Chapter 15: Maternal Nutrition

Folate and Folic Acid

Because of the increase in RBC production during pregnancy, as well as the nutritional requirements of the rapidly growing cells in the fetus and placenta, pregnant women should consume about 50% more folic acid than non-pregnant women, or about 0.6 mg daily

Longitudinal assessment of weight gain during pregnancy

Best way to determine whether kcal intake is adequate

Commonly used method of evaluating appropriateness of weight for height (Primary factor to consider in making a weight gain recommendation) is:

Body mass index (BMI) BMI = Weight / Height^2

Protein also source of

Calcium Iron B vitamins

Suggested: Taking micronutrient supplement (including vitamins and trace minerals) before and during pregnancy reduces risk for:

Congenital defects LBW Preterm birth Preeclampsia

Excessive amounts of preformed vitamin A (from supplements)

Congenital malformations during pregnancy (Spina bifida and cleft palate) (Extra supplements in addition to commonly prescribed prenatal vitamins are not recommended routinely for pregnant women)

Zinc

Constituent of numerous enzymes involved in major metabolic pathways. Recommended intake for pregnant women: 11 mg/day Women with anemia who receive high dose iron supplements also need supplements of zinc and copper.

Plant sources of protein often provide needed:

Dietary fiber

Potassium

Diets including adequate intakes of potassium are associated with reduced risk for hypertension. One of the most nutrients most likely to be lacking in the diets of women in childbearing years.

Plasma volume increases more than RBC mass

Difference between plasma and RBCs being greatest during second trimester

Natural almond milk

Does not contain adequate calcium Lower in protein than cow's milk

Use of vitamin-mineral supplement

Does not lessen need to consume a nutritious, well-balanced diet.

Adequate sodium intake (Pregnant, lactating women, and non-pregnant women in childbearing years):

1.5 g/day, with recommended upper limit of intake of 2.3 g/day

Recommended iron intake for pregnant women:

27 mg/day (Non-pregnant: 18 mg/day)

Calcium supplements

600mg needed if: Calcium intake is low & women does not change dietary habits & Pregnant women who experiences leg cramps caused by imbalance in calcium-to-phosphorus ratio

Daily protein intake during pregnancy:

71 g/day (An increase of 25 g/day over non-pregnant level)

Adequate amounts of potassium and reduction of sodium intake includes:

8-10 servings of unprocessed fruits and vegetables daily Moderate amounts of low-fat meats and dairy products

Fat-Soluble Vitamins

A,D,E,K Stored in body tissues (In the event of prolonged overdoses, these vitamins can reach toxic levels) Because of high potential for toxicity, pregnant women are advised to take fat-soluble vitamin supplements only as prescribed.

Vitamin D

Absorption and metabolism of calcium Main food sources: Enriched or fortified foods such as milk and ready-to-eat cereals Also produced in the skin by action of ultraviolet light (sunlight)

Iron is needed to:

Allow transfer of adequate iron to the fetus and to permit expansion of the maternal red blood cell (RBC) mass.

Vitamin A

Allows sufficient amounts of vitamin to be stored in the fetus Diet: Deep yellow and dark green vegetables (leafy greens, broccoli, carrots) Fruits (cantaloupe and apricots) Well chosen diet provides sufficient amounts of carotenes that can be converted in the body to vitamin A.

Sodium

During pregnancy, need for sodium increases slightly, primarily because body water is expanding (expanding blood volume). Essential for maintaining body water balance. Moderate peripheral edema is normal (occurs as response to fluid-retaining effects of elevated levels of estrogen). Restriction has not proved effective in reducing preeclampsia Severe sodium restriction can make it difficult for pregnant women to achieve an adequate diet. Significant sources of sodium: Grain Milk Meat products

Vitamin B6 (Pyridoxine)

Essential for carbohydrate, protein, and fat metabolism. Involved in the synthesis of red blood cells, antibodies, and neurotransmitters

During third trimester growth occurs primarily in:

Fetal tissues

Pregnant women need to gain at least enough weight to equal the weight of the products of conception

Fetus Placenta Amniotic fluid

Water-Soluble Vitamins

Folate and Folic Acid Vitamin's: C, B6, B12 Body stores of water-soluble vitamins are much smaller than those of fat-soluble vitamins Readily excreted in the urine Must be consumed frequently Toxicity with overdose is less likely than it is when taking fat-soluble vitamins

Cannot be met through dietary resources:

Folate and iron

Both normal-weight and underweight women with inadequate weight gain during pregnancy have an increased risk of

Giving birth to an infant with intrauterine growth restriction (IUGR)

Lactation

Helps reduce maternal energy stores gradually Provides an opportunity to promote breastfeeding.

Excessive weight gained during pregnancy can be difficult to lose after pregnancy, thus contributing to chronic overweight or obesity - an etiologic factor in a host of chronic diseases such as:

Hypertension Diabetes mellitus Arteriosclerotic heart disease (Especially those who gains 18kg or more )

Excessive intake of sodium leads to

Hypertension in salt-sensitive individuals

Vitamin C (Ascorbic Acid)

Important in tissue formation and enhances iron absorption Recommended intake of vitamin C during pregnancy is 85mg/day Needs are readily met by diet that includes at least: One or two daily servings of citrus fruit or juice or another good source of vitamin Women who smoke needs more vitamin C intake

Lactose intolerance

Inability to digest milk sugar (lactose) caused by the lack of the lactase enzyme in the small intestine. Common: African-Americans Asians Native Americans Inuits (Alaska Natives) Causes: Abdominal cramping Bloating Diarrhea

Women are at increased risk for iron deficiency during pregnancy related to:

Increased iron requirements

Dehydration

Increases risk of cramping, contractions, and preterm labor

Poor iron status

Iron deficiency anemia Poorly prepared to tolerate hemorrhage at time of birth Increased risk for preterm birth (Iron deficiency during third trimester does not carry same risk)

Risk for vitamin D deficiency

Lactose intolerant women Vegan diets Those who do not include milk in their diet Dark skin (African-American @ highest risk) Habitual use of clothing that covers most of the skin Living in northern latitudes where sunlight exposure is limited, especially during winter

Zinc is inhibited when:

Large amounts of iron and folic acid are consumed. Serum zinc levels are reduced as a result

Essential to brain development and neurologic function

Long-chain polyunsaturated fatty acids (LC-PUFAs) docosahexaenoic acid (DHA) and arachidonic acid (AA)

Magnesium

Low in childbearing years of women Lactating women may have inadequate intakes (Adolescents and low-income women are especially at risk) Recommended daily intake during pregnancy: 400 mg Dairy products Nuts Whole grains Green leafy vegetables

Calcium

MILK AND YOGURT No increase in DRI of calcium during pregnancy and lactation DRI appears to provide sufficient calcium for fetal bone and tooth development while maintaining maternal bone mass (1000mg daily for women 19 years and older 1300mg daily for those younger than 19 years)

Water

Main substance of cells, blood, lymph, amniotic fluid, and other vital body fluids Essential during exchange of nutrients and waste products across cell membranes. Aids in maintaining body temperature. Good fluid intake promotes regular bowel function Intake: 8 to 10 glasses (2.3L) of fluid. Water, milk, and decaffeinated or herbal tea are good sources.

Zinc deficiency is associated with:

Malformations of the central nervous system in infants

During first and second trimester growth takes place primarily in:

Maternal Tissues

Complete proteins with high biologic value

Milk Meat Eggs Yogurt Cheese Legumes Whole grains Nuts

Anemia in United States

Most common among: Adolescents African-American women Women of lower socioeconomic status

Greater than expected weight gain during pregnancy causes:

Multiple gestation Edema Gestational hypertension Overeating

Severe deficiency of vitamin D

Neonatal hypocalcemia and tetany Poor development of tooth enamel

Proper closure of neural tube is required for normal formation of spinal cord,

Neural tube begins to close within first month of gestation.

kcal

No increment for first trimester Additional 340 kcal per day and 462 kcal per day over prepregnant intake is recommended during second and third trimester 340 additional kcal need during second trimester can be provided by two additional servings from any of the following groups: Dairy (all low fat or fat free) Fruits Vegetables Grains In third trimester an additional half a serving will provide needed kcal

Key components of Nutritional care during preconception period and pregnancy:

Nutrition Assessment Diagnosis of nutrition-related problems Interventions Evaluation

Folate or folic acid intake 0.4mg folic acid - Capable of becoming pregnant 0.6mg folic acid - During pregnancy 4.0-mg folic acid - Previous pregnancy w/ NTD

Particular concern in periconception period Folate is form in which this vitamin is found naturally in foods, Folic acid is the form used to fortify grain products and other foods and vitamin supplements Neural Tube defects (NTDs), or failures in closure of neural tube are more common in infants of women with poor folic acid intake.

High-protein supplements not recommended

Potential harmful effects on the fetus

Obesity (either preexisting obesity or obesity that develops during pregnancy), increased likelihood of:

Preeclampsia Gestational diabetes Macrosomia Cephalopelvic disproportion Operative Vaginal birth Emergency cesarean birth Postpartum hemorrhage Wound, genital tract, or urinary tract infection Birth trauma Late fetal death

Oxidative stress above that usually associated with pregnancy has been proposed as an explanation for the etiology of:

Preeclampsia (although supplementation with vitamin E has not been shown to prevent preeclampsia)

Iron supplements

Prenatal vitamins (contains 30 mg of iron) Poorly tolerated during nausea in first trimester, starting supplement after may improve tolerance

Low serum vitamin D levels

Prescribed vitamin D supplements of 1000 to 2000 IU/day

Ketonuria associated with:

Preterm labor

Underweight

Preterm labor LBW infants

Products low in nutritive value and excessively high in sodium

Pretzels Potato and other chips (Except salt free), Pickles Catsup Prepared mustard Steak Worcestershire sauces Some soft drinks Bouillon

Vitamin E

Protect against increased oxidative stress associated with pregnancy. Good sources: Vegetable oils and nuts Moderate sources: Whole grains and green leafy vegetables

Protein

Provide amino acids for synthesis for new tissues

Uncommon for adults to drink milk

Puerto Ricans Other hispanics

Adequate protein is needed for tissue growth during pregnancy that results from:

Rapid growth of fetus Enlargement of uterus and its supporting structures, the mammary glands, and placenta The increase in maternal circulating blood volume & subsequent demand for increased amounts of plasma protein to maintain colloidal osmotic pressure Formation of amniotic fluid

DHA supplementation

Recommend: at least 300 mg/day for pregnant women Lack of conclusive evidence on specific beneficial effects of DHA supplementation Some prenatal vitamins contain DHA; fish oil supplements another source of DHA Seafood (Risk of fetal neurotoxicity methylmecury, pregnant women are cautioned to select fish species known to have lower levels of methylmercury)

Supplementation of omega-3 (n-3) LC-PUFA during pregnancy has been associated with

Reduced risk of preterm birth and improved neurologic and visual development in the offspring

Physiologic anemia of pregnancy (normal adaptation during pregnancy)

Relative excess of plasma causes a modest decrease in hemoglobin concentration and hematocrit

Dietary restriction

Results in catabolism of fat stores, which in turn augments production of ketones

Table salt (Sodium chloride)

Richest source of sodium, with approximately 2.3g of sodium in 1 teaspoon (5) of salt. Large amount of sodium food in processed foods (smoked or cured meats, cold cuts, and corned beef; frozen entrees and meals; baked goods; mixes for casseroles or bread products; soups; and condiment.

Maternal obesity also associated with

Risk of miscarriage Congenital anomalies Growth abnormalities Stillbirth Infant likely to be obese and develop diabetes as an adult

Moderate sodium intake can be achieved by:

Salting food lightly during cooking Adding no additional salt at the table Avoiding low-nutrient, high-sodium foods

12 weeks of gestation

Supplement of 30mg of ferrous iron daily Helps ensure an adequate iron intake

Recommended protein for pregnant women

Three serves of milk, yogurt, or cheest Two servings of meat, poultry, or fish

Prepregnant BMI

Underweight or low BMI: Less than 18.5 Normal BMI: 18.5 to 24.9 Overweight or high BMI: 25 - 29

Reduction of vitamin D production by as much as 99%

Use of recommended amounts of sunscreen with a sun protection factor (SPF) rating of 15 or greater This leads to bringing about a need for regular intake of fortified foods or a supplement.

Additional protein is provided by:

Vegetable and breads Cereals rice Pasta

Sodium restriction

can stress adrenal glands and the kidneys as they attempt to retain adequate sodium. Only necessary if woman has medical condition (renal or liver failure or hypertension that warrants it)