The nurse caring for the pregnant client must understand that the hormone essential for maintaining pregnancy is:

Choice A rationale

Heartburn, or pyrosis, is often caused by the relaxation of the lower esophageal sphincter (LES) due to pregnancy hormones like progesterone and the upward pressure from the enlarging uterus. Substituting other calcium sources for milk is not a primary intervention because milk, while sometimes a temporary buffer, does not address the underlying mechanical and hormonal causes of acid reflux.

Choice B rationale

Fiber-rich foods promote bowel regularity and are essential during pregnancy to prevent constipation, a common discomfort. Reducing fiber is an inappropriate suggestion for managing heartburn; instead, the focus should be on dietary modifications that lessen gastric reflux, such as avoiding spicy or acidic foods.

Choice C rationale

Eating five small meals daily prevents the stomach from becoming overly distended, which is a key contributor to pushing stomach contents, including acid, back up into the esophagus through the relaxed LES. Smaller, more frequent meals, along with maintaining an upright posture after eating, are effective non-pharmacological methods to manage reflux discomfort.

Choice D rationale

Lying down after meals is strongly discouraged for individuals experiencing heartburn, particularly in late pregnancy. The recumbent position allows gravity to assist the reflux of stomach acid into the esophagus, which will intensify the burning sensation. The woman should remain upright for at least two to three hours following food consumption.

Choice A rationale

While adequate hydration is absolutely crucial during pregnancy, especially with exercise, focusing solely on "several glasses of fluid" is incomplete. The most critical nutrient to replace during aerobic exercise, like tennis, is readily available glucose from carbohydrates to prevent maternal hypoglycemia, which can harm the fetus and trigger ketosis. Fluids are vital but D addresses the immediate energy need.

Choice B rationale

Replacing sodium via salty foods is generally not necessary during moderate exercise and normal fluid intake. Excessive sodium could exacerbate dependent edema, which is common in late pregnancy, and potentially increase blood pressure in a susceptible woman. Plain water or sports drinks with small amounts of electrolytes are preferred for fluid balance.

Choice C rationale

Protein is essential for tissue growth and repair, but it is not the immediate energy source needed to fuel the high energy demands of exercise. The body relies primarily on stored glycogen and circulating glucose (carbohydrates) during physical activity; utilizing protein for energy, known as gluconeogenesis, is an inefficient and less desirable process.

Choice D rationale

Easily digested sources of carbohydrate, such as fruit or energy bars, are the most important nutritional intake before and during exercise. The metabolic demands of the fetus and physical activity increase the mother's need for glucose; consuming carbohydrates prevents maternal hypoglycemia and subsequent ketosis, which is a harmful metabolic state for the fetus.