Chapter Summary for Nutrition: Concepts and Controversies 11e
Chapter 13 – Life Cycle Nutrition: Mother and Infant
Adequate nutrition before pregnancy establishes physical readiness and nutrient stores to support fetal growth. Both underweight and overweight women should strive for appropriate body weights before pregnancy. Newborns who weigh less than 5 ½ pounds face greater health risks than normal-weight babies. The healthy development of the placenta depends on adequate nutrition before pregnancy. Implantation, fetal development, and early critical periods depend on maternal nutrition before and during pregnancy. Pregnancy brings physiological adjustments that demand increased intakes of energy and nutrients. A balanced diet that includes more nutrient-dense foods from the five food groups can help to meet these needs. Due to their key roles in cell reproduction, folate and vitamin B12 are needed in large amounts during pregnancy. Folate plays an important role in preventing neural tube defects. All pregnant women, but especially those who are less than 25 years of age, need to pay special attention to ensure adequate calcium intakes. A daily iron supplement is recommended for all pregnant women during the second and third trimesters. Women most likely to benefit from multivitamin-mineral supplements during pregnancy include those who do not eat adequately, those carrying twins or triplets, and those who smoke cigarettes or are alcohol or drug abusers. Food assistance programs such as WIC can provide nutritious food for pregnant women of limited financial means. Weight gain is essential for a healthy pregnancy. A woman’s prepregnancy BMI, her own nutrient needs, and the number of fetuses she is carrying help to determine appropriate weight gain. Physically fit women can continue to be physically active throughout pregnancy. Pregnant women should be cautious in their choice of activities. Of all the population groups, pregnant teenage girls have the highest nutrient needs and an increased likelihood of having problem pregnancies. Food cravings usually do not reflect physiological needs, and some may interfere with nutrition. Nausea arises from normal hormonal changes of pregnancy. Abstaining from smoking and other drugs, limiting intake of foods known to contain unsafe levels of contaminants such as mercury, taking precautions against foodborne illness, avoiding large doses of nutrients, refraining from dieting, using artificial sweeteners in moderation, and limiting caffeine use are recommended during pregnancy.
Alcohol limits oxygen delivery to the fetus, slows cell division, and reduces the number of cells organs produce. Alcoholic beverages must bear warnings to pregnant women. The birth defects of fetal alcohol syndrome arise from severe damage to the fetus caused by alcohol. Lesser conditions, ARND and ARBD, may be harder to diagnose but also rob the child of a normal life. Abstinence from alcohol is critical to prevent irreversible damage to the fetus.
Gestational diabetes and preeclampsia are common medical problems associated with pregnancy. These should be managed to minimize associated risks.
The lactating woman needs extra fluid and enough energy and nutrients to make sufficient milk each day. Malnutrition most often diminishes the quantity of the milk produced without altering quality. Lactation may facilitate loss of the extra fat gained during pregnancy. Breastfeeding is not advised if the mother’s milk is contaminated with alcohol, drugs, or environmental pollutants. Most ordinary infections such as colds have no effect on breastfeeding. Where safe alternatives are available, HIV-infected women should not breastfeed their infants. Infants’ rapid growth and development depend on adequate nutrient supplies, including water from breast milk or formula. Breast milk is the ideal food for infants because it provides the needed nutrients in the right proportions and protective factors as well. Infant formulas are designed to resemble breast milk and must meet an AAP standard for nutrient composition. Special formulas are available for premature infants, allergic infants, and others. Formula should be replaced with milk only after the baby’s first birthday. Solid food additions to an infant’s diet should begin at about 6 months and should be governed by the infant’s nutrient needs and readiness to eat. By 1 year, the baby should be receiving foods from all food groups. The early feeding of the infant lays the foundation for lifelong eating habits. It is desirable to foster preferences that will support normal development and health throughout life.