A crossover no-one saw coming.

That's how many in India are describing Microsoft founder and philanthropist Bill Gates' appearance in an iconic Hindi TV drama with actress and former federal minister Smriti Irani.

Mr. Gates appeared on Thursday night's episode of Kyunki Saas Bhi Kabhi Bahu Thi (Because the Mother-in-Law Was Also Once Daughter-in-Law) to talk about maternal and child health with Irani.

The Gates Foundation has been working on curbing infant and maternal mortality for years with governments in Uttar Pradesh and Bihar - the two northern Indian states with huge populations that are also among the most disadvantaged regions.

Government data shows a significant improvement in maternal and child health indicators over the years, including in the two states. But in a country steeped in patriarchy, challenges remain.

In such a scenario, experts say messaging becomes extremely important to keep the drumbeat going to change norms and to make people more aware of the need to take care of their girls and mothers.

First launched in July 2000, the series had a very successful long innings with several thousand episodes that were broadcast almost daily on Star Plus for eight-and-a-half years before it was discontinued.

In July, 25 years after it first hit the screens, Kyunki... returned for its second innings.

Indian audiences found the show, based on the complex domestic relationship between Irani's character Tulsi and her mother-in-law, riveting. The trials and tribulations of the dutiful new bride had families reorganize their daily routines to ensure they didn't miss out on a single episode.

The four-minute-long segment with Mr. Gates features the Microsoft founder greeting Irani in American-accented Hindi and engaging her in a meaningful exchange about maternal health, nutrition, and the importance of following medical advice during pregnancy.

This unexpected crossover appears to have reignited interest in a series that was once a cornerstone of Indian television, attracting millions of views online and drawing curiosity and amusement from both fans and new viewers alike.

As the show aims to blend entertainment with crucial societal issues, Gates' cameo demonstrates the potential of media to inform and inspire change beyond the screen.