Several states now require women who seek medication abortions to be provided with dubious information that the procedure could be stopped, allowing a pregnancy to continue.
But when researchers attempted to carry out a legitimate study of whether these "abortion reversal" treatments were effective and safe, they had to stop almost immediately - because some of the women who participated in the study experienced dangerous hemorrhaging that sent them to the hospital.
By passing these abortion reversal laws, "states are encouraging women to participate in an unmonitored experiment," Creinin said.
Creinin and his colleagues detailed their concerns in a commentary in the journal Contraception, and they will publish their study in January's edition of Obstetrics and Gynecology.
克雷宁和他的同事在《避孕》（Contraception）期刊发表了一篇评述性文章，详述了他们的担忧。他们还将在《妇产科》（Obstetrics and Gynecology）一月刊上发表他们的研究。
Medication abortions, which are used up to 10 weeks into a pregnancy, consist of taking two pills in sequence. The first pill in the regimen, mifepristone, loosens the pregnancy's attachment to the uterus. The second pill, misoprostol, forces the uterus to contract to push out the pregnancy. The pills must be taken consecutively to complete the abortion, and there's a chance the pregnancy will continue if the second pill is not taken.
A total of 862,320 abortions were provided in clinical settings in 2017, according to the Guttmacher Institute, about 39 percent of which were medication abortions. Research has shown that using these drugs is a safe way to end a pregnancy.
Some antiabortion activists and legislators claim that not taking the second pill, or giving a woman high doses of the hormone progesterone after taking mifepristone, can help stop, or "reverse," a medical abortion.
The American College of Obstetricians and Gynecologists firmly states that "claims regarding abortion 'reversal' treatment are not based on science and do not meet clinical standards" and say the purported studies that underpin these antiabortion arguments lack scientific rigor and ethics.