In a pregnant woman during the 2nd trimester, which cardiovascular finding is considered normal physiological… - NORCET 10 Mains

NORCET 10 Mains

Obstetrics & Gynaecology

Easy

Appeared in: NORCET 10 Mains

Explanation

The maternal heart rate progressively increases throughout pregnancy, typically by 10 to 20 beats per minute over the non-pregnant baseline.
This tachycardia is a necessary adaptation to the significant increase in blood volume (by 40-50%) and cardiac output (by 30-50%).
The increased heart rate helps maintain adequate blood flow and oxygen delivery to the growing fetus, placenta, and maternal organs.
This change begins in the first trimester and is well-established by the second trimester.

Option A: While a decrease in blood pressure is a normal and expected finding, the increase in heart rate is a more direct and sustained compensatory mechanism to the increased circulatory volume throughout pregnancy. The drop in blood pressure is a net result of vasodilation being greater than the rise in cardiac output.
Option B: An increase in blood pressure above baseline is not a normal physiological change during the second trimester.
Option D: A decrease in heart rate (bradycardia) is not a normal adaptation to pregnancy.

Visual 1: Chart - A line graph showing the typical trends of heart rate, blood pressure, cardiac output, and systemic vascular resistance across the three trimesters of pregnancy. This helps visualize the nadir of BP in the second trimester and the steady rise of HR.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiological cardiovascular changes during pregnancy as background academic context rather than a clinical decision trigger.
Monitoring blood pressure and heart rate at every prenatal visit is crucial to track these normal physiological adaptations and to screen for the development of hypertensive disorders like preeclampsia.
Nurses should educate pregnant women about symptoms of orthostatic hypotension (dizziness upon standing), which can occur due to the physiological drop in blood pressure, and advise them to change positions slowly.
What if? A woman in her second trimester, who previously had normal blood pressure, presents with a BP of 145/95 mmHg. This is no longer a normal physiological change. It is a significant increase that warrants immediate investigation for preeclampsia, including checking for proteinuria and other signs of end-organ damage.

How to Approach the Question

This is a factual recall question testing knowledge of physiological changes during pregnancy.
First, recall the major cardiovascular adaptations that occur to support the pregnancy: blood volume increases, cardiac output increases, heart rate increases, and systemic vascular resistance decreases.
Next, consider the typical timeline for these changes. The heart rate increases steadily throughout pregnancy.
Remember the specific pattern of blood pressure: it falls during the first and second trimesters, reaching its lowest point (nadir) mid-pregnancy, before rising back towards pre-pregnancy levels in the third trimester.
Evaluate each option against these facts. Both 'Decreased blood pressure' and 'Increased heart rate' are normal findings in the second trimester.
Recognize that this may be a 'best answer' question. While both are correct phenomena, the increased heart rate is a consistent, primary adaptation that occurs throughout pregnancy to manage the increased circulatory load.

Concept Tested & Keywords

Concept Tested: Physiological cardiovascular changes during pregnancy.
Stem keywords: pregnant woman, 2nd trimester, cardiovascular finding, normal physiological change
Lead-in keywords: which
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.
Negative lead-in flag: false

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