**Core Concept**
The patient's presentation suggests a diagnosis of congenital tuberculosis, a rare condition where the fetus or newborn is infected with Mycobacterium tuberculosis. This occurs when the mother is infected with TB during pregnancy, and the bacteria are transmitted to the fetus through the placenta.

**Why the Correct Answer is Right**
In a pregnant woman with a new diagnosis of TB, the primary concern is the treatment of the mother to prevent transmission of the bacteria to the fetus. The recommended treatment for TB in pregnancy is a standard 6-month regimen of isoniazid (INH), rifampicin (RMP), pyrazinamide (PZA), and ethambutol (EMB). This regimen is effective in treating the mother's TB while minimizing the risk of congenital TB.

**Why Each Wrong Option is Incorrect**
**Option A:** Isoniazid and rifampicin monotherapy would be insufficient to treat TB in pregnancy, as it would not provide adequate coverage against resistant strains of M. tuberculosis.
**Option B:** Pyrazinamide and ethambutol monotherapy would not be sufficient to treat TB in pregnancy, as it would not provide adequate coverage against the entire spectrum of TB pathogens.
**Option C:** This option is incomplete and does not provide a clear treatment strategy.

**Clinical Pearl / High-Yield Fact**
In pregnant women with a new diagnosis of TB, it's essential to initiate treatment promptly to prevent transmission of the bacteria to the fetus. The World Health Organization recommends that all pregnant women with TB receive a standard 6-month regimen of INH, RMP, PZA, and EMB.

**Correct Answer: C. Isoniazid, rifampicin, pyrazinamide, and ethambutol for 6 months.**