Is December 11 Really The Most Fertile Day Of The Year? We Asked A Doctor

Photographed by Ashley Armitage.
Happy December 11th — the most fertile day of the year! Wait, what? 
Today, you might see a few stories going around with headlines like this: "December 11 Is Most Fertile Day of the Year -- Go for It!" Meaning, if you want a baby, have unprotected sex today because there's a good change you'll get pregnant.
Here's the backstory: Back in 2012, sex toy retailer Lovehoney analyzed British birth records and found that the most popular birthday was September 16. Count backwards nine months, and you get December 11 as the most popular conception day.
In fact, Lovehoney found that the ten most popular British birthdays are all in September, and estimated that around 9% of British babies are conceived in December. Every year since then, the media revisits the study and the wink-wink, nudge-nudge headlines return. 
So if you’re trying to get pregnant, will having sex on December 11th increase your chances of conceiving? It's complicated, Dr. Nicole Noyes, system chief for reproductive endocrinology and infertility at Northwell Health, tells Refinery29.
“While theories exist as to why people seem more likely to conceive at that time of year, how fertile a person is really comes down to their personal biology,” she explains. “There isn’t a universal day we can depend on for people to, say, release the best egg. Instead of thinking about the most fertile day to conceive, people who want to become pregnant (or want to avoid it) should take the time to understand their own body and any potential barriers.” 
For most people, Dr. Noyes explains, the most fertile days of the month are the day before and the day of ovulation — so your most fertile days will be different from another person's most fertile days, unless your menstrual cycles are exactly the same. Other factors can affect fertility, though, so it’s important to visit an OB/GYN and fertility specialist. “A comprehensive exam to uncover any common fertility issues that affect egg ovulation or quality is key to understanding how to best position yourself for achieving pregnancy,” Dr. Noyes says.
All that said, it is true that more people conceive around this time of year, Dr. Noyes admits. But she says that's more likely due to factors such as getting time off of work for the holidays rather than any magical conception-enhancing powers in the air. “My personal theory is simply that people are having more sex this time of year, and their own ovulation periods happen to overlap,” she says. “Whether it’s the influence of the holidays or a planned approach, this is the most likely explanation.” 
If you're trying to conceive, don't expect a December 11 holiday miracle. But if you want to have sex today, hey, it certainly can't hurt to try.

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