Factors implicated in reducing the risk of pre-eclampsia (Recommended Dietary Allowance (RDA) included in column 1)
| Factor | Recommendation | Further relevant advice |
| Maternal weight | Excessive weight gain during pregnancy and between pregnancies should be avoided. Women should ideally be of a healthy body weight (BMI) prior to conception. Recommendations are that underweight women (BMI ≤18.5) should put on between 13 and 18 kg; normal-weight women (BMI 18.5–24.9) should put on between 11.5 and 16 kg; overweight women (BMI 25–29.9) should put on between 7 and 11.5 kg and obese women (BMI ≥30) should put on no more than 5–9 kg. | A woman aiming to reduce her BMI prior to pregnancy should do so safely preferably with the help of a suitable healthcare professional. |
| Fibre | A high-fibre diet is recommended for pregnant women and those at risk of pre-eclampsia. Women should aim for a fibre intake of 25–30 g/day to reduce the risk of pre-eclampsia. | Higher fibre intake can reduce blood cholesterol, blood pressure and inflammation and may also aid in weight management. |
| Prebiotics and probiotics | Consume milk-based probiotics where possible as part of a normal diet. | Further research is required to determine the quantity, timing and efficacy of probiotics to reduce pre-eclampsia risk. |
| Dietary patterns | Pregnant women should aim to consume ≥400 g of fruits and vegetables per day and ≥250 mg/day of docosahexaenoic/eicosapentaenoic acid by consuming ~230 g (8 ounces) of mixed seafood per week. High fat, salt, sugar foods and red and processed meats should be limited. | Avoid raw fish and fish with a high mercury content (shark, swordfish, king mackerel, tilefish, marlin, orange roughy, bigeye tuna) during pregnancy. |
| Vitamin D RDA 15 μg/day | Daily vitamin D supplement of 10–25 µg (400–1000 IU); stay well away from the upper limit of 100 μg (4000 IU). | A woman’s current vitamin D status can be measured and may be helpful in defining optimum dosage. |
| Calcium RDA 1000 mg/day | All pregnant women to be supplemented with 1 g calcium per day from 20 weeks’ gestation to delivery. Women at heightened risk of pre-eclampsia and/or with a low dietary calcium intake should take a calcium supplement of 1–2 g/day during pregnancy. | Calcium supplement, for example, carbonate or citrate. Women are likely to have low dietary calcium intake if they do not consume dairy products which are a major calcium source. |
| Selenium RDA 60 μg/day | Women who are likely to have low selenium status (eg, in the UK), should increase their intake of selenium-rich foods, such as fish/shellfish. Alternatively, they should take a multivitamin/multimineral containing selenium as soon as they know they are pregnant and preferably when planning pregnancy. | Brazil nuts are a good source of selenium but the dose can be very high, so it is a risky way of supplementing selenium. Keep intake down to four per week if taking regularly. |
| Multivitamins/multiminerals | Women should take a multivitamin/multimineral supplement containing folic acid, vitamin D (unless taking separately) and selenium (if status is low) if they are planning on becoming pregnant. If pregnancy is unplanned, the woman should start the supplement as soon as possible. The supplement should be taken for at least the first trimester. | This supplement may be of particular importance for those who are overweight. Iodine is important for fetal brain development and should be included for a woman who does not eat dairy products or fish in a country that does not have iodised salt. The usual dose in pregnancy is 150 μg/day, usually as potassium iodide. Avoid taking a kelp supplement. |
BMI, body mass index.