Why Nutrition Before and During Pregnancy Matters

The nutritional status of the mother influences:

• Fertility
• Placental development
• Fetal growth
• Brain development
• Birthweight
• Long-term risk of obesity and metabolic disease

The “first 1,000 days” — from conception to age two — is considered a metabolic programming window.

That means what happens here has long-term consequences.

This is not about perfection.

It’s about protecting a sensitive developmental period.

Preconception Nutrition... What To Focus On

1. Achieve a Healthy Weight Before Pregnancy

Being overweight or obese before pregnancy increases risk of:

• Pre-eclampsia
• Gestational diabetes
• Thrombosis
• Emergency caesarean section
• Premature birth
• Miscarriage
• Stillbirth
• High birthweight
• Future obesity and diabetes in the child

Being underweight increases risk of:

• Miscarriage
• Preterm birth
• Low birthweight
• Gastroschisis

Preconception is the time to optimise weight and metabolic health.

Pregnancy is not the time to diet.

2. Take the Right Supplements

Two supplements are universally recommended:

• Folic acid 400mcg daily
• Begin 2–3 months before conception and continue until 12 weeks pregnant
• Reduces neural tube defects by up to 70%
• Vitamin D 10mcg daily
• Continue throughout pregnancy and breastfeeding

Avoid:

• Vitamin A supplements
• Fish liver oils
• High-dose multivitamins

These can increase risk of fetal abnormalities.

3. Reduce or Eliminate Alcohol

There is no known safe level of alcohol during pregnancy.

Alcohol is associated with:

• Miscarriage
• Premature birth
• Altered brain development
• Stillbirth
• Foetal alcohol syndrome

If planning pregnancy, it is safest to avoid alcohol entirely.

Heavy drinking in men also affects sperm quality and fertility.

Nutrition During Pregnancy

Do You Need to “Eat for Two”?

No.

Energy requirements:

• No additional calories in the first two trimesters
• ~200 extra calories per day in the third trimester

The focus should be diet quality — not calorie excess.

What Should a Healthy Pregnancy Diet Include?

A varied, balanced diet including:

• Protein sources (meat, fish, eggs, legumes)
• Dairy or calcium-rich alternatives
• Iron-rich foods (e.g. red meat)
• Fibre-rich foods
• Oily fish (within safe limits)
• Adequate hydration

Iron is particularly important for:

• Placental growth
• Expansion of maternal blood volume
• Preventing anaemia

Women are screened during pregnancy for iron deficiency.

Foods to Avoid or Limit in Pregnancy

Avoid:

• Soft mould-ripened cheeses (unless cooked)
• Unpasteurised dairy
• Raw or undercooked meat
• Raw shellfish
• Liver and pâté
• Shark, marlin, swordfish
• Raw eggs (unless British Lion stamped)

Limit:

• Tuna (max 2 fresh steaks or 4 cans per week)
• Oily fish (max 2 portions per week)
• Caffeine (max 200mg per day)

High caffeine intake is associated with miscarriage and low birthweight.

These restrictions reduce risk of:

• Listeriosis
• Salmonella
• Toxoplasmosis
• Mercury toxicity
• Neural developmental disruption

Gestational Diabetes

Gestational diabetes is caused by increased insulin resistance during pregnancy.

It affects around 5% of pregnancies and is more common in women with higher BMI.

Risks include:

• Larger babies
• Delivery complications
• Premature birth
• Increased risk of type 2 diabetes later in life

Management includes:

• Dietary modification
• Physical activity
• Monitoring
• Sometimes medication

Exercise can help improve glucose control.

Constipation and Morning Sickness

Common pregnancy issues include nausea and constipation.

To help reduce constipation:

• Eat high-fibre foods
• Exercise regularly
• Increase water intake

Morning sickness affects up to 85% of women.

Helpful strategies:

• Small, frequent meals
• Plain carbohydrate-rich foods
• Ginger-containing foods
• Staying hydrated

Severe symptoms should be medically assessed.

Post-Pregnancy and Breastfeeding Nutrition

Breastfeeding Benefits

Breastfeeding reduces risk of:

• Childhood infections
• Obesity
• Asthma
• Diabetes
• Cot death

It reduces maternal risk of:

• Breast cancer
• Ovarian cancer
• Heart disease
• Osteoporosis

Energy Needs During Breastfeeding

Exclusively breastfeeding mothers may require around 300 extra calories per day.

Appetite is individual — eating should respond to hunger.

No special diet is required.

Calcium Requirements

Breastfeeding mothers require approximately 1250mg calcium per day.

If dairy is consumed, this usually equates to around five portions daily.

If dairy is avoided, alternative calcium sources should be prioritised.

Fluids

Breastfeeding increases thirst.

Drinking to thirst is sufficient.

Excess fluid intake does not increase milk supply.

Effective latch and frequent feeding are key.

What Can Pass Through Breast Milk?

Alcohol and caffeine pass into breast milk.

Recommendations:

• Limit caffeine to 200mg per day
• Avoid alcohol or limit to small amounts occasionally

The 5 Core Recommendations

If you take nothing else from this guide, take these five:

1. Optimise weight and metabolic health before conception

Extremes of BMI increase pregnancy risk.

2. Supplement correctly

400mcg folic acid preconception to 12 weeks.

10mcg vitamin D throughout pregnancy and breastfeeding.

3. Focus on diet quality, not “eating for two”

Nutrient density matters more than calories.

4. Avoid high-risk foods and substances

Reduce infection and toxin exposure.

5. Maintain moderate physical activity and hydration

Supports metabolic health and reduces complications.

Final Thoughts

Pregnancy nutrition should not feel overwhelming.

It should feel protective.

It should feel structured.

And it should be evidence-based — not influenced by fear-driven internet narratives.

If you’re planning pregnancy or currently pregnant and want personalised, evidence-based support rooted in physiology — not trends — you can reach out to work with me.

Because this period matters.

And you deserve clarity, not confusion.

References (PubMed Indexed)

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