Cal. Penal Code § 5007.7

Pregnant inmates temporarily taken to a hospital outside the prison for the purposes of childbirth shall be transported in the least restrictive way possible, consistent with the legitimate security needs of each inmate. Upon arrival at the hospital, once the inmate has been declared by the attending physician to be in active labor, the inmate shall not be shackled by the wrists, ankles, or both, unless deemed necessary for the safety and security of the inmate, the staff, and the public.