Cold keys
I feel like maybe this particular pregnant woman would probably have heard that losing your keys in the fridge was a pretty common occurrence. It’s right up there with putting your shirt on inside out. No-one would think any less of her.
I think that one of the reasons for the “keys in the fridge” stereotype being used in so many tv shows is that it’s pretty easy to carry your keys to the fridge, realize that you really want a soda, and put your keys down to grab it. Even when you’re not pregnant, but it’ll definitely happen at some point during the three trimesters.