As Jennifer Andrews went into labour on the night of Nov. 10 last year, her mother and husband frantically watched the clock.
If Ms. Andrews could just "hold out" pushing for another half-hour, she'd land herself an 11/11/11 baby, they told the incredulous doctor.
"The doctor looked at us like, 'Are you serious?' I guess people do these things, but at the same time they're thinking, 'You've been in labour for 17 hours. Are you sure you want to wait?'" recalled Ms. Andrews, a 33-year-old teacher's assistant at a Toronto daycare.
In the end, Annabelle popped out at 12:12 a.m., the first of eight babies born in short order at Toronto East General Hospital on the 11th, considered by many around the world to be a lucky day that year.
The timing was fortuitous: Ms. Andrews and husband David had been through two in-vitro fertilization cycles; they were actually on an adoption list when she got pregnant on a weekend getaway to Niagara Falls on Valentine's Day.
"My mom had heard on the news that if you conceived on Valentine's Day weekend, you'd have the baby on the 11th. It all tied together that it would be neat have her born on that day."
At the same time, Ms. Andrews hoped to sidestep a Halloween birthdate: party attendance would be slim with all the other kids out trick or treating. Had she been able to sway the timing of her "spontaneous" birth?
Research suggests yes – a study published in the journal Social Science & Medicine last July showed that women can control the timing of their natural labour around holidays, expediting or delaying the process based on cultural cues.
"There's a lot of mystery around birth timing. Our study suggests there may be this role of individual will," said Becca Levy, lead author of the study and associate professor of epidemiology and psychology at the Yale School of Public Health.
Prof. Levy and her colleagues scanned all American births between 1996 and 2006, looking especially at the weeks bracketing Valentine's Day and Halloween. They speculated that births would spike on Valentine's Day (rife with positive symbols such as cherubs, hearts and flowers), and drop at Halloween, with expectant mothers leery of the day's deathly connotations.
They found a 5.3 per cent decrease in spontaneous births on Halloween and a 3.6 increase on Valentine's Day, which also saw cesarean births swell by 12.1 per cent and induced births by 3.4 per cent. Halloween, meanwhile, showed a precipitous 16.9 per cent drop in C-sections and an 18.7 decline in induced births, suggesting mothers are reticent to schedule births on a day that honours the dead.
"It raises the possibility that cultural beliefs play a role in birth timing. That's something that moms, families and health-care professionals already pay attention to, but it suggests there might be something going on that impacts biology," said Prof. Levy, pointing to prior research that's shown a mother's stress levels can impact the time when she gives birth.
A "mind-body connection" is how Lisa Weston puts it.
Ms. Weston, president of the Association of Ontario Midwives, has witnessed many clients – especially those who aren't first-time moms – controlling their birth times, with some even guessing their due dates correctly.
She chalks it up to hormonal response: Women dump adrenalin into their system and block oxytocin when they're stressed, which prevents the uterus from contracting.
She posits that Christmas "is a stressful time," one that may pre-empt labour. Indeed, very few of her clients give birth on Dec. 25, or on Halloween. Others will not go into labour until their midwives are on call, or put their labour on pause if they have to be transferred from home to a hospital.
"I think women can hold off on their labour or, conversely, signal that it's okay now to go into labour," said Ms. Weston.
She's worked with expectant mothers hoping to avoid dates such as 9/11, as well as certain family occasions: "I had one woman, it was her sister-in-law's birthday. They didn't get along."
Other clients identify special days close to their due dates – especially birthdays of family members who've passed away.
That day for Heather Leech Healy was Aug. 23, the birthday of her father, who died in 1999. A week overdue with her son four years ago, Ms. Leech Healy was induced on Aug. 22.
The young nurse in the delivery room, "a take-charge girl," had also recently lost her father. At 11:35 p.m., she said, "You're ready? Now you're just going to have to wait for 20 minutes."
"She was just cool," said Ms. Leech Healy, a 39-year-old technical assistant in Waterloo, Ont. In the end, Cameron was born at 12:09 on her father's birthday.
"It was special to honour him. It kind of felt like it came full circle. He was gone and this other little boy comes into the world on his birthday."
Beyond holding out, which Ms. Leech Healy acknowledges is "kind of impossible," plenty of women have their own ways of tinkering with birthdates. Parenting message boards teem with home remedies, from having sex to loading up on spicy food, drinking red wine or sipping castor oil, a powerful laxative that can have nasty side effects but releases the hormone prostaglandin, which can trigger labour.
It was two doses of castor oil for 87-year-old Ruth Tinkess, a retired nurse in Burnaby, B.C., who had daughter Brenda on her father's birthday on March 11, 1957, and her son Paul on her sister Pauline's birthday, May 18, 1961.
"Brenda's due date was so close. One of my best friends was a nurse in obstetrics and she said, 'Oh Ruth, just take a little bit of castor oil and go for a swift walk.' That was the trick."
Her father and sister had a "nice surprise," and she had the blessing of her family doctor: "It was not risqué."
Prof. Levy wants to talk to mothers about what they're doing to accelerate or suspend labour: "It's possible that home remedies, behavioural differences, are playing a role. We don't know whether people were taking castor oil or doing cartwheels. There's a lot of information out there about ways to control birth timing."
Ultimately, midwives will not interfere with a healthy pregnancy to induce labour on grandma's birthday. Ms. Weston advises women who are obsessing over a particular day to be "reasonable."
"You can't get into the birth that way. When they're 100 per cent set on anything, a midwife would talk them through alternatives and get to the root of why they feel that way. This way, mothers are more likely to feel satisfied with how things go – not disappointed."