Sitting around the dining table of their French Quarter home, Raney-Mills and Sean Kiely share their story about learning their first child's gender in the sweet style only beaming couples can — by finishing each other's sentences.

  "Sean's an engineer and he needs details," Raney-Mills says. Her due date is Sept. 26.

  "Well, I didn't want to waste my time coming up with a boy's name if it was a girl, or a girl's name if it ended up being a boy," Sean says.

  Raney-Mills had heard about a party where guests learned the child's gender along with the parents-to-be via the presentation of a pink cake for a girl or blue cake for a boy.

  "We wanted something ceremonial, but we wanted it to be just us," she says. "We wanted it to be private and not in a doctor's office."

  A few months ago, they visited their obstetrician for an ultrasound and left the doctor with a piece of stationery, an envelope and instructions to write down the baby's sex, seal the envelope and return it to them. The couple took the sealed envelope to Raney-Mills' longtime friend Sarabeth Hudson, who had been a bridesmaid in the Kielys' wedding. It was Hudson's job to bake the cake and keep the secret.

The Kielys' tale reflects a strong trend of expectant couples finding out the gender of their babies months before they are born.

  On the flip side, not everyone wants to know ahead of time, as was evident last week as the world reveled in anticipation of the birth of Prince William and Duchess Kate's first child, whose gender was unknown prior to delivery. The excitement hit a crescendo as the couple announced the baby was a boy, third in line to the throne of England.

  Various parenting magazines and blogs cite a figure of 50/50 as the percentage of couples who want to know the gender in advance and those who chose to wait until birth. Among those who want to know, "gender-reveal" parties have become very popular. Unlike the Kielys, many couples choose to invite friends and family to the celebration, and ways to reveal the gender range from colored balloons, filled candies, flowers, boy or girl dolls and more.

  Improved technology allows obste-tricians to identify the sex of the baby in utero, which is one reason gender-reveal parties are popular. Most expectant mothers have an ultrasound imaging test between their 18th and 20th weeks of pregnancy, a point at which the sex often can be determined. Amniocentesis, a prenatal screening for potential genetic problems, also can identify gender.

  The surge in gender-reveal parties began a few years ago, but the celebrations have grown in size and scope. As Evonne Lack wrote in her article "8 Hot Tips for Your Gender Reveal Party": "Cutting into a cake with pink or blue filling is so two years ago. A 'gender reveal' extravaganza, on the other hand — complete with games, favors and a Pinterest board? Now you're talking!"

Sarabeth Hudson says she felt "like a kid that hadn't done their homework" as she searched for hard-to-find ingredients to bake the cake she wanted to present the Kielys. She selected the recipe from her favorite online recipe site,

  "A cake is an occasion," says Hudson, an avid cook and baker. "It's a very simple cake, but it doesn't use flour. It calls for marzipan, an almond paste. I couldn't find it anywhere and was freaking out a little bit. ... [The Kielys] had given me the card (from the doctor) and were waiting on the news and I'm running all over looking for almond paste!"

  Hudson finally found it at French Quarter bakery/coffeeshop Croissant d'Or. She baked the cake, adorned it with white icing and jasmine flowers, placed it in a glass-domed serving dish and presented it to the Kielys at the intersection of Royal and St. Peter streets.

  Sean and his wife walked the few blocks to their home and held a private ceremony in the courtyard. As Raney-Mills read aloud from William Blake's "A Cradle Song," Sean cut into the cake. The juice that squirted out "looked kinda pink" Sean says, but a deeper cut revealed — blueberries. A boy.

  "It was the happiest I've seen him look in his life," Raney-Mills says. Sean counters with, "Raney-Mills then admitted she want-ed a boy the whole time."

  The couple shared a celebratory dinner out together and later ordered blue balloons and flowers to be delivered the next day to their parents, who live out of state.

  What will they name their son? That's yet to be determined, but for now, they're calling him "Spy Boy."