanced diet contains folic acid, but supplementation is suggested for pregnancy

Vitamin D

We manufacture most of our vitamin D from the effects of sunlight on the skin. It’s difficult to obtain vitamin D from the diet, unless you are consuming fortified foods such as cereals, plant milks and margarine, also in the UK we don’t always get enough sunlight to prevent deficiency, especially during the winter months. That’s why in the UK it is advised that adults take a 10 µg supplement from October to March. Year round supplementation is advised for those people who cover their skin for religious reasons, who are dark skinned, and for the over 65s, and anyone who doesn’t expose their skin to sunlight on a regular basis.

A developing foetus relies on the mother’s vitamin D status for its needs, so if a woman is deficient in vitamin D prior to pregnancy, the developing foetus already may cause health issues in the mother and itself if it cannot access vitamin D. It is emerging that vitamin D has many benefits in the body, but one of the well-known and critical functions of vitamin D is to regulate calcium levels. When vitamin D levels are low the parathyroid hormone causes release of calcium from the bone, which increases the risk of thinning of the bones and osteoporosis. If mother’s vitamin D levels are insufficient to support the foetus the baby could develop seizures due to hypocalcaemia, and rickets, whilst also compromising the mother’s bones as well.


You might not give this nutrient much thought day to day, but it is important for a healthy thyroid gland. Recent research in the UK has shown a mild deficiency in school girls and pregnant women (BDA, 2019). It is therefore becoming a concern that adult women are not getting enough iodine, this is particularly an issue for women of child bearing age, as iodine needs are higher for this group than for any other at any time.

The thyroid gland produces thyroxine T3 & T4, and needs iodine to function properly. Thyroxine T3, the active form, as well as being important for growth, development and metabolism, is important for brain and neurological development of a foetus. There is evidence to suggest that mothers with low iodine status gave birth to children with low cognitive skills at the age of eight, compared to children of mothers with sufficient levels of iodine. Children born to low iodine status mothers also were found to have impaired working memory, language and motor skills, had lower spelling scores at school, lower reading accuracy and lower verbal IQ at the age of eight (Bath, 2019)

The most common source of iodine in the diet is milk (non-organic). If you drink milk on a regular basis, you are likely not deficient. If though you follow a plant based diet for example, or are excluding dairy products from your diet, it’s important to choose fortified foodstuffs, such as fortified plant milks, fortified cereals, iodised salt etc.


If you are planning a pregnancy, try to be as healthy as possible prior to conception to help ensure you have a healthy pregnancy. The nutrients I have written about here are stand outs from all the nutrients you need to eat in a healthy balanced diet. If you want more help in following a healthy balanced diet in preparedness for pregnancy, please contact me and we can assess your current diet and make changes as necessary to ensure you are getting all the vital nutrients well in advance of a pregnancy. In my next blog I will talk about the nutrients and foodstuffs you need to eat whilst pregnant and breastfeeding to help make sure mum is as healthy as possible and baby is too.


Bath, S (2019, September 11). Iodine Deficiency in the UK. Who is at Risk? [Webinar]. In Nutrilicious Nutriwebinar. Retrieved from

BDA (2019, May). Iodine Facts. Retrieved from

NHS (21 January 2021). Planning your pregnancy. Found Accessed 28 April 21

Recent Posts

See All


bottom of page