Updated

Pregnant women who harm their babies by using narcotics while pregnant will face criminal charges under a new bill signed into law this week in Tennessee, a move decried by health and women’s rights organizations.

Republican Gov. Bill Haslam signed the legislation that would allow women to be charged with assault if they abuse narcotics while pregnant and give birth to a child who is dependent on drugs or harmed as a result.

Haslam signed the bill despite calls from health and women's organizations to veto the bill.

National Advocates for Pregnant Women, a New York-based advocacy organization, says despite attempts by other states, Tennessee is the first to pass such a bill. Under the law, the women would be charged with misdemeanor assault.

Haslam said Tuesday after signing the bill that he is aware of the concerns opponents have to the measure and will use updates with the courts and health professionals to monitor its impact.

"In reviewing this bill, I have had extensive conversations with experts including substance abuse, mental health, health and law enforcement officials," Haslam said in a statement. "The intent of this bill is to give law enforcement and district attorneys a tool to address illicit drug use among pregnant women through treatment programs."

Those opposed to the bill were concerned that it would only wind up hurting the babies. They fear that women will not get prenatal care because they'll be afraid of going to jail. They also fear that new mothers will not get their babies help when the infants start to show signs of suffering from drug dependence because the moms are afraid of getting arrested.

The Haslam administration has said that women who seek drug treatment while pregnant and complete the program will not be charged.

Health care workers note that signs of drug dependency can come days or weeks after the baby has been born and first leaves the hospital.

The American Civil Liberties Union on Tuesday called the law dangerous and said Haslam overlooked widespread calls for a veto of the bill, including from doctors.

"Today, the Tennessee governor has made it a crime to carry a pregnancy to term if you struggle with addiction or substance abuse," Alexa Kolbi-Molinas, staff attorney with the ACLU Freedom Project, said in a statement. "This deeply misguided law will force those women who need health care the most into the shadows. Pregnant women with addictions need better access to health care, not jail time."

Tennessee prosecutors had fought for the law. They argued that it was the only way to get mothers into drug treatment and stop so many children from being harmed as a result of their mothers using drugs while pregnant.

The Associated Press contributed to this report