Current Nutritional Guidelines
Current NICE guidelines and recommendations ensure that health professionals involved in antenatal care are effectively trained to give the correct advice and support to mothers regarding their nutritional need’s prior, during and post pregnancy. Health professionals are to give practical food based advise to enable pregnant women to create and sustain healthier choices with their diet and physical activity. For antenatal health, it is recommended that at least 5 portions of fruit and vegetables are consumed daily and one portion of oily fish weekly i.e. mackerel, sardines, trout or salmon. Women who are planning to conceive or are in their first 12 weeks of pregnancy are advised to supplement 400micrograms of folic acid alongside eating folate rich foods such as peas, beans and fortified cereals. Calorie intake needs to increase by around 340calories per day when the woman enters her second trimester or around 600 calories if she has a twin pregnancy.[1] If a woman has a BMI over 30, health professionals are instructed to refer her to a dietician for assessment and support with healthy eating and exercise. Although weight loss shouldn’t be encouraged during the pregnancy, a structured plan is to be put in place for the mother following the birth of her child to adopt healthy lifestyle changes.
The initiative Healthy Start to increase public health and is aimed at eligible women in early pregnancy and parents of children under 4 years old. Health professionals should promote this at every opportunity and distribute forms to the relevant patients and fully inform them of the benefits they can provide for their health. Healthy start provides vouchers to increase the daily intake of fruit and vegetables and provide free healthy start vitamins which contain folic acid, vitamin D and vitamin C for pregnant woman.[2]
Maternal malnutrition can have both short- and long-term effects on the maternal and foetal health and can also cause birth complications such as preterm birth and low birth weight. Improving maternal nutrition can prevent complications and increase the chances of better management of the pregnancy outcomes. Some barriers that women can experience in nutrition are cultural, financial, accessibility, poor education and poor support networks. These guidelines have been put in place to counteract these barriers however, individual circumstances may still provide some difficulties for these women to fully reach their nutritional needs.[3]
ABCDs
Using the ABCDs: anthropometric, biochemical, clinical and dietary measurements you can gain a detailed insight into the health of the women you are advising. Nutrition is vital to maintaining a healthy weight and preventing chronic conditions such as heart disease and diabetes along with having the ability to increase healing and recovery times. Completing this nutritional assessment can identify whether your client is experiencing malnutrition and allows you to discover whether they have any micronutrient deficiencies or excesses.[4] These assessments are also useful to indicate risk levels of conditions that are linked with pregnancy such as pre-eclampsia, gestational diabetes, venous thromboembolism and anaemia.[5]
Anthropometrics
Anthropometric assessments allow us to gain insights into the maternal body composition and the changes that occur during the pregnancy. Body mass index (BMI) is most used alongside monitoring gestational weight gain (GWG) as they are non-invasive and easily measured through the duration of pregnancy, studies have shown that GWG is related to foetal growth and birth weight. When GWG is either above or below the expected range, a link has been made to a higher risk of intrauterine growth retardation (IUGR), low birth weight and premature births. The expected ranges for GWG are based on the mothers pre pregnancy BMI and together they show a positive correlation for determining birthweight.
Although these methods are useful in monitoring the progression and identifying risks of pregnancy, they provide an incomplete picture of the mother’s health as they do not provide any information on the maternal body composition and how this may influence the maternal and foetal health.
Subcutaneous fat tissue (SFT) skinfold assessments display a high correlation of body fat percentage with techniques such as DEXA, which are highly accurate but not safe for use during pregnancy due to radiation. SFT assessments are a quick, reliable and non-invasive measure that can add valuable information when monitoring a woman’s health throughout gestation. The limitations of SFT are that later in pregnancy it can become difficult to gain measurements from the abdominal region and sometimes may not be possible at all, some women also experience oedema which can affect the accuracy of the measurements taken.[6] To monitor the body fat changes throughout gestation, callipers can be used to measure the skin thickness and fat mass (mm) at the 4 recommended sites by ISAK: triceps, subscapular, biceps, supra-iliac. This calculation is used to gain the body fat percentage %Body fat= (0.29669 *sum of skinfolds)- (0.00043* square of the sum of skinfolds) + (0.02963* age) + 1.4072. [7]
It is expected for women to gain weight during pregnancy, the recommended weight gain for a woman with a healthy pre pregnancy BMI is 11.5-16kg. BMI can be calculated by collecting the women’s height and weight measurements and calculating the Weight (kg)/ Height (M2).[8]
Biochemical
Routine antenatal blood tests are recommended for women in early pregnancy. They are to determine the blood group of the mother if it is not already known, to screen for antibodies, rubella immunity, infectious diseases, viruses, rhesus factor and to perform a full blood count.[9]
A full blood count should be offered at early pregnancy booking appointment and at 28weeks. It determines the mother’s haemoglobin (Hb) levels, as low levels of Hb can be an indication of anaemia. There are three types of anaemia to occur in pregnancy: folate-deficiency anaemia, vitamin B12 deficiency and Iron-deficiency anaemia which is the most common form so will be detailed further. The minimum level of Hb occurring in pregnancy is 110 g/L, if levels are lower than this anaemia in pregnancy is declared. Mild iron deficiency is to be treated with the prescription of ferrous sulphate 200mg daily, if this is unsuccessful then parenteral iron should be administered in a setting with the required facilities due to the risk of anaphylactic reactions. [10] Iron is required to produce adequate amounts of Hb which transports oxygen to the tissues of the body. Folate is required to produce healthy red blood cells; a deficiency would result in the maternal body not creating enough cells to transport oxygen to the body tissues and can contribute to neural tube abnormalities such as spina bifida. A high folate diet is advised to pregnant women paired with folic acid supplements. Vitamin B12 is required to form health red blood cells, women who do not eat meat or dairy products are at greater risk of this deficiency. Low B12 could contribute to neural tube defects and preterm labour and supplements may be recommended if their diet is lacking. Anaemia is commonly presented in symptoms such as pale skin/lips, fatigue, dizziness, concentration problems and rapid heartbeat. [11]
If the woman is at risk of gestational diabetes or displaying symptoms, an oral glucose tolerance test is offered. This is performed after 8-10hours fasting and a blood test is taken in the morning, following this a glucose drink is administered. After 2 hours, another blood test is taken to monitor how their body metabolises glucose. When diagnosed with gestational diabetes, they will be advised to make dietary changes and increase gentle exercise such as walking to decrease their blood sugar levels. If there are no improvements, either oral medication or insulin injections will be prescribed to manage the condition along with a blood sugar testing kit. [12]
Clinical
Symphysis pubis dysfunction (SPD) is caused by the symphysis joint loosening in preparation for birth, this instability causes strain on surrounding joints. One cause of SPD is excessive weight gain in gestation. SPD is diagnosed from the symptoms that the woman is experiencing which are often moderate to severe pains that interfere with normal movement and activity and a physical exam from the health professional dependent on level of pain. This is untreatable during pregnancy however pain management such as medication, pelvic support belts, heat pads and seating/sleeping positions along with strengthening exercises such as pelvic floor and gentle yoga can be advised. SPD could lead to the mother becoming less active and if there is little to no support around her may affect her diet choices too, it’s important that she is encouraged to keep moving as much as is safe and possible.[13]
Signs of preeclampsia that may be reported are headaches, nausea, noticeable oedema in hands, feet and face and vision changes.[14] Blood pressure (BP) monitoring is required throughout gestation as some women can develop preeclampsia, often after 20 weeks. Diabetes and obesity are linked to a higher risk of developing preeclampsia, and it is diagnosed by high BP, proteins present in urine samples and ultrasounds to monitor foetal growth. Preeclampsia reduces foetal growth by reducing blood flow/nutrients to the placenta.[15]
Dietary
Food Frequency Questionnaires (FFQ) are useful for measuring the nutrient intake for individuals in specific populations by using a preorganised list of foods to estimate consumption.[16] FFQs with modifications to suit pregnancy nutritional needs would be ideal to use with pregnant women as it doesn’t require professional input and can be done in their free time and relatively quickly, compared with other methods such as a food diary. This method relies on memory which may be difficult for women during pregnancy but in a modified FFQ for pregnancy there would be a wide range of food items and nutrients available to assist with this, although some items could be missed due to cultural and health reasons. Another limitation of using this method is that there could be underrepresentation of unhealthy food intakes or portion sizes and if a woman is experiencing morning sickness it would be difficult to know how her body is absorbing the nutrients.[17]
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