Placenta secretes all the following hormones, EXCEPT?

Appeared in: AIIMS Bhopal NO - 2018 (Shift-1st)

Explanation

Luteinizing hormone (LH) is the correct answer because it is secreted by the anterior pituitary gland, not the placenta.
The primary function of LH in the female reproductive cycle is to trigger ovulation and stimulate the corpus luteum.
During pregnancy, high levels of estrogen and progesterone produced by the placenta provide negative feedback to the pituitary gland, causing the secretion of LH to be almost completely suppressed.

Option A: This is incorrect because Human chorionic gonadotropin (hCG) is one of the first and most important hormones secreted by the syncytiotrophoblast cells of the placenta after implantation.
Option C: This is incorrect because the placenta becomes the main source of oestrogen production as pregnancy progresses, taking over from the ovaries.
Option D: This is incorrect because after the first trimester, the placenta is the primary producer of progesterone, which is essential for maintaining the uterine lining and preventing premature labor.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Endocrine function of the placenta as background academic context rather than a clinical decision trigger.
Understanding the origin of pregnancy hormones is fundamental for nurses in interpreting diagnostic tests. For instance, hCG is the hormone detected in urine and blood pregnancy tests.
Monitoring levels of placental hormones can help identify potential pregnancy complications. Extremely high hCG levels may suggest a molar pregnancy, while low progesterone could indicate a risk of miscarriage.
Patient education about these hormones helps explain the physiological changes of pregnancy and the rationale behind certain medical interventions.

How to Approach the Question

First, identify the keyword 'EXCEPT' in the question. This signals that you must find the option that does not belong with the others.
The question's subject is hormones secreted by the placenta.
Recall the major hormones associated with pregnancy and their sources.
Evaluate each option: Human chorionic gonadotropin (hCG) is the classic placental hormone. Oestrogen and progesterone are also produced in large quantities by the placenta.
Consider Luteinizing hormone (LH). Remember that LH is a pituitary hormone responsible for triggering ovulation. Since ovulation stops during pregnancy, it makes sense that this hormone would not be produced by the placenta and would be suppressed.
Conclude that Luteinizing hormone is the correct exception.

Concept Tested & Keywords

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E6 Physiology Essentials Sembulingam 10e Part 2 p. 145-147

E6 Physiology Guyton 4SAE Part 3 p. 60-62

Practise the full AIIMS Bhopal NO - 2018 (Shift-1st)

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