Question

At the end of gestation period, the foetal hormones, which cause decrease in progesterone level in mother's blood are ................

• A. adrenaline and nor-adrenaline
• B. parathyroid hormones
• C. thyroid hormones
• D. corticosteroids

Hint:

Foetal corticosteroids play a critical role in triggering labor by decreasing progesterone levels in the mother.

Answer 1

The Correct Option is D

Step 1: Understanding the role of foetal hormones.
During the final stages of gestation, foetal corticosteroids help trigger the decrease in progesterone levels in the mother's blood, which is necessary for the initiation of labor.
Step 2: Analyzing the options.
(A) adrenaline and nor-adrenaline: Incorrect. These hormones are involved in the fight-or-flight response, not in reducing progesterone.
(B) parathyroid hormones: Incorrect. Parathyroid hormones regulate calcium levels, not progesterone.
(C) thyroid hormones: Incorrect. Thyroid hormones regulate metabolism but do not directly cause progesterone decrease.
(D) corticosteroids: Correct. Corticosteroids play a key role in reducing progesterone levels during labor.
Step 3: Conclusion.
The correct answer is (D) corticosteroids, as they help lower progesterone levels in the mother's blood at the end of pregnancy.