The 38-year-old 'Angels' hitmaker's partner Ayda Field gave birth to Theodora 'Teddy' Rose on September 18 but Williams said that her arrival into the world was far from smooth, reported Sun online.
"I cut the cord but, bless her, I cut it while she was still inside Ayda. Teddy was going blue because the umbilical cord was caught around her neck," Williams said.
"I had to be quick with the scissors. It was like the first 30 minutes of Saving Private Ryan down there. It was like Ayda vs Predator. She'd say the same thing. It's an image that won't go away," he added.
The pop star also said that he took in gas and air intended for this wife as she went through labour.
"I had loads of it... Every time Ayda had a contraction I thought, 'I can have gas and air too.' I've got such huge respect for women who have babies," he said.