Which of the following hormones secreted during pregnancy causes vasodilation and lowers blood pressure?

Appeared in: MP CHO - 2022

Explanation

Progesterone is a steroid hormone that plays a crucial role in maintaining pregnancy.
It has a significant relaxing effect on smooth muscles, including those lining the walls of blood vessels.
This smooth muscle relaxation leads to systemic vasodilation (widening of blood vessels).
Vasodilation decreases the overall resistance in the circulatory system (systemic vascular resistance), causing a drop in maternal blood pressure.
This effect is most pronounced in the first and second trimesters, where blood pressure typically reaches its lowest point (nadir).

Option A: Antidiuretic hormone (ADH), also called vasopressin, is a vasoconstrictor. It narrows blood vessels and promotes water retention by the kidneys, both of which increase blood pressure.
Option B: Angiotensin II is one of the body's most potent vasoconstrictors. It causes blood vessels to narrow, which significantly increases blood pressure.
Option D: This option is incorrect because a correct answer, Progesterone, is listed among the choices.

Clinical Relevance

Nursing practice connection: Knowing Physiological changes during pregnancy, specifically the hormonal regulation of blood pressure helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
The progesterone-induced drop in blood pressure is a normal physiological adaptation in pregnancy to accommodate increased blood volume.
This vasodilation can make pregnant women prone to dizziness, lightheadedness, and fainting, particularly with sudden changes in position (postural hypotension).
Nurses should educate pregnant clients to rise slowly from a sitting or lying position to prevent symptoms of postural hypotension.

How to Approach the Question

First, identify the key concepts in the question: a hormone secreted during pregnancy that causes vasodilation and lowers blood pressure.
Recall the major hormones of pregnancy and their primary functions.
Evaluate each option:
Antidiuretic hormone (ADH): Recall its role in water balance and vasoconstriction (raises BP).
Angiotensin: Recall its role as a potent vasoconstrictor (raises BP).
Progesterone: Recall its role as a smooth muscle relaxant.

Concept Tested & Keywords

Concept Tested: Physiological changes during pregnancy, specifically the hormonal regulation of blood pressure.
Stem keywords: hormones, pregnancy, vasodilation, lowers blood pressure
Lead-in keywords: Which

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Practise the full MP CHO - 2022

Attempt every question from this paper in a timed mock, then review the full solution for each one.