## Facts

- Mexico City’s legislature amended its criminal code and health law in April 2007 to (1) define “pregnancy” as beginning at implantation and (2) define “abortion” as termination of pregnancy after the twelfth week of gestation.
- The reforms decriminalized consensual or self-induced abortion during the first 12 weeks, preserved criminal penalties after 12 weeks, and maintained a separate category for forced abortion.
- The health-law amendments required public health institutions in Mexico City to provide abortion services on request within the first 12 weeks, even for women with access to other health coverage.
- Two abstract constitutional review actions were filed in May 2007: one by the National Human Rights Commission and one by the Federal Attorney General.
- The challengers alleged violations of constitutional protections and the federal allocation of powers, arguing that the reforms improperly failed to protect prenatal life and conflicted with international human-rights instruments.
- The cases were joined and decided by the full bench of Mexico’s Supreme Court in August 2008.

## Issues

1. Whether the constitution requires protection of prenatal life from conception such that decriminalizing abortion in the first 12 weeks is unconstitutional.
2. Whether Mexico City’s legislature had constitutional authority to redefine and partially decriminalize abortion and to impose related public-health service obligations.
3. Whether the reforms conflict with Mexico’s international human-rights obligations concerning the right to life and the rights of women to health, equality, and non-discrimination.

## Decision

- The Court upheld the challenged Mexico City provisions decriminalizing abortion up to 12 weeks and requiring public provision of services within that period.
- The actions were held partially admissible but unfounded as to the core reforms; certain other challenged provisions were dismissed on procedural grounds.
- The Court concluded the constitution does not establish an explicit, categorical rule protecting life from conception that would bar the legislature’s chosen regulatory approach.
- The Court found Mexico City acted within its constitutional competences in criminal-law definition and in organizing health-service delivery.
- The Court determined the reforms were consistent with applicable international human-rights commitments, including consideration of women’s rights to health and equality.

## Legal Principles

- Absent an explicit constitutional rule fixing the beginning of legally protected life as a categorical bar, legislatures retain discretion to define criminal offenses and set gestational thresholds, subject to constitutional limits.
- Protection of prenatal life may be pursued through regulatory means other than criminal punishment, and criminal law need not be the exclusive or mandatory instrument.
- Constitutional review may allow legislative balancing between state interests in prenatal protection and women’s rights to health, equality, non-discrimination, and personal autonomy.
- International human-rights provisions on prenatal protection that use qualifying language (e.g., “in general” from conception) do not necessarily mandate absolute criminalization at all stages.
- Subnational entities may legislate on local criminal matters and related health-service measures when acting within the federal constitutional allocation of authority.

## Conclusion

Mexico’s Supreme Court sustained Mexico City’s 2007 reforms that decriminalized abortion during the first 12 weeks of pregnancy and required public health institutions to provide services upon request, holding that the constitution did not compel a conception-based criminal prohibition, that the local legislature acted within its powers, and that the scheme was compatible with international human-rights obligations.


Acción de Inconstitucionalidad 146/2007 (Mex. Sup. Ct. Aug. 28, 2008)