Briana Kalajian, a birth photographer hired by Rhisie Hentges and her husband, Laurent, taking a picture of their newborn Rocco with his father at Long Beach Memorial Medical Center in Long Beach, Calif., June 12, 2012. Birth photography is a small but growing profession chronicling a rite of passage no less significant than a wedding, though trickier to capture on film. (Stephanie Diani/The New York Times) (Newscom TagID: nytphotos428567.jpg) [Photo via Newscom]

Briana Kalajian, a birth photographer hired by Rhisie Hentges, takes a picture of their newborn. Photo: The New York Times

Lynsey Stone doesn't set foot in the shower without placing her mobile phone on a nearby ledge, so she'll won't miss an urgent text from a woman in labour. She schedules holidays 10 months in advance to ensure they don't conflict with due dates, and on family outings she and her husband leave their Texas home in separate cars, in case she needs to race to the hospital.

Mrs Stone, 33, isn't a doctor, nurse or midwife, but a birth photographer. She's part of a small but growing profession devoted to chronicling a rite of passage that is no less significant than a wedding - though a bit trickier to capture on film.

I want to see that moment when I'm in labour 

"In the beginning, I almost thought that people were joking with me, like, 'Really? You want me to come to your birth?'" said Mrs Stone, whose business took off after a pregnant acquaintance, impressed by pictures Mrs Stone had taken of her own family, asked if she'd photograph her delivery.

<a href="http://www.milkphotography.com.au" target="_blank>Milk Photography</a>, a Melbourne-based business, is a member of the International Association of Professional Birth Photographers.

Milk Photography (www.milkphotography.com.au), a Melbourne-based business, is a member of the International Association of Professional Birth Photographers.

The International Association of Professional Birth Photographers now has about 400 members. There are 14 listed in Australia.

"I want to see that moment when I'm in labour," said Rhisie Hentges of California, who paid US$1895 to a photographer document the birth of her first child. (As it happened, she had a Caesarean section and the photographer wasn't allowed in the operating room, although she got many artful shots before and after.)

Still, some hospitals ban photography while women are giving birth. Jacques Moritz, director of gynaecology at St Luke's-Roosevelt Hospital Centre in New York City, said that if someone trumpeted the arrival of her professional birth photographer, "it's going to be, 'Really? Get out of here'". But he said he's seen more women come in "with their 'friend' that happens to have two Nikons with high-quality lenses on them".

The most frequently asked question for photographers: precisely where do you stand when the baby comes out? The answer: generally near the mother's head, unless she requests a crowning shot.

Another frequently asked question: why can't the father, or partner, simply take the pictures?

One answer lies in a picture that Keren Fenton, a birth photographer in Washington, took last year of a new father.

''He passed out on the floor,'' she said. ''I have him in a chair, holding a juice cup and looking really sweaty.''

NEW YORK TIMES