Pregnancy test is based on estimation of hormone named?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2021

Obstetrics & Gynaecology

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2021

Explanation

Pregnancy tests work by detecting the presence of Human Chorionic Gonadotropin (hCG), which is known as the 'pregnancy hormone'.
hCG is produced by the syncytiotrophoblast cells of the placenta, beginning shortly after the fertilized egg implants into the uterine wall.
The primary function of hCG in early pregnancy is to 'rescue' the corpus luteum, signaling it to continue producing progesterone, which is essential for maintaining the uterine lining and sustaining the pregnancy.
hCG levels rise rapidly and predictably in early pregnancy, typically doubling every 48-72 hours, making it a reliable marker for detection in both urine and blood tests.

Option A: Follicle-Stimulating Hormone (FSH) is primarily involved in stimulating the growth and maturation of ovarian follicles at the beginning of the menstrual cycle, not in signaling or maintaining pregnancy.
Option B: While progesterone is vital for preparing the endometrium and sustaining a pregnancy, it is not the hormone measured in standard pregnancy tests. Its levels can fluctuate and are not as specific for pregnancy detection as hCG.
Option D: Luteinizing Hormone (LH) surge triggers ovulation. Although it shares a common alpha-subunit with hCG, pregnancy tests are designed to be highly specific for the unique beta-subunit of hCG to avoid false positives.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The hormonal basis of pregnancy detection as background academic context rather than a clinical decision trigger.
Quantitative serum hCG testing is a cornerstone of early pregnancy management. Serial measurements help assess the viability of a pregnancy.
A slower-than-expected rise in hCG levels can be an early indicator of a non-viable intrauterine pregnancy or an ectopic pregnancy, prompting further investigation.
Unusually high hCG levels for gestational age may suggest a multiple gestation (e.g., twins) or a molar pregnancy (gestational trophoblastic disease), which requires specific management.

How to Approach the Question

This is a factual recall question testing knowledge of reproductive endocrinology.
First, identify the core of the question: which hormone is the basis for pregnancy tests?
Systematically review the function of each hormone listed in the options.
Recall that FSH and LH are primarily involved in regulating the menstrual cycle and ovulation.
Remember that progesterone's main role is to prepare and maintain the uterine lining for pregnancy.
Identify hCG as the unique hormone produced by the developing placenta after implantation, making it the specific marker for pregnancy.

Concept Tested & Keywords

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