New anti-choice regulations drafted by the Arkansas State Medical Board cleared an administrative hurdle Wednesday when the Arkansas Legislative Council subcommittee reviewed the proposals, the Associated Press reports.

The regulations include the requirement to use an “abdominal ultrasound” to detect a fetal heartbeat—a policy that could prove unclear to physicians who provide abortion care in Arkansas.

The Arkansas Legislative Council, comprised of 20 state representatives and 16 state senators, oversees the Bureau of Legislative Research and acts as an organizing committee for the GOP-majority state legislature. Republicans outnumber Democrats on the council 21 to 9.

The regulations were created in response to the Arkansas Human Heartbeat Protection Act, legislation passed by Republican lawmakers in 2013. The bill only became law after the Republican-controlled state legislature voted to override the veto of former Democratic Gov. Mike Beebe.

The proposed regulations would codify the law in Arkansas.

An abortion can’t be performed in the state until the physician determines if the fetus has a detectable heartbeat, under the proposed regulations. The physician is required to use an “abdominal ultrasound” to test for a detectable heartbeat, “as determined by standard medical practice.”

The original language of the bill, which required an invasive transvaginal ultrasound, was amended after lawmakers were criticized for the requirement.

A transvaginal ultrasound often is used within the first six to eight weeks of gestation, and can typically detect a fetal heartbeat, according to the American Congress of Obstetricians and Gynecologists (ACOG). However, a transabdominal ultrasound is used after eight to ten weeks of gestation, and does not consistently detect a fetal heartbeat when used earlier in pregnancy.

Since typically a transvaginal ultrasound is required to detect a fetal heartbeat, the language of the regulations may cause uncertainty for abortion providers attempting to comply with the regulations. The guidelines seemingly conflict with the use of medical devices as determined by “standard medical practice.”

The regulations also state that if a fetal heartbeat is detected, the physician must inform the pregnant person in writing that the “unborn human individual” has a heartbeat and report the statistical likelihood of the pregnancy being carried successfully to term.

The pregnant person must also sign a form acknowledging receipt of the information.

Absent from the regulations was the requirement included in the original legislation that prohibited a physician from performing an abortion if a fetal heartbeat was detected and if the fetus was at least 12 weeks’ gestation.

A federal court in March 2014 permanently blocked the portion of the law banning abortion at 12 weeks, but allowed to stand the portions of the law requiring women to undergo an abdominal ultrasound.

Several bills to ban abortion after detection of a fetal heartbeat have been introduced in recent years, including five this year, but few have been passed by state lawmakers. A North Dakota law that banned abortion as soon as a fetal heartbeat was detected was temporarily blocked while a legal challenge to the law’s constitutionality proceeds in court.