Healthy Pregnancy: Diet, Exercise, Lifestyle & Daily Decisions
What you eat, how you move, and how you live during pregnancy matters — but the actual rules are simpler than the internet suggests. Here is what the evidence genuinely says.
🌿 Open full lesson in WiseMama — free, with quizzes & flashcardsThe Two Supplements You Actually Need
Walk into any pharmacy and you will find a wall of pregnancy supplements promising everything. The NHS recommends two — and both have robust evidence behind them.
Folic acid (400mcg daily, from before conception to week 12)
Folic acid reduces the risk of neural tube defects — conditions affecting the brain and spinal cord that form in the first weeks of pregnancy — by up to 70%. The NHS recommends 400mcg daily from at least three months before conception through to week 12. If you are already pregnant and have not started, begin immediately. Even a few weeks of supplementation matters. A higher dose of 5mg is prescribed if you have a personal or family history of neural tube defects, take anti-epileptic medication, or have certain metabolic conditions — your GP can arrange this.
Vitamin D (10mcg daily, throughout pregnancy and breastfeeding)
Most people in the UK do not produce sufficient vitamin D from sunlight, particularly between October and March. During pregnancy, vitamin D supports fetal bone development and immune function. 10mcg (400 IU) daily is the recommendation throughout pregnancy and breastfeeding. It is inexpensive, available without prescription, and if you are on low income or receiving certain benefits, Healthy Start vouchers cover it.
Everything else
Iron supplementation is recommended if blood tests reveal anaemia, which is common in the second and third trimesters. Omega-3 DHA (from food or algae-based supplements) supports fetal brain development. Iodine is important for thyroid function and fetal development and is found in dairy, white fish, and eggs — often low in vegan diets. Do not take high-dose vitamin A supplements or liver oil products during pregnancy.
What to Eat During Pregnancy
The phrase "eating for two" is one of the more persistent myths in pregnancy. Caloric requirements increase only modestly — around 300 extra calories in the second trimester, and 500 in the third. What matters far more than quantity is quality, particularly protein, calcium, iron, folate, and iodine.
A practical approach: include a protein source at every meal, prioritise dairy or fortified plant alternatives for calcium, choose iron-rich foods and pair them with vitamin C to improve absorption, and base your diet on whole foods rather than supplements where possible.
- Protein — meat, fish, eggs, dairy, legumes, tofu. Essential for fetal growth.
- Calcium — dairy products, fortified plant milks, leafy greens, sardines with bones. Critical for fetal bone and tooth development.
- Iron — red meat, fortified cereals, lentils, dark leafy greens. Eat with vitamin C. Avoid tea or coffee with meals, which inhibit iron absorption.
- Folate — dark leafy greens, legumes, fortified cereals. Supports the supplemental folic acid you are already taking.
- Omega-3 DHA — oily fish (up to two portions weekly), algae-based supplements for those who avoid fish.
What to Avoid, Limit, and Not Worry About
The actual NHS list of foods to avoid is considerably shorter than most online sources suggest — and a great deal of the anxiety around pregnancy food is based on misread or overstated guidance.
Avoid completely
- All alcohol — no safe level is established in pregnancy
- Raw or undercooked meat and poultry
- Unpasteurised mould-ripened soft cheeses (Brie, Camembert) and blue-veined cheeses
- Liver and liver products — excess preformed vitamin A
- Shark, swordfish, and marlin — high mercury
- Raw shellfish
Limit
- Caffeine: under 200mg per day — roughly one filter coffee, two instant coffees, or four cups of tea. Also present in energy drinks (avoid entirely), cola, and chocolate.
- Oily fish: maximum two portions per week
- Tuna: maximum four medium tins or two fresh steaks per week
What you can eat — the myths worth clearing up
- Smoked salmon — safe throughout pregnancy
- Runny eggs — safe if Lion Mark British eggs. The Lion Mark certifies Salmonella vaccination.
- Pasteurised soft cheeses — safe. Only unpasteurised and mould-ripened varieties are restricted.
- Sushi — safe if made with previously frozen fish, as required by UK food safety regulations for commercial sushi.
I asked my midwife the smoked salmon question at week 10 and she looked at me like I was bonkers. 'You can eat it.' I had been making myself miserable over food rules I'd misread. Get the NHS guidelines and read them properly — the actual list is much shorter than the internet would have you believe.
Exercise During Pregnancy
The evidence on exercise in pregnancy has shifted significantly in recent years. Regular moderate physical activity is now understood to be actively beneficial — not something to be cautious about, but something to seek out. It is associated with better birth outcomes, reduced gestational diabetes risk, lower likelihood of excessive weight gain, improved mood and sleep quality, and faster postnatal recovery.
The NHS recommends 150 minutes of moderate-intensity exercise per week, spread across at least three days. "Moderate intensity" means your heart rate and breathing increase, but you can still hold a conversation. If you were not previously active, start with 15-minute walks and build gradually — there is no rush.
What is safe
- Walking, swimming, static cycling, pregnancy yoga, Pilates with a pregnancy-aware instructor, light resistance training, dancing
- Most activities you were doing before pregnancy, adapted as your bump grows
What to avoid
- Contact sports with risk of abdominal impact
- High fall-risk activities — horse riding, skiing, gymnastics
- Scuba diving
- Lying flat on your back for extended periods from the second trimester onward
- Exercising in excessive heat, or using saunas and hot tubs
I swam three times a week until 38 weeks. It was the only thing that didn't make my pelvis hurt, the water made me feel weightless, and I slept better on swim days. If you can access a pool, just go.
Daily Life, Travel, and Work
Most everyday activities are safe throughout pregnancy, and understanding the specific exceptions means you can carry on with normal life rather than approaching everything with unnecessary caution.
Sex
Sex is safe throughout an uncomplicated pregnancy. Your baby is protected by the amniotic sac and cervical mucus plug. There is no evidence that orgasm triggers miscarriage in healthy pregnancies. The exceptions are if you have placenta praevia, unexplained bleeding, or have been specifically advised otherwise by your midwife.
Travel
Flying is generally safe until week 36 for single pregnancies and week 28 for multiples — though individual airline policies vary and are worth checking before you book. Wear compression socks on any flight over four hours and walk regularly. For long-distance car or train journeys, stop every two hours to walk and stretch. Destinations affected by Zika virus should be avoided — check the FCDO and NHS Fit for Travel guidance before booking anything international.
Work
Your employer is legally required to carry out a pregnancy risk assessment and address any risks identified — including physical demands, chemical exposure, extended standing, and working hours. If reasonable adjustments cannot be made, you must be suspended on full pay. You also have the right to paid time off for all antenatal appointments, including scans and midwife checks, regardless of how many hours you work or how long you have been employed.
Most evidence suggests hair dye is safe during pregnancy, and the NHS states there is no evidence that colouring your hair causes harm. Many people choose to wait until after the first trimester as a precaution. Highlights and balayage, where dye does not contact the scalp, carry even lower theoretical risk. If you have concerns, discuss them with your midwife.
Saunas and hot tubs should be avoided during pregnancy. High core body temperature in the first trimester has been associated with an increased risk of neural tube defects. Later in pregnancy, overheating can cause dizziness and dehydration. Warm (not hot) baths are fine.
Yes, unless you have a personal peanut allergy. The previous NHS recommendation to avoid peanuts during pregnancy was withdrawn in 2009. Current evidence suggests that eating peanuts during pregnancy may reduce, rather than increase, the risk of peanut allergy in the child. The NHS no longer recommends avoiding any allergenic food during pregnancy.
Healthy weight gain depends on your pre-pregnancy BMI. General guidance: underweight (BMI under 18.5) — 12.5–18kg; healthy weight (18.5–24.9) — 11.5–16kg; overweight (25–29.9) — 7–11.5kg; obese (30+) — 5–9kg. Rather than tracking weight, focus on eating nutrient-dense food and exercising moderately. Your midwife monitors fundal height as a more reliable guide to fetal growth than the number on your scales.