## **Core Concept**
The management of syphilis in pregnant women is crucial to prevent congenital syphilis. The primary goal is to treat the infection effectively while minimizing risks to the fetus. Penicillin is the cornerstone of syphilis treatment.

## **Why the Correct Answer is Right**
Benzathine penicillin G administered parenterally is the recommended treatment for syphilis in pregnant women. It effectively crosses the placenta, achieving therapeutic levels in the fetus, and has a long-standing history of safely treating syphilis in pregnancy. The regimen for secondary syphilis typically involves a single dose of 2.4 million units of benzathine penicillin G.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While doxycycline is an antibiotic, it is contraindicated in pregnancy due to the risk of inhibiting bone growth and causing tooth discoloration in the fetus.
- **Option B:** Ceftriaxone can be used as an alternative in some cases of syphilis but is not the first choice for pregnant women with secondary syphilis. Its use might be considered in cases of penicillin allergy.
- **Option D:** Azithromycin has been studied as a potential alternative for syphilis treatment but is not recommended for pregnant women due to concerns about resistance and efficacy.

## **Clinical Pearl / High-Yield Fact**
A critical point to remember is that pregnant women with syphilis should be treated with penicillin, and an allergy to penicillin should be managed with desensitization procedures if necessary. Also, remember that the Jarisch-Herxheimer reaction, a systemic reaction that can occur after initiating treatment for syphilis, is more common in pregnant women.

## **Correct Answer:** B. Benzathine Penicillin G.