During which week does the fetal heart begin pumping its own blood?

Appeared in: GMCH Chandigarh - 2019

Explanation

The fetal heart begins to beat and establish a true circulatory system during the 4th week of embryonic development, around day 22-23 after fertilization.
This is the point when the fused primitive heart tube starts coordinated contractions to actively pump blood throughout the embryo.
Textbook sources confirm that a true circulation is established during the fourth week of gestation (SRC_5182).

Option A: During the 3rd week, the primitive heart tubes are forming and beginning to fuse. Established, effective pumping of blood does not occur until the 4th week.
Option C: By the 5th week, the heart is already pumping blood and is undergoing further complex development, including the partitioning of its chambers.
Option D: By the 6th week, cardiac activity is well-established and can typically be detected by transvaginal ultrasound. The heart began pumping blood two weeks earlier.

Clinical Relevance

Nursing practice connection: Knowing Timeline of fetal cardiac development helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding this timeline is fundamental for interpreting early pregnancy ultrasounds and assessing fetal viability.
The detection of cardiac activity, typically visible via transvaginal ultrasound from 5-6 weeks of gestation, is often the first definitive sign of a viable intrauterine pregnancy.
Knowledge of these milestones helps nurses educate expectant parents about fetal development and the significance of early ultrasound findings.

How to Approach the Question

This is a factual recall question about a key milestone in embryology.
First, identify the core concept being tested: the initiation of fetal heart function (pumping blood).
Recall the general sequence of early embryonic development: formation of structures precedes their function.
Associate the 3rd week with the formation of the primitive heart tubes.
Associate the 4th week with the beginning of function for the cardiovascular system, which includes the first effective heartbeats and establishment of circulation.
Eliminate later weeks (5th and 6th) as they represent more advanced stages of development, not the initial start of pumping.

Concept Tested & Keywords

QJBqRlEowIWFFwPjNwyOcI

E6 Obstetrics Williams pp. 19-36, 21-40

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 188-190

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