Mexico's supreme court on Wednesday let stand a right-to-life amendment to the Baja California state constitution that says life begins at conception and effectively bans elective abortions in the northern border state.
The ruling appeared to allow Mexican states to decide individually on the abortion question, though the court has also agreed to review a similar amendment from the north-central state of San Luis Potosi.
Sixteen of Mexico's 31 states have adopted right-to-life amendments that severely restrict abortions, though almost all continue to allow it under some circumstances like rape or danger to a mother's life. Only Mexico City has legalized abortion on demand in the first trimester.
Seven justices of the 11-member court voted to overturn the amendment, arguing it was a federal issue, or could violate federally guaranteed rights. But eight votes are needed to overturn a law on grounds of unconstitutionality, meaning the amendment stands.
Some justices argued that Mexico's 31 states have the power to expand rights existing in the federal constitution, but not restrict any stated there. Some worried the state amendments could restrict rights of women.
The federal constitution does not take a position on when life begins, and while some justices argued there are implicit guarantees for the rights of fetuses in the document, most tried to stay away from arguments over abortion itself.
The court said in a statement that it "based its analysis strictly on constitutional issues. That is, the issue under debate was the power of the states to legislate on topics that are not expressly determined by the federal constitution."
Abortion opponents like the National Fraternity of Christian Evangelical Churches applauded the result, saying the case had not become a dogmatic debate.
"Neither dogmas nor religious positions won, but on the contrary, it was a recognition for the secular nature of government and respect for the law, all of the body of laws, national and local," the group said.
The Baja California amendment was passed by the state legislature in 2008, took effect in 2009 and was quickly challenged in court by state human rights officials.
In a landmark 2008 ruling, the supreme court upheld Mexico City's law legalizing abortion by an 8-3 vote.
Both decisions appeared to indicate strong support on the court for state's rights, or possibly an unwillingness to institute a nationwide ban on, or nationwide approval for, abortion.
Allowing individual states to determine such issues may be the path of least conflict, but some women's activists warned it could create two classes of women: those with the money to travel to Mexico City for a safe, legal abortion, and those in outlying states who might decide on illicit, back-alley abortions.
Mexico City's governmental Human Rights Commission said it "regrets that this decision by the supreme court will worsen the serious public health problem of clandestine abortions in unhealthy conditions."
"It is also very grave that a supposedly constitutional and democratic government like Mexico's establishes different levels of human rights protection for women, depending in which state they live in," it added.
Still, some supporters of a woman's right to choose an abortion took some comfort from Wednesday's vote, which fell just one justice short of overturning the right-to-life amendment.
"There is one piece of good news: That is that seven of the 11 justices were defending the rights of women," said Regina Tamez, director of the nonprofit Information Group on Informed Reproduction.