Drug testing pregnant women?

Asking for my brother:
His now ex gf is pregnant with his child. He left her due to her abysing drugs, cocaine, meth, duster cans... When he left he didn't know she was pregnant and neither did she. Now that she found out she's pregnant (10 weeks) he's worried about he using drugs and harming their child and herself. She has a child from a previous relationship that was taken away because she was driving drunk with him. Can he get a hold of someone and make sure she's staying clean by drug testing her throughout her pregnancy