Some nights my girls will not stay in their rooms no mater how many times I send them back up and sometimes out of desperation I put them in their room and lock their doors, It is just until they fall asleep, which is about 15 to 20 minutes then I go up there and open the doors and check on them, is doing this child abuse? It is not every night just once in a while.

I don't really think so. My sister would not stay in her room. My dad ended up having to hold the door shut to get her to stay in there, after a few nights of this my sister realized she had no choice but to stay in bed. At one point with my own son he would not stay in bed for even a couple of minute, so I ended holding the door shut until he finally would give up and get back in bed, I had to do this a couple of nights to get him to realize he needed to stay in bed. Now when he gets out of bed the second time he does it I tell him if he gets out again I'm going to shut his door, he gets right back in bed and I don't see until morning.

I, too, would hold my sons door closed when he was younger and had moved into his first bed. The freedom that the bed offered was too much for him to resist sometimes. I did lock the door a time or too, but felt guilty and my brain kept screaming "this is against fire code!" so I would stand and hold the door instead. It was all in my head tho, today, looking back, there was no real difference between locking the door and standing there holding it. Sometimes its the only way

Keeping a door closed helps prevent the spread of fire. It's actually safer. I'd only think of it as a safety problem if the child can't get out/be gotten out in an emergency. It certainly isn't abusive unless it is an extensive time (all day and night) without food/water, etc.