-- What happens when a pregnant woman is arrested and sent to prison?
The vast majority of inmate moms are separated from their infants once they are born. But a few of the new mothers are able to keep their babies with them in prison nurseries, some until they are 18 months old.
The oldest prison nursery program is run at New York's Bedford Correctional Facility for Women, north of New York City. Seven other women's prisons have similar programs.
In 2014, ABC News "Nightline" spent nine months following Jacqueline McDougall and her son Max at Bedford Correctional Facility.
McDougall said she believed it was a help to her. "I think seeing his little face every day and know that I have to take care of him is going to be a big incentive for me. Definitely," McDougall told "Nightline."
Dr. Janet Stockheim, a pediatrician who comes every two weeks to check up on the babies in the prison, including Max, said it can benefit a baby, too, to be raised behind bars.
"The babies aren't aware. They get excellent care," Stockheim said. "They are very well bonded to the mothers."
"Bonding gives a baby trust in the world that they will be taken care of," she added. "The babies do better here than they would on the outside, with some of these mothers."