Mistaken surrogacy is such a juicy premise for drama or comedy, and there are definitely films that play with this idea! One that comes to mind is 'The Switch' (2010), where Jason Bateman's character accidentally swaps his own sperm sample for the donor's, leading to a wild revelation years later. It's a rom-com with a surprisingly heartfelt twist—less about the medical side of surrogacy and more about the emotional chaos of unintended parenthood.
Then there's 'Baby Mama' (2008), where Tina Fey's character thinks she's getting a surrogate through a legit agency, only to discover the woman carrying her child (Amy Poehler) faked the whole arrangement. It's packed with hilarious misunderstandings, though it leans more into the fake-pregnancy trope than true surrogacy mistakes. If you want something darker, 'The Children Act' (2017) touches on ethical dilemmas around parenthood, though surrogacy isn't the main focus. Honestly, I wish there were more films exploring this—it's ripe for tension, humor, and tearjerker moments!