In 1953, Lucy Ricardo gave birth to Little Ricky — and Lucille Ball to Desi Jr. on the same date. This was not a coincidence.
Although not the first TV pregnancy — it was the second — it was still a Big Deal (even though the show used the euphemism "expecting" throughout the real-time pregnancy.) The birth episode, "Lucy Goes to the Hospital," was planned to run the same day Ball gave birth via C-section. The stunt worked: the episode was the most-watched of its time, pulling down 71.7% of the American viewership.
Watch the hilarious scene when Lucy's labor began: