Sheng nu cites studies that show that women are now breaking the tradition of "mandatory marriage" to have fewer children or marry later on in life. Other typologically similar terms that are still used in the modern lexicon of other countries and cultures show the concept has existed in some cases as far back as the 16th century. The term spinster was used to describe unmarried or single women of a marriageable age. It wasn't until 2004 when the Civil Partnership Act replaced the word spinster with "single" in the relationship history section of marriage certificates in the UK. Subsequently, at the
Same-sex marriage in Chihuahua modifications to marriage certificates, changing the words "groom's name" and "bride's name" with "names of the contracting parties", thus also applying to same-sex couples. Changes to birth certificates were also made. These changes caused an uproar within conservative groups. In April 2017, the Governor issued an executive order reinstating the words "mother" and "father" on birth certificates. Even though the Supreme Court had ordered Congress to change the Civil Code within 90 days, by December 2017, the Civil Code had still not been modified to comply with the Mexican Constitution by removing the heterosexual definition of marriage. In October 2018,