When his wife Robin was pregnant with their son Jay, a 29-year-old Dr. Phil McGraw popped into a doctor friend's office for a quick vasectomy. He described the procedure - and the regret that followed - in the latest issue of Newsweek.

"He didn't have a nurse there, so I actually assisted him by handing him the instruments," he said of the last-minute vasectomy, adding that it's "painful when they kind of pull on it."

A vasectomy is a permanent - though reversible - form of male birth control that cuts the tubes that carry sperm. McGraw,  the self-help guru who has come to be known as Dr. Phil, said having the procedure at such a young age was the biggest mistake he ever made.

"At that age I was a young lion, a doctor with a new practice," he said. "I wasn't focused on family."

Although Robin agreed with the decision to have just one child, McGraw suspects it was because she was pregnant at the time and couldn't look ahead.

"I always thought in our marriage, if we disagreed I would say, 'How important is this to you on a scale from 1 to 10?' On this she would have said 10," he said.

Six years later, McGraw had a vasectomy reversal to reconnect the sperm-carrying vas deferens. Although the procedure is usually successful, some men remain unable to have more children.

After hobbling home, McGraw told his wife about the reversal.

"She jumps in my lap - almost kills me, she's so excited," he said.

Six weeks later, Robin was pregnant with Jordan.

"He is one of the two greatest joys in our life. God, if I had missed that - how dumb. I just shudder at how stupid I was," he said.

McGraw and Robin have been married for 35 years. Their sons, Jay and Jordan, are now 30 and 23.

"I learned you don't make life decisions on the spur of the moment, and you don't make them alone," he said. "I got a do-over on the biggest mistake of my life, and I am delighted that I did."