Articles
Pregnancy Nutrition
A woman’s nutritional status pre-pregnancy is extremely important, and in many cases overlooked. All women planning a pregnancy should ensure their body is in the optimal condition for the long and hard task ahead. Even if your pregnancy is unplanned, or happens earlier than expected, you can still make sure you give yourself and your baby the nutrients you both need.
Pre-pregnancy Weight
Pre-pregnancy weight, and more importantly pre-pregnancy BMI (body mass index), is a very important predictor of potential adverse outcomes for a pregnancy. Being underweight or overweight can lead to complications for the mother and the fetus. When planning a pregnancy, your current weight should be assessed and weight loss or weight gain may be advised. You should aim to reach a weight that places you in the ‘normal’ category for BMI (20 to 25). This is where a Dietitian can be most helpful.
Nutrient Checklist
It is important that you have adequate levels of some important vitamins and minerals prior to becoming pregnant, as it may be hard to play catch-up once the fetus begins to grow. Taking a pre-pregnancy supplement, or even a pregnancy supplement, before you become pregnant will help to ensure your levels are adequate.
Folate
A woman’s folate status is extremely important before and during a pregnancy. Folate, or folic acid, is required for normal growth and development of the baby and it is proven that adequate folate levels will reduce the risk of the fetus developing neural tube defects. The recommended dietary intake for folate during pregnancy is 600µg/day. This is best achieved by supplementing the diet with a folate supplement. NHMRC recommend women begin taking folate supplements of 400µg/day at least one month before becoming pregnant and three months into the pregnancy. If you are taking a pregnancy multivitamin, check to ensure it contains this amount of folate. If not, you will need to take an additional folate supplement. In addition to supplements, dietary sources should be consumed. Folate can be found in broccoli, spinach and salad greens, some fruits and fortified cereals.
Vitamin D
Vitamin D plays an important role in bone development of the fetus during pregnancy, as it aids in the absorption of calcium. Studies suggest that early postnatal and intrauterine bone development contributes to a person's overall bone mineral accrual later in life. Vitamin D deficiency in the mother during pregnancy can therefore influence the child’s risk of osteoporosis in the future. The best source of Vitamin D is sunshine, so women who cover up or avoid the sun completely should be sure to have their Vitamin D status checked. Dietary sources include egg yolk, certain fish, liver and fortified foods such as some milks. Most pregnancy supplements will contain a small amount of Vitamin D. Further supplementation will only be required upon Doctors orders.
Iodine
Iodine is important for baby’s growth and brain development. The RDI is 220µg/day. The NHMRC recommend this come from a supplement source that contains 150 µg per tablet. Ensure your pregnancy multivitamin contain at least this amount per dose. The remaining iodine should come from the diet. Dietary sources include seafood, iodised salt, bread fortified with iodine, eggs and fortified margarine.
Iron
Iron is used in the formation of all the red blood cells needed by the mother and the baby. It also allows the movement of oxygen in the blood, which is used for the growing fetus and the mother. The RDI during pregnancy is 27mg/day. All good pregnancy multivitamins will contain iron in some amount, and the rest should be obtained through diet. The best dietary sources of iron include lean meat, oysters, green leafy vegetables, legumes and fortified cereals. Iron absorption can vary depending on the person, the type of food consumed and the total meal. To increase iron absorption, eat food high in vitamin C, such as colourful fruits and vegetables, with iron containing foods. Try to avoid caffeine, as this decreases iron absorption.
Weight Gain
The total amount of weight gain during pregnancy is determined by many factors, such as psychological, behavioral, family, social, cultural, and environmental. If weight gain is excessive or insufficient, all of these aspects should be assessed. It is best practice to base expected weight gain on pre-pregnancy BMI, and these figures are outlined in the table below.
Not gaining enough weight during pregnancy may mean the baby will miss out on some important nutrients. It has also been shown that lower maternal weight gain is linked to preterm birth. On the other hand, gaining too much weight can cause problems such as high blood pressure, gestational diabetes, delivery complications, a large birth weight baby, increased risk of unsuccessful breastfeeding and weight retention in the mother post-pregnancy.
Gestational Diabetes
Insulin resistance and glucose intolerance during pregnancy are more common in today’s society, as many women are entering pregnancy overweight or obese, and may already be experiencing these symptoms prior to pregnancy. Weight gain in pregnancy is attributed to increases in fluid, blood volume and the fetus itself, but there is also an increase in the mother’s fat stores. This is normal and is accompanied by a state of relative insulin resistance which tends to start mid-pregnancy. This is an adaptive response to the pregnancy and increases the transfer of energy across the placenta to the growing fetus. In overweight and obese pregnant women, the insulin resistance is far greater and more severe than in normal weight women. These women have a greater risk of developing hyperglycemia (increased glucose in the blood) and gestational diabetes.
If pregnant women have hyperglycemia, the fetus also experiences hyperglycemia. The fetus produces more insulin to try and normalize the levels of glucose for itself and mother. This increased insulin leads to increased fat storage in the fetus, larger birth weight babies and sometimes complications for the baby at birth. These babies have also been shown to be at greater risk of future morbidities such as overweight, obesity, diabetes and heart disease.
Recommendations for Total and Rate of Weight Gain during Pregnancy, by Pre-pregnancy BMI
Underweight (less than 18.5)
Total wght gain = 12.5-18kg
Rate of weight gain in 2nd trimester = 0.51kg per week
Rate of weight gain in 3rd trimester = 1kg per week
Normal(18.5-24.9)
Total wght gain = 11.5-16kg
Rate of weight gain in 2nd trimester = 0.42kg per week
Rate of weight gain in 3rd trimester = 1kg per week
Overweight(25-29.9)
Total wght gain = 7-11.5kg
Rate of weight gain in 2nd trimester = 0.28kg per week
Rate of weight gain in 3rd trimester = 0.6kg per week
Obese (more than 30)
Total wght gain = 5-9kg
Rate of weight gain in 2nd trimester = 0.22kg per week
Rate of weight gain in 3rd trimester = 0.5kg per week
Added to site on : Monday, 28 February 2011