Conjoined twin boys born in Atlanta share a torso, arms and legs, and because they also share a heart and its circulatory system it will not be possible to separate them, doctors say.

Asa and Eli Hamby were born early Thursday at Atlanta's Northside Hospital in a planned Cesarean section, a hospital spokeswoman said.

In social media postings, parents Michael and Robin Hamby of Alabama confirmed there would be no attempt to separate them.

"I need a lot of prayer for my boys," Michael Hamby said in a video posted on Facebook the night before the delivery.

Conjoined twins, occurring about once in every 200,000 live births, face daunting odds of survival, with 40 to 60 percent stillborn.

Of those that do survive birth, around 35 percent do not survive beyond a few days.

Extensive testing and ultrasound examinations had prepared both the parents and doctors on what to expect, showing the twins were joined side-to-side, a condition known as dicephalic parapagus, a rare form of conjoined twins.

The Hambys, who have a 22-month-old daughter, said they were hoping and praying for the best as doctors prepared to deliver the twins at 37 weeks into the pregnancy.

"We're excited about it, we're nervous, scared," Michael said in the video posted Wednesday evening.. "You name it, but we're going through it."

Relatives and friends of the Hambys gathered at the hospital for the birth.

"Babies are out and so far they are doing AMAZING. Both babies crying their little eyes out!!!" Emily Berdeaux, a relative, wrote on the family's Facebook page early Thursday.

Robin Hamby was reported doing well after the Cesarean surgery.

Michael and Robin Hamby have chronicled the pregnancy on Facebook, posted videos and updates that have garnered thousands of followers.

After the birth the twins were administered medications to aid their joint heart and were intubated to help them breathe, doctors said.

It was expected they would be transferred from Northside Hospital to Children's Healthcare of Atlanta.