Healthy Eating In Pregnancy

How do I eat well during pregnancy?

All pregnant women need a healthy, balanced diet that includes a good range of fresh vegetables, fruit, dairy, meat or alternative proteins, and wholegrains.

Both over-nutrition and under-nutrition can cause problems for fetal development.  If you are concerned about your nutrition, consider seeing a dietitian for professional guidance.  Avoid fad diets, as these are often overly restrictive, lack sufficient nutrients and lack evidence of benefit.

 

Diet in pregancy dr colin walsh

 

What foods should be avoided during pregnancy?

Some foods carry an increased risk of food contamination and fetal infection. Avoid the following foods:

  • Raw or under-cooked meat, fish and poultry
  • Unpasteurised dairy products and soft cheeses
  • Unwashed or pre-cut, pre-packaged fruit and vegetables
  • Processed or delicatessen meats and pate
  • Excessive caffeine (max 1-2 cups daily)
  • Fish containing mercury: swordfish, shark, mackerel
  • Homemade meringue, mayonnaise, ice cream or anything that might contain raw or under-cooked egg

You should also follow these general principles of food preparation and storage:

  • All meat, fish and poultry should be cooked to the recommended “well-done” temperature and eaten while still hot
  • Avoid reheated leftovers, bains-marie and warming pans (e.g. at buffets)
  • Wash all fruit and vegetables well prior to preparation
  • Only eat freshly prepared food – avoid pre-made salads, pre-cut fruit, pre-packaged sandwiches etc

How much weight should I gain during pregnancy?

The answer to this common question depends primarily on what your Body Mass Index (BMI) is at the start of pregnancy.  Your BMI is your weight (kg) divided by height-squared (m2).  A normal BMI is 18.5-25 kg/m2.  It is not a perfect measurement but it is the one used most commonly worldwide.
In general, women with a higher BMI at conception should not gain as much weight during pregnancy as those who are underweight:

Pre-pregnancy body weight Recommended weight gain
Underweight (BM! <18.5) 13 – 18kg in total
Normal weight (BMI 18.5-24.9) 12 – 16kg
Overweight (BMI 25 – 29.9) 7 – 12kg
Obese (BMI > 30) 5 – 7kg
Morbidly obese (BMI > 40) < 5kg

Why does it matter?

Excessive weight gain while pregnant increases your risk of:

  • Gestational diabetes
  • High blood pressure / pre-eclampsia
  • Excess fetal birth weight
  • Blood clots in the legs or lungs
  • Slow progress in labour
  • Requiring an emergency caesarean section
  • Difficult epidural insertion
  • Wound infection if a caesarean is needed
  • In addition, children born to women with excess weight gain have a higher rate of childhood obesity

Vitamins & Minerals

I have published a chapter in a medical textbook on dietary advice in pregnancy[1]. Some of the key points to remember are:

  • Pre-conceptual folate (400mcg) is recommended for all women, commencing 3 months prior to conception and continuing to at least the end of the first trimester
  • Women who are at high risk of neural tube defects and women who are at risk of folate deficiency may need high-dose folate supplementation (5mg/day). Please discuss this with your doctor.
  • An extra 200 Calories intake per day are needed during pregnancy
  • Calcium supplements (1g per day) may reduce the risk of pre-eclampsia, especially in women at high-risk
  • Daily iodine intake of 220mcg is recommended
  • Pregnant women need approximately 27mg/day iron (higher than non-pregnant women)
  • Omega-3 fish oils are beneficial for maternal health but do not seem to improve fetal neurological development [2]
  • Avoid supplements containing high doses of vitamin A (retinoic acid) which can cause birth defects

Remember – the recommended daily intake of vitamins and minerals also includes normal dietary intake.  Women with a healthy, balanced and varied diet should receive enough iodine, vitamin D and calcium without needing to take a multivitamin tablet.  However, all women should take a folate supplement.

Women on restricted diets (e.g vegetarians and vegans) and women with bowel problems affecting the absorption of nutrients may need specific advice from their doctor or dietitian.

Some women find it difficult to ensure their diet contains all the essential vitamins and minerals.  These women may prefer to take a multivitamin.  It is important to take a multivitamin that is designed specifically for pregnancy.

We are often asked which pregnancy multivitamins contain appropriate amounts of the key nutrients.  While we do not endorse any particular brand, the most commonly used formulations in Australia are Elevit Pregnancy and Blackmores Pregnancy & Breastfeeding Gold.  Both of these supplements contain appropriate amounts of folate and iodine.  Elevit contains a much higher amount of iron, which can sometimes cause stomach upset.  Women who are not anaemic and who are prone to constipation may find the Blackmores formulation easier to tolerate.

1.   Walsh CA, McAuliffe FM. Dietary Therapy of Gestational Diabetes. In: Petry C. ed. Gestational Diabetes: Origins, Complications and Treatment. CRC Press, 2014: 119-146.
2.   Makrides M et al. Four-year follow-up of children born to women in a randomized trial of prenatal DHA supplementation. JAMA. 2014; 311: 1802-4.