Ten states (although Florida's enforcement of such laws are under permanent injunction) require a second physician to approve.[25] The U.S. Supreme Court struck down a requirement of "confirmation by two other physicians" (rather than one other physician) because "acquiescence by co-practitioners has no rational connection with a patient's needs and unduly infringes on the physician's right to practice".[29] Pro-choice organizations such as the Guttmacher Institute therefore interpret some of these state laws to be unconstitutional, based on these and other Supreme Court rulings, at least to the extent that these state laws require approval of a second or third physician.[25]