It's a testament to Lucille Ball's clout that she managed to convince CBS executives — along with corporate sponsor Phillip Morris — to write her real-life pregnancy into the show's plot in 1952, especially considering the industry's priggish use of twin beds for married couples. The network's bigwigs were so nervous about the idea that members of the clergy were brought in to oversee the writing of the seven episodes that mentioned Ball's pregnancy, while the word "pregnancy" itself was banned from the script in favor of "expecting."
Ball did such a thorough job of intertwining reality and the show that she even scheduled the caesarean delivery to correspond with the airing of the episode in which her on-air persona gives birth; it remains one of the most viewed telecasts in history.