I have two kids, and my coding time is suffering. How the heck did you code while up with your kid at 3am? What was the kid doing??
Clients had no idea how delicately I was hitting the keys when writing their code. Deadlines could be missed if he didn't sleep as expected.
As soon as he woke up it was back to being a full time dad. I like to believe that I'm way more productive now since I've become a father - being a parent that's also part of the workforce requires both discipline and creativity.