Dumb question perhaps, as problems with my internet prevent me from opening links; is this a party where expectant parents tell what their baby will be; or a new age reveal of what somebody "Identifies as"?
From the link: (the last sentence points out how ridiculous and dangerous this trend has become)
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What is a gender reveal party?
Celebrated at an earlier stage in pregnancy than a baby shower, a gender reveal party announces whether expectant parents will be giving birth to a boy or a girl.
Often this will be a surprise for the couple themselves. At their 20 week scan - the point at which it is usually possible to tell the sex of the baby - some couples will ask the sonographer to write down "boy" or "girl" on a piece of paper and put it in an envelope. They give this to a trusted friend or relative who organises their gender reveal party.
Guests often demonstrate their gender predictions by wearing pink or blue, then play games before the big reveal.
Although particularly popular in the US, the parties are a growing trend in the UK. Online retailer Party Delights reports an 87% increase in gender reveal-related products over the past three years and attributes the craze to social media and viral videos.
Managing director Claire Grasby says customers are "looking for ever more creative ways to celebrate a pregnancy".
Traditional reveals include a cake with blue or pink sweets hidden inside, a pink or blue confetti-filled piñata or a guest taking off a hat to reveal a pink or blue wig. But more dramatic and potentially dangerous announcements, including fireworks, smoke grenades and burnouts - are becoming more and more common.