Exposure to which prenatal factor during pregnancy is most likely to result in fetal growth restriction?

NCL (Northern Coalfields Limited)-NO

Obstetrics & Gynaecology

Easy

Appeared in: NCL (Northern Coalfields Limited)-NO

Explanation

Maternal smoking is a leading preventable cause of fetal growth restriction (FGR) and low birth weight.
Nicotine, a primary component of tobacco, is a potent vasoconstrictor that reduces blood flow through the uterine and placental vessels, thereby limiting nutrient and oxygen supply to the fetus.
Carbon monoxide in cigarette smoke binds to hemoglobin with high affinity, reducing the oxygen-carrying capacity of maternal blood and causing chronic fetal hypoxia.
The combined effects of vasoconstriction and hypoxia directly impair fetal growth, with smoking raising the risk of FGR two- to threefold.
Even exposure to secondhand smoke has been shown to increase the risk for low birthweight.

Option A: Moderate maternal exercise is considered beneficial and is recommended during a healthy pregnancy. It improves circulation and overall maternal health.
Option B: Maternal folic acid supplementation is a critical intervention to prevent neural tube defects and support healthy cell growth and DNA synthesis in the fetus. It is protective, not harmful.
Option D: Maternal sunlight exposure is the primary source of Vitamin D, which is essential for calcium metabolism and bone health in both the mother and fetus. It is not associated with FGR.

Visual 1: Diagram - An infographic illustrating the pathway of harmful chemicals from a cigarette through the mother's bloodstream to the placenta, highlighting the constriction of uterine arteries and reduced oxygen/nutrient transfer to the fetus.
Visual 2: Comparison Chart - A chart comparing the average birth weight of infants born to smoking mothers versus non-smoking mothers, visually representing the typical 200g weight difference.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Risk factors for Fetal Growth Restriction (FGR) as background academic context rather than a clinical decision trigger.
Nurses have a crucial responsibility to screen all pregnant women for tobacco use, including e-cigarettes and secondhand smoke exposure, at the very first prenatal visit and throughout the pregnancy.
Providing clear, non-judgmental education on the specific risks of smoking (FGR, preterm birth, placental abruption, SIDS) and offering resources for cessation (e.g., quitlines, counseling) is a key nursing intervention.
Monitoring fetal growth via fundal height measurements and ultrasound is essential in pregnant women who smoke to allow for early detection of FGR.

How to Approach the Question

First, identify the core concept of the question, which is identifying a major risk factor for 'fetal growth restriction' (FGR).
The question asks for the 'most likely' factor, implying you should choose the option with the strongest and most direct causal link.
Evaluate each option based on standard prenatal care knowledge.
Option A (exercise) and D (sunlight exposure) are generally considered healthy in moderation during pregnancy.
Option B (folic acid) is a recommended supplement to prevent birth defects, making it an unlikely cause of a growth problem.
Option C (smoking) is widely known to have numerous negative effects on pregnancy due to its chemical components.

Concept Tested & Keywords

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