HCG is secreted by?

Appeared in: DHS Staff Nurse - 2018 (Shift-2nd)

Explanation

Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone produced during pregnancy.
It is secreted by the syncytiotrophoblast cells, which are specialized cells in the outer layer of the placenta.
The primary function of hCG is to maintain the corpus luteum in the ovary during the first trimester, ensuring the continued production of progesterone which is vital for sustaining the pregnancy.
Its presence in blood and urine is the basis for pregnancy testing.

Option B: The ovary (specifically the corpus luteum) does not secrete hCG. Instead, it is the target of hCG. HCG stimulates the corpus luteum to continue producing progesterone in early pregnancy.
Option C: The adenohypophysis (anterior pituitary gland) secretes gonadotropins like Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH). While hCG is structurally similar to LH, it is not produced by the pituitary during pregnancy.
Option D: The pars intermedia is a lobe of the pituitary gland that is often rudimentary in humans. Its primary secretion is Melanocyte-Stimulating Hormone (MSH), and it has no role in producing hCG.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormonal physiology of pregnancy as background academic context rather than a clinical decision trigger.
Monitoring serial hCG levels is a fundamental tool for assessing the viability of an early pregnancy. In a normal intrauterine pregnancy, levels should approximately double every 48-72 hours.
A nurse must understand the significance of hCG trends. Slow-rising, plateauing, or falling levels can indicate an ectopic pregnancy or an impending miscarriage, requiring prompt patient education and follow-up.
Extremely high hCG levels for gestational age are a critical warning sign for gestational trophoblastic disease (molar pregnancy) and necessitate further investigation.

How to Approach the Question

This is a factual recall question testing knowledge of reproductive endocrinology.
Identify the key term in the question: 'HCG' (Human Chorionic Gonadotropin). The name itself offers a clue, as 'Chorionic' refers to the chorion, a component of the placenta.
Recall the primary association of HCG: it is widely known as the 'pregnancy hormone'.
Evaluate the options based on this association:
A) Placenta: The primary organ of pregnancy, making it the most logical source.
B) Ovary: Involved in ovulation and early pregnancy maintenance but is acted upon by HCG, rather than producing it.

Concept Tested & Keywords

Q5K6Qve1qTPVMQr4AeWlVA

E6 Gynecology Williams pp. 351-421, 352-421

E6 Obstetrics Williams p. 6

Practise the full DHS Staff Nurse - 2018 (Shift-2nd)

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