Follow up silly question..

Emma

I understand you can’t fall asleep on the sofa with a baby in your lap. But you can do sleep. Sooo.. what’s the rule on sleeping with a baby on your lap in bed? (I always have to hold my baby from 4-5am as he won’t re settle in his cot and I’m so sleepy tired!). He can’t roll and I can keep the covers away from him so I can’t see the harm but feel like I’m missing something! Thanks!