The emergence of drug-resistant mutations in HIV-1 infected pregnant women in South India following single-dose nevirapine exposure presents a critical challenge in the prevention of mother-to-child transmission of HIV. This study investigates the prevalence and patterns of drug resistance mutations in this vulnerable population. By analyzing viral sequences from a cohort of HIV-1 infected pregnant women who received single-dose nevirapine, we elucidate the dynamics of resistance development and its implications for antiretroviral therapy. Our findings underscore the importance of effective strategies to mitigate drug resistance in this context and advance the goal of eliminating vertical HIV transmission.