Which of the following is tested in urine for the diagnosis of pregnancy?

IGNOU Post B. SC. Nursing entrance-2019

Obstetrics & Gynaecology

Easy

Appeared in: IGNOU Post B. SC. Nursing entrance-2019

Explanation

Human Chorionic Gonadotropin (hCG) is a hormone produced by the syncytiotrophoblast cells of the placenta shortly after implantation.
hCG levels rise rapidly in early pregnancy and are excreted in the urine, making it the primary marker for urine-based pregnancy tests.
The main function of hCG is to maintain the corpus luteum, which produces progesterone, a hormone essential for sustaining the pregnancy in its early stages.
Detection of the β-subunit of hCG in urine is the basis for most over-the-counter and clinical pregnancy tests due to its early appearance and rapid increase.

Option A: Progesterone is vital for maintaining the uterine lining (endometrium) for pregnancy, but its levels are not the primary marker used for initial diagnosis in standard urine tests.
Option B: Estrogen levels increase throughout pregnancy and are crucial for fetal development and preparing the body for lactation, but they are not used as the diagnostic marker in early pregnancy urine tests.
Option D: Human Placental Lactogen (hPL) is produced by the placenta, but its levels become significant only later in pregnancy. Its primary role is to modify maternal metabolism to ensure nutrient supply to the fetus.

Clinical Relevance

Nursing practice connection: Use the key finding related to Hormonal basis of pregnancy diagnosis to guide bedside assessment, documentation, and the next nursing action.
Nurses must educate patients that the most accurate time to take a home pregnancy test is with the first-morning urine, as it is the most concentrated and contains the highest level of hCG.
It is crucial to explain the possibility of a false-negative result if the test is taken too early, before hCG levels are high enough for detection (usually around 10-14 days after conception).
A false-positive result, though rare, can be caused by certain fertility medications containing hCG or by medical conditions like a molar pregnancy. A positive test should always be confirmed by a healthcare provider.

How to Approach the Question

This is a factual recall question testing knowledge of reproductive endocrinology.
Identify the core of the question: Which hormone is specifically measured in urine to confirm pregnancy?
Recall the key hormones involved in pregnancy: Progesterone, Estrogen, hCG, and HPL.
Think about the timeline of these hormones. Which one appears very early after conception and rises rapidly?
hCG is produced by the developing placenta almost immediately after implantation and its levels double every 2-3 days in early pregnancy.
This rapid rise and its excretion into the urine make hCG the unique and definitive marker for early pregnancy tests. The other hormones are either not unique to pregnancy or do not rise significantly until later.

Concept Tested & Keywords

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E6 Obstetrics Williams p. 6

E6 Gynecology Williams p. 350-421