## **Core Concept**
The management of syphilis in pregnant women requires careful consideration to prevent maternal and fetal complications. Syphilis is a sexually transmitted infection caused by the bacterium *Treponema pallidum*. The treatment aims to cure the infection and prevent transmission to the fetus.

## **Why the Correct Answer is Right**
The correct answer, **B. Penicillin G**, is the drug of choice for treating syphilis in pregnant women. Penicillin G is effective against *Treponema pallidum* and is the only recommended treatment for syphilis in pregnancy. It is administered parenterally, typically as a long-acting benzathine penicillin G, to ensure adequate levels of the antibiotic in the bloodstream. This regimen is crucial for preventing congenital syphilis and its complications.

## **Why Each Wrong Option is Incorrect**
* **Option A:** Ceftriaxone is an alternative treatment for syphilis in non-pregnant individuals but is not the first-line treatment in pregnancy due to limited data on its safety and efficacy in pregnant women.
* **Option C:** Azithromycin has been studied as a potential alternative for syphilis treatment but is not recommended in pregnancy due to concerns about resistance and efficacy.
* **Option D:** Doxycycline is contraindicated in pregnancy due to the risk of inhibiting bone growth and causing tooth discoloration in the fetus.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that pregnant women with syphilis should be treated with penicillin G, and an allergic reaction to penicillin should be managed with desensitization to ensure the use of this life-saving medication. The Jarisch-Herxheimer reaction, a transient flu-like syndrome, can occur after initiating treatment.

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