Infants Case

Infants who are born on time but have failed to grow well in the uterus are said to

be small-for-gestational-age. Those born before 37 weeks of gestation are said to be

preterm or premature. Whether born too soon or just too small, low-birth-weight infants

and very-low-birth-weight infants are at increased risk for illness and early

death.2 They often require special care and a special diet in order to successfully continue

to grow and develop. Survival improves with increasing gestational age and birth

weight. Today, with advances in medical and nutritional care, infants born as early as

25 weeks of gestation and those weighing as little as 1 kg (2.2 pounds) can survive.

During pregnancy, a woman's body must undergo many changes to support the development

of her child. Her blood volume increases by 50%, and her heart, lungs, and

kidneys work harder to deliver nutrients and oxygen and remove wastes. The placenta

develops to allow nutrients to be delivered to the growing fetus and the hormones it

produces orchestrate other changes. Body fat increases to provide the energy needed

late in pregnancy, the uterus enlarges, muscles and ligaments relax to accommodate

the growing fetus and allow for childbirth, and the breasts develop to prepare for lactation.

These changes all result in weight gain and can affect the type and level of physical

activity that is safe. In some cases they can also cause uncomfortable side effects