The politics pursued by the administrations of heads of government in Mexico City at the end of the 20th century have usually been more liberal than those of the rest of the country, whether with the support of the federal government, as was the case with the approval of several comprehensive environmental laws in the 1980s, or by laws that were since approved by the Legislative Assembly. The Legislative Assembly expanded provisions on abortions, becoming the first federal entity to expand abortion in Mexico beyond cases of rape and economic reasons, to permit it at the choice of the mother before the 12th week of pregnancy. In December 2009, the then Federal District became the first city in Latin America and one of very few in the world to legalize same-sex marriage.