"I think [the parents] are making a social gender statement," said Dr. Ari Brown, a pediatrician in Austin, Texas, and co-author of "Baby 411: Clear Answers and Smart Advice for your Baby's First Year."
Keeping the child's gender a surprise is "not a good parenting choice because it's their identity," she said. "Whether you later choose to reject your identity -- which sex you are -- or not. You are born with a set of parts, and that's who you are."
Brown said she would worry about Storm as the child gets older.
"They do start to look at their parts and ask questions, and they tend to form a gender identity," she said. "Not all boys have to play with action heroes or girls with Barbies. You can certainly raise a child in a fairly gender-neutral home, and if you choose to do that, fine."
"Just because you have testes doesn't mean you have to only play with male-oriented toys," said Brown.
As for the younger siblings, Brown said she thought they might be able to keep mum about their baby's sex in the way that a family might encourage its children not to discuss a personal health matter.
"People keep their own family secrets," said Brown. "But when it comes to this, it just seems silly."
But Storm's family has held firm, at least for now. On a vacation in Cuba this winter with Witterick's parents, the family flipped a coin at the airport to assign the baby a gender temporarily, and for a week they called him a boy.
The social response changed instantly, and people said, "What a big, strong boy," according to an email Witterick sent to the Star. "In fact, in not telling the gender of my precious baby, I am saying to the world, 'Please can you just let Storm discover for him/herself what she (he) wants to be?!."
"Everyone keeps asking us, 'When will this end?'" said Witterick. "And we always turn the question back. Yeah, when will this end? When will we live in a world where people can make choices to be whoever they are?"