The maternity nurse understands that vascular volume increases 40% to 45% during pregnancy to:

Choice A reason: Intranasal spray is not a correct option, as urofollitropin is not available in this form. Intranasal spray is a method of delivering some medications through the nose, where they can be absorbed by the mucous membranes. However, urofollitropin is a protein hormone that would be degraded by the enzymes in the nasal cavity and would not reach the bloodstream effectively.

Choice B reason: Intramuscular injection is the correct option, as urofollitropin is available in this form. Intramuscular injection is a method of delivering medications into the muscle tissue, where they can be absorbed by the blood vessels. Urofollitropin is a protein hormone that needs to be injected into the body to bypass the digestive system and avoid being broken down by the stomach acids and enzymes. Urofollitropin is usually injected into the thigh or buttock muscles once a day for several days, depending on the dosage and the response².

Choice C reason: Vaginal suppository is not a correct option, as urofollitropin is not available in this form. Vaginal suppository is a method of delivering medications into the vagina, where they can be absorbed by the vaginal walls or act locally. Urofollitropin is a protein hormone that would not be absorbed well by the vaginal mucosa and would not reach the ovaries, where it is supposed to stimulate the development of the follicles (eggs).

Choice D reason: Tablet is not a correct option, as urofollitropin is not available in this form. Tablet is a method of delivering medications orally, where they can be swallowed and absorbed by the gastrointestinal tract. Urofollitropin is a protein hormone that would be destroyed by the stomach acids and enzymes and would not reach the bloodstream or the ovaries.

Choice A reason: Vascular volume increases during pregnancy to meet the increased oxygen and nutrient demands of the fetus, not to compensate for decreased renal plasma flow. In fact, renal plasma flow increases by 50% to 80% during pregnancy to facilitate the excretion of metabolic wastes.

Choice B reason: Vascular volume increases during pregnancy to ensure adequate blood supply to the uterus and other organs, not to prevent maternal and fetal dehydration. Dehydration can occur due to vomiting, diarrhea, or inadequate fluid intake, and it can be prevented by drinking enough fluids and replacing electrolytes.

Choice C reason: Vascular volume increases during pregnancy to provide adequate perfusion of the placenta, which is the main organ of gas exchange and nutrient delivery for the fetus. The placenta receives about 10% of the maternal cardiac output at term.

Choice D reason: Vascular volume increases during pregnancy to support the growth and development of the fetus and the maternal tissues, not to eliminate metabolic wastes of the mother. Metabolic wastes are eliminated by the kidneys, lungs, skin, and gastrointestinal tract.