Please read..need any info you can give, what caused this in my newborn baby?

I had my daughter may 22nd, labor was 3hrs long (water breaking to delivery) the cord was around her neck and was tight, the doc cut it right as her head came out, but her arms from here elbows down, and her legs from the knee down was purple/grey..she was crying and breathing just fine, she also had red spots on her chest/stomach, it took about 2hrs for her to get a normal color..my doc said maybe it was a blockage that unclogged on its own. He did not explain much to me and im going to take her to another doc to get checked..just curious if anyone knows what could cause it (besides the obvious lack of oxygen) but why her limbs??