A screen-shot of a gender reveal event is seen at the Santa Rita Mountain's foothills.

It was supposed to be a happy moment, a chance to declare the sex of a soon-to-be-born baby with a blast of color and burst of attention on social media.

But the gender reveal party explosion that killed an Iowa woman last weekend highlights the extreme lengths to which some families go to advertise on social media that they're expecting a boy or a girl.

gender reveal parties have grown increasingly popular and elaborate, with smoke, confetti or colored treats to symbolize the soon-to-be-born child's biological sex.

But what began as a lighthearted, intimate gathering with family and close friends has morphed into a spectacle with guns, explosives and wild animals to maximize shock value - with sometimes dangerous consequences.

"There's this huge pressure to publicize these once-private moments," said Carly Gieseler, an associate professor at the City University of New York's York College, who has studied the rise of gender-reveal parties.

The explosion from the reveal ignited the 47,000-acre Sawmill Fire. 

"You get that outside validation that what you did was unique, that it was extra special. It drives celebrations to the extreme because you're trying to do the thing that no one's done before."

Gieseler said the number of gender reveal parties has risen over the last decade but speculated that the recent string of accidents could cause it to decline.

The homemade explosive that killed 56-year-old Pamela Kreimeyer in Knoxville, Iowa, on Oct. 26 was just the latest example.

The device was meant to spray colorful powder into the air, but instead exploded like a pipe bomb. Kreimeyer, who was standing 45 feet away, died instantly when a piece of debris struck her head.

And in separate instances over the last two years, couples announced their child's sex by putting items into the mouths of their pet alligators - a watermelon filled with blue Jell-O in Louisiana and a pink-powder-filled balloon in Florida.

The use of homemade explosives is particularly concerning to fire officials, who worry about one-upmanship and copycats.

Event planners say they've seen an increase in formal gender reveal parties in recent years. 

"These explosives are very unpredictable," said Ron Humphrey, a special agent in charge of the Iowa State Fire Marshal Division. "You can set 10 off and get 10 different results. If we can get any message across to people, it's to tell them simply not to do it."

Event planners say they've seen an increase in formal gender reveal parties in recent years. Most draw between 30 and 50 people, and some couples even rent event halls for their announcement, said Bonnie Rosa-Mosena, a Des Moines-area wedding and event planner.

"It's not enough just to have grandma and grandpa there," she said. "They want all of their friends. It's a big party."

Rosa-Mosena said one of her client couples used a confetti cannon for their gender reveal party, but guests stood far away when it was fired. Another client revealed the baby's gender while skydiving with a blue aerial flare, signaling a boy.

Associated Press