Parents-to-be are throwing parties to reveal their baby's sex to friends and family.

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hough expectant couples traditionally learn the sex of their fetus from a doctor, some are choosing a more festive route — and getting the big news from a cake. The concept of inviting friends and family to share one's reaction — at a "gender reveal party" — first gained popularity after the "Today" show asked Josh and Anna Duggar to cut a white-frosted cake on-air, revealing a pink interior and, thus, the sex of their daughter-to-be. (Josh Duggar is one of the 18 children of "Today" staples Jim Bob and Michelle Duggar.) Recently, Associated Press writer Greg Bluestein documented his own gender-party experience, inspiring a new round of interest. Here, a quick guide to the trend:

Why have a gender party?
To celebrate with loved ones, but also to avoid learning such momentous news in a cold, clinical setting. "My wife Sheryl and I never hesitated on whether we wanted to find out the sex of our baby," says Bluestein, "but we also knew we didn't want the news to come at our doctor's office."

How does it work?
Typically, parents have someone at their doctor's office write down the baby's gender and seal the news in an envelope. Vowing not to peek, the parents deliver the envelope to a bakery, which prepares a cake, cupcakes, or other dessert with a color-coded filling (or prize) inside — blue for boys, pink for girls. One blogger invited guests to wear blue or pink shirts to reflect their personal predictions; another pair of hosts even set up a board for people to vote on the gender. Elaborate, color-coded decorations are popular.

How has the blogosphere reacted?
With a mix of enthusiasm and dismay. Some people disdain the idea of learning such private news in such a public setting. "I think presuming that all of my friends will be as excited as I am to learn the sex of my unborn child is a little, well, presumptuous," says sandymaple at Babble. I can see the concept's appeal, says Theresa Walsh Giarusso in the Atlanta Journal-Constitution, but, personally, I'd prefer to "deal with the emotion [such news might trigger] with my husband and not with an audience." Leo Hickman of the Guardian does not mince words, calling gender parties "self-indulgent and narcissistic" and making an appeal to his fellow Brits: "We still have a chance to repel the advances of such an abomination: let's unite in ignoring this trend."

Sources: LilSugar, ABCNews, Atlanta Journal-Constitution, MamaBuzz, CreateMyEvent, Babble, Guardian