Which medication is recommended for a pregnant client with HIV to decrease transmission to the fetus?

Zidovudine is the recommended medication for a pregnant client with HIV to help reduce the risk of vertical transmission of the virus from mother to fetus. This antiretroviral medication is known for its efficacy in lowering the HIV viral load when used during pregnancy, labor, and delivery. When a pregnant woman with HIV receives Zidovudine, it can significantly decrease the chances of the virus being passed on to the baby, especially when combined with proper prenatal care and monitoring.

In contrast, Metformin is primarily used for managing type 2 diabetes and does not have any role in HIV management or transmission prevention. Calcium gluconate is a supplement to address calcium deficiencies, while Timolol is a non-selective beta-blocker typically used to treat conditions such as high blood pressure and glaucoma. Neither of these medications has any relevance to HIV treatment or prevention. Thus, Zidovudine is specifically indicated and beneficial in this context.