Gender reveal party

A gender-reveal party is a party held during pregnancy to reveal the baby's sex to the expectant parents, family, and friends. Prenatal sex discernment technology furnishes the necessary information. Originating in the United States in the late 2000s, gender reveal parties are common only in the English-speaking world.
It is distinct from, but sometimes combined with, a baby shower, where the primary activity is giving expecting parents gifts for their future infant. The gender reveal party often involves gender stereotypes such as pink and blue denoting girls and boys.
The practice is controversial and has been criticized for reinforcing gender stereotypes. The implied binary gender essentialism of the practice has resulted in LGBT+ community criticisms, particularly from the transgender and intersex communities.
History and development.
The gender reveal party developed in the late 2000s. An early example was recorded in the 2008 posts of then-pregnant Jenna Karvunidis on her ChicagoNow blog "High Gloss and Sauce" announcing the sex of her fetus via cake. YouTube videos can be found as early as 2008 and 2009, becoming significant around 2011, after which the trend continued to grow through the 2010s.
In 2019, Karvunidis observed an increase in extreme reveal events over the preceding five years, with parents "burning down forests and exploding cars, bringing alligators into the mix". She expressed regret at having helped start the trend, learning how the LGBT and intersex communities feel, and finally revealing the daughter they announced back in 2008 to be a gender-nonconforming individual who wears suits while still identifying as female. After the 2020 El Dorado Fire was started by a malfunctioning pyrotechnical device at a gender reveal party, Karvunidis pleaded for people to stop staging such events.
Comparison to baby showers.
Baby showers, a traditional prenatal celebration, have some key differences with gender-reveal parties. Primarily, the focus on gender-reveal parties is fetal sex, while baby showers focus on the giving of supplies and items for the future infant to the expectant parent(s). Traditionally, baby showers are for women only, while gender-reveal parties have no inherently-associated gender restriction and attendee limitations (if any) are determined by the pregnant individual or couple. Some couples combine the two.
Spread and mediatization.
The trend was popularized on social media platforms such as YouTube, Instagram, and Pinterest, although it originated before the latter two. This mediatization has significantly boosted the likelihood of expectant parent(s) to have or take part in gender-reveal parties. Internet remix culture lends the practice great receptivity toward individual creativity, a factor in their growing popularity. Demographic research shows the most gender-reveal parties are done by expecting parents that are middle-class, heterosexual White Americans who are married or partnered.
Planning the event.
The focus of gender-reveal parties being the fetal sex, such information is a prerequisite. This can be determined at or after the gestational age required by the method being used. For ultrasound, the most common method, the earliest this can be reliably done is approximately 65 days, but it is typically done at around 20 weeks. Both the fetal sex and party are typically held during the second trimester.
Post-examination knowledge of the fetal sex by the parents varies. Most commonly, a third party (sometimes called a "gender guardian") is entrusted with the fetal sex and it remains a secret from the parents until the reveal. This person is responsible for making party arrangements to ensure the reveal happens without the prior knowledge of the parents. However sometimes, it is known by the parents prior and the reveal is specifically for attendees. 
To help maintain the mystery, party decorations are typically heavily gendered, but ambiguous and androgynous when taken as a whole.
During the event.
While the focus remains on the fetal sex, the reveal is typically the climax of the party. Prior to the reveal, party games are common where attendees or expecting parents guess or assert the fetal sex. This can also take the form of competition between a "Team Pink" and "Team Blue" of which parents or participants may form.
Sometimes the event includes features of a baby shower. If this is the case, gifts may be given or opened at a specific time before or after the reveal.
The reveal.
Most reveal methods utilize gender-associated colors, most typically blue and pink representing male and female respectively, decorated with other gender-associated items. The method of reveal varies; common methods involve cutting special cakes, launching or popping balloons, confetti/streamers, piñatas, colored smoke, and Silly String. Other seasonally-related items such as Easter eggs, Jack-o'-lanterns, Christmas presents, or Fourth of July or New Year's fireworks may also be incorporated depending on time of pregnancy. 
Once these colors are revealed, both the expecting parent(s) and onlookers are made aware of the fetus's sex, typically to great celebration and comment by attendees. The announcement of a predetermined, sex-dependent baby name can also take place.
Criticism.
The sex and gender distinction underlies many criticisms of gender-reveal parties. The term "gender-reveal" is considered a misnomer by those who acknowledge the distinction. Gender is a social construct in this view, not attached to any biological characteristics, with an individual gender identity impossible to determine medically. Thus, when a reveal of a fetus's genitals is made, it is the sex and not the gender that is being revealed, according to this view.
Furthermore, gender-reveal parties rely heavily on the male-female gender binary, which assumes the child will not be intersex, which occurs in an estimated 1 in 4500–5500 births. Gender-reveal parties have been argued to reinforce gender essentialism, precluding and minimizing transgender identification, which can cause issues with mental and emotional health. Some parents have rejected gender-reveal events because of a greater awareness of gender identity.
Overall the practice heavily reinforces stereotypical gender roles, often utilizing polarizing gender dichotomies in party materials such as "Guns or Glitter", "Pistols or Pearls", or "Wheels or Heels". Critics say that there is no reason to assume that a child would fit neatly into the essentialist dichotomy even where the sex is accurately determined and assigned gender remain the same.
In 2019, Jenna Karvunidis, considered one of the pioneers of gender reveal parties, called for re-evaluation of the practice due to how it might affect transgender and non-binary individuals, also revealing her own daughter's gender nonconformity. After the El Dorado Fire in 2020, Karvunidis decried the parties and pleaded for people to stop having them.
Incidents and injuries.
Some instances of attempted spectacular special effects at gender-reveals have caused injury, death, and even large-scale damage:
Parties for transgender people.
Some families of transgender individuals host gender-reveal parties for transgender family members who come out during these parties.