## **Core Concept**
Pregnancy gingivitis is a type of gingivitis that occurs during pregnancy, primarily due to the changes in hormone levels. The condition is characterized by inflammation of the gingiva, which can lead to bleeding, redness, and swelling. Hormonal fluctuations play a significant role in the development of pregnancy gingivitis.

## **Why the Correct Answer is Right**
The correct answer, **B. Increased level of progesterone**, is right because the level of progesterone increases significantly during pregnancy. Progesterone causes an increase in blood flow and vascular permeability, leading to the characteristic gingival changes. It also affects the response to dental plaque, making the gingiva more susceptible to inflammation. The increased levels of estrogen and progesterone alter the subgingival microbial flora and affect the host's response to bacterial products.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Decreased level of estrogen. This option is incorrect because estrogen levels actually increase during pregnancy, contributing to the changes in gingival tissues.
- **Option C:** Decreased level of progesterone. This option is incorrect because progesterone levels increase during pregnancy, and it is this increase that is associated with pregnancy gingivitis.
- **Option D:** Increased level of testosterone. This option is incorrect because testosterone levels do not play a primary role in the development of pregnancy gingivitis.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that pregnancy gingivitis typically appears during the second to third month of pregnancy and tends to resolve after delivery. However, good oral hygiene practices are crucial during pregnancy to prevent or minimize the condition. Regular dental check-ups are recommended for pregnant women to manage and prevent pregnancy gingivitis.

## **Correct Answer:** . Increased level of progesterone