Nutrition in pregnancy- time for a diet and lifestyle change

Preconception advice
Although there are no national guidelines on how to give preconception support, straightforward risk-assessment, education and health promotion activities are generally considered beneficial: they may help to maximise the likelihood of healthy outcomes for the baby, their parents and older siblings¹. Specific nutritional/health preconception advice is routinely given to women with conditions such as diabetes, who are planning a pregnancy or are newly pregnant². Such advice helps to ensure that these women receive support that is appropriate during pregnancy and that their nutritional needs are adequately met.

But for adults with no major underlying health issues, following a healthy diet and lifestyle often enhances their ability to conceive, have a good pregnancy and give birth to a healthy child. Waiting until a health goal is reached (such as getting to a target weight) before stopping contraception can be a great incentive to a woman and her partner, when they want to start a family. However, in the UK it is estimated that only 50% of pregnancies are planned³. Consequently, it may be beneficial to offer preconception advice opportunistically, to all women of child-bearing age, during routine appointments (especially ‘well-woman’ or family planning services)⁴. Information can be provided in different formats (e.g. orally during the consultation, or through leaflets, audio-visual presentations or posters in the waiting areas), and in different languages, to suit local needs. Opening a dialogue about preconception health – and displaying information about it – alerts all patients about the importance of making lifestyle improvements before starting a family. Such promotions also remind adults that health and nutritional advice is always available from healthcare professionals, even if they have an appointment for another reason.

Smoking, alcohol and nutrition
Smoking and alcohol consumption are two obvious areas to discuss with prospective parents and pregnant women. Fertility, conception, survival of the conceptus, most phases of pregnancy and aspects of fetal development – together with the infant’s postnatal survival and health – are adversely impacted by maternal alcohol use, or tobacco exposure⁵. Both smoking⁶ and alcohol⁷ negatively affect vitamin C concentrations in mothers and their newborn babies. Low vitamin levels have been found in plasma samples taken from pregnant smokers, and may result in hyperhomocysteinemia, a known risk factor for several pregnancy-associated complications⁸.

Advice for men
Little attention has been paid to the preconceptional effects of diet in men, but it is always beneficial to follow a healthy, balanced diet, with alcohol in moderation and any weight issues corrected. Diets that have gross nutritional inadequacies or excesses can affect men’s fertility and the viability of the conceptus. For example, zinc, selenium and vitamin C are nutrients important for sperm motility and viability, but alcohol decreases the contribution of several vitamins and trace elements to immune-system function⁹.It is also important to remind men that dietary and lifestyle changes may take up to 3 months before any impact on sperm quality is observed. Regular alcohol intake increases risk of low birth weight, brain damage and fetal alcohol syndrome.

Well-nourished is not eating for two!
Following a well-balanced, nutritionally adequate diet is extremely important in pregnancy and while breastfeeding, for the short- and long-term well-being of both mother and baby¹⁰. Box 1 provides general guidance on dietary recommendations during preconception or pregnancy¹¹.


The healthier a woman’s diet is before she is pregnant, the better her health during pregnancy is likely to be. Compared with under- or overweight/obese women, those with a healthy pre-pregnancy weight have a lower risk of poor pregnancy outcomes including neural tube defects, gestational diabetes, hypertension, preterm delivery, Caesarean delivery, and thromboembolism^12,13.

Fat distribution and fertility
Fertility is closely associated with body size and composition. Normal ovulatory function and menstruation only occur when fat makes up at least 22% of a woman’s body weight¹⁴. Irregular menstrual cycles and reduced ovulation are commonly observed in women of low body weight, those with a history of eating disorders, or those who diet regularly. But there is literally a ‘happy medium’. When women exceed the average body fat levels of 26–28%, particularly if they are obese and have excess abdominal fat, a significant reduction in fertility is also observed¹⁵.

Body Mass Index (BMI) and pregnancy
Compared with women of a healthy pre-pregnancy weight, women underweight (BMI 16–19) before pregnancy are more likely to deliver babies of low birth-weight^13,14; women overweight (BMI 25–29) or obese (BMI > 30) before pregnancy are at greater risk of gestational diabetes, pregnancy-induced hypertension or pre-eclampsia, and are more likely to need emergency caesarean sections^13,14. The incidence of such complications increases as pre-conception BMI increases¹⁶.

Managing excess weight
Although it is better to begin a healthy-eating programme before conception, dietary changes can still be made during pregnancy, to help reduce the risk of complications and lead to long-term health improvements.

The average total weight increase during pregnancy is approximately 12kg, with an estimated 3kg being increased fat deposits, although there are no standard recommendations for weight gain. Nutritional requirements change during pregnancy, but calorific intake should remain normal (2000kCal per day) for the first and second trimesters. For the third trimester, the mother’s intake should increase by 200kCal per day, which equates to two snacks (such as a small bowl of fortified cereal and a banana)¹⁷. While breastfeeding, the recommended increase is 500 kCal per day, although this can be as low as 120kCal/day extra for women who want to lose weight¹⁷.

To avoid unnecessary weight gain, women who are overweight or obese at booking-in should be encouraged to follow healthy diets, based on the normal requirements for women (2000 kCal per day; Box 1)¹⁷. This may mean that you are advising them to consume fewer calories – and smaller portions – than they were previously used to, therefore such women would benefit from tailored dietary advice and support, ideally from a Registered Dietitian.

The goal is to encourage all pregnant women to consume well-balanced diets that are of maximum nutritional value (Box 2). Swapping energy-dense, nutritionally poor foods for fortified cereals, or swapping white bread for wholemeal, are simple steps that can improve the quality of their diets without leaving women hungry.

Box 2 provides specific advice on key nutrients and RNI values in pregnancy^17,18. Pregnant women should be led by their appetite, eating only when hungry: little and often may be better, especially if nausea or indigestion are problematic. Large amounts of fatty or sugary food should be avoided, and if salt is required it is better added at the table rather than during food preparation.



Folic Acid
Women planning a pregnancy or who discover they are pregnant should consume a folate-rich diet, to help reduce the risk of neural tube defects, behavioural problems¹⁹, and orofacial clefts²⁰.

Several foods are good sources of folic acid (Box 2), although folic acid supplements are also widely available. The dosage recommended for most women trying to conceive is 400 μg (micrograms)/day. Ideally, folic acid supplementation should begin as soon as the woman decides to plan a pregnancy, because its effects on reducing the risk of neural tube defects are likely to be most apparent very soon after conception, before the woman realises that she is pregnant. However, folic acid supplementation remains beneficial throughout the first trimester, so it should still be taken as soon as pregnancy is suspected or confirmed^17,19.

Women in whom a previous pregnancy was affected by a neural tube defect, women with diabetes (or history of gestational diabetes) or renal disease, and women taking anti-epileptic medications require higher-dose (5mg/day) folic acid supplement, which is available on prescription.

Encouraging behaviour change
Individuals change behaviour in response to different triggers. Some are motivated to alter nutritional habits simply to give their baby the best possible start; others want to limit the long-term negative impact of any pre-existing dietary/lifestyle issues. To judge what motivates a person to change, it can be useful to use techniques common to smoking cessation strategies, such as answering questions using a visual 0–10 scale (with 0 being of no importance, and 10 being of utmost importance). Several useful resources are available to assist Healthcare Professionals when providing weight loss support (Box 3).



Good nutritional strategies
Anyone who is overweight will benefit by increasing their level of physical activity. But being ‘busy’ is not necessarily being ‘active’. The key is to increasing one’s level of exertion. Even in pregnancy – especially in the second trimester, if tiredness is a problem in the early weeks – walking a little further or taking the stairs, not the lift, raise a woman’s activity level.

Always encourage people to eat breakfast – skipping breakfast does not lead to weight loss! Overnight is a long time without food and blood sugar levels may be low in the morning. It`s a good idea to boost energy levels with slow releasing carbohydrates like porridge or brown toast. A bowl of fortified cereals is a quick meal that provides important vitamins and minerals, which are particularly important for pregnancy.

There are several easy ways to reduce the empty calories in a person’s diet, such as:

• Reduce, or stop taking, sugar in hot drinks
• Swap sugary soft drinks for low-calorie varieties (or better still, water)
• Reduce the consumption of ‘smoothies’ or fruit juice (whole fruit is better)
• Swap crisps or chocolate for fortified cereals, fruit or nuts/seeds
• Look at portion size (which is often under-estimated). Eating 10 fewer chips or one fewer chocolate biscuit equals 100 fewer empty calories!

Eating and drinking in labour
Local hospital policies dictate whether (and what) women are permitted to eat and drink during active labour. In many cases the situation depends on the woman’s risk status at term. A prospective, randomised trial involving over 2000 nulliparous low-risk non-diabetic women concluded that consuming a light diet during labour did not influence obstetric or neonatal outcomes, or increase the incidence of vomiting²¹. Labour length and operative delivery rates were similar in women, regardless of whether they consumed a light diet or fluids only²¹
In a normal labour, eating during labour is usually left up to mum.

Conclusions
Preconception and pregnancy herald social, psychological, behavioural and biological changes in a woman’s life, and represent times when women are likely to be receptive to healthy diet and lifestyle messages. Any opportunity to support people of child-bearing age who want to adopt a healthier lifestyle should be grasped by Healthcare Professionals, for the benefit of the adults themselves as well as any children they go on to have.


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References

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