The identity of the girl and her family has not been revealed in a bid to protect the new parent's privacy. The birth was at Northeast Hospital in US.
"My daughter and (her) baby are fine, and the baby is absolutely beautiful," Fox News quoted the mother of the girl as saying.
Dr. Abdulla Al-Khan, a leading high-risk obstetrician, has pointed out that the pre-teen's body may not have yet developed to carry a child, despite the fact that she has given birth to a baby boy.
"Her body is clearly not defined for pregnancy with its short stature," Fox News quoted Al-Khan, as saying.
He added: "Her chest is not extensively developed for breast tissue, her bones aren't quite fused, and once you expose a child this young to high amounts of progesterone and especially estrogen, there is (a possibility) that it could halt her growth.
"The textbooks don't even tell you how to deal with a 10-year-old; it's completely different even though we understand the basics.
"Think about how difficult a pregnancy is for someone in their 20s or 30s ... the aches, pains, the sleep deprivation," Al-Khan said. "Now imagine it in a child."
Also, Dr. Keith Ablow, a psychiatrist said: "This is heart-wrenching because you have a kid whose mental capacities can't possibly wrap themselves around what it means to be a mother.
"There are so many psychological minefields in store for her. Feelings of guilt, feelings of wanting to nurture another human being, and yet this is all very, very complex and intense when she looks to her own family to essentially support, and if you will, father her child.
"She has her own life plan, and yet there's another life that should take precedence."
Al-Khan briefed that the youngest documented case of a child pregnancy was in 1939 in Lima, Peru.
A recent report by the Guttmacher Institute claimed teen pregnancies in the U.S. were up 3 percent in 2006.