生まれぬ先の襁褓さだめうまれぬさきのむつきさだめ慣用句putting the cart before the horseputting the diapers on before (the baby) is born
口から先に生まれるくちからさきにうまれる慣用句見下した言い方to be born mouth firstto be of an overly talkative disposition since birth