Human chorionic gonadotropin is produced by?

AIIMS Bhuvneshwar NO- 2018

Obstetrics & Gynaecology

Easy

Appeared in: AIIMS Bhuvneshwar NO- 2018

Explanation

Human chorionic gonadotropin (hCG) is a hormone produced by the syncytiotrophoblast cells of the placenta shortly after implantation.
The primary role of hCG is to maintain the corpus luteum, which in turn continues to secrete progesterone, a hormone critical for maintaining the pregnancy.
hCG levels rise rapidly in early pregnancy, making it the key marker detected in both urine and serum pregnancy tests.

Option B: The decidua is the modified lining of the uterus (endometrium) during pregnancy. It is maternal tissue and does not produce hCG.
Option C: The yolk sac is an extraembryonic membrane that provides nourishment and is the site of early blood cell formation. It produces alpha-fetoprotein (AFP), not hCG.
Option D: The cytotrophoblast is the inner layer of the trophoblast. These cells are precursors that proliferate and differentiate to form the syncytiotrophoblast. They do not secrete significant amounts of hCG themselves.

Visual 1: Diagram: Illustration of the early placenta showing the relationship between the inner cytotrophoblast and the outer syncytiotrophoblast layer, highlighting the syncytiotrophoblast as the site of hCG production.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Source of Human Chorionic Gonadotropin (hCG) production as background academic context rather than a clinical decision trigger.
Understanding the source and timing of hCG production is fundamental for nurses interpreting pregnancy tests and counseling patients on early pregnancy signs.
Abnormally low, high, or slowly rising hCG levels can indicate potential complications like ectopic pregnancy, molar pregnancy, or miscarriage, requiring prompt nursing assessment and physician referral.
What if? If a patient's hCG levels double every 7 days instead of every 48-72 hours in early pregnancy, the nurse should suspect a non-viable pregnancy (e.g., ectopic or impending miscarriage) and facilitate further diagnostic evaluation.

How to Approach the Question

First, identify the core of the question: it's asking for the specific cell type that produces the hormone hCG.
This is a factual recall question from reproductive physiology or obstetrics.
Mentally review the structures of early pregnancy: the embryo, placenta, and maternal uterus.
Recall that the placenta is the primary hormone-producing organ of pregnancy. Differentiate between its layers (cytotrophoblast and syncytiotrophoblast) and their functions.
Eliminate options that are clearly incorrect: the decidua is maternal tissue, and the yolk sac has other primary functions.
Between the two trophoblast layers, remember that the syncytiotrophoblast is the outer, active, hormone-secreting layer.

Concept Tested & Keywords

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