Why so many babies are born in September
If it feels like you have a calendar full of birthday parties and never-ending gifts to buy, you wouldn’t be the only one.
While September is mostly associated with the beginning of autumn, children going back to school, and of course, pumpkin spice lattes (IKYK), it’s also the most popular month for birthdays.
That’s right, as reported by The Telegraph, according to data from the Office for National Statistics, the ninth month of the year is when the most newborns enter the world, triggering a mini baby boom.
The latest data for 2024 showed that seven of the top 10 most common birthdays in 2024 fell in September, nine months after Christmas.
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But what is it about the festive period that gets people so in the mood? Tyla spoke with fertility experts and doctors to reveal the truth behind the trend.
Christmas and New Year are big drivers
If you quickly do the maths, you’ll work out that a lot of the September babies will have been conceived in December the year prior.
Speaking to Tyla, GP and founder of The Female Health Doctor clinic, Dr Nikki Ramskill, explained: “When I used to work in obstetrics, September always felt like an incredibly busy month on the labour ward. We used to joke about all the ‘Christmas babies’ arriving because, if you count backwards, babies born towards the end of September may well have been conceived somewhere around the festive period.
“There are some obvious reasons why that could happen. People have time off work, so couples may spend more time together; there are Christmas parties and New Year celebrations, routines change, and work pressures may temporarily ease. That all equals more opportunity for sex.”
Dr Yusuf Beebeejaun, who works at the St Paul's Create Fertility Clinic, agrees that ‘one of the simplest explanations may actually be the most obvious’.
He added, “Over Christmas and New Year, couples often have more time together, fewer work commitments and a welcome break from the usual daily routine.
“If you're already trying for a baby, having a little more time, privacy and opportunity to be intimate certainly doesn't hurt.”
The expert continued: “There is also something about the festive period that makes people think about family and what they want from the year ahead. For some couples, Christmas and New Year can be the point where they decide they're ready to start or grow their family.”
Some parents deliberately plan
While some pregnancies will have been the result of some, ahem, spontaneous Christmas magic, others will have been specifically planned.
Dr Ramskill told Tyla that UK public health data has previously estimated that 45% of pregnancies in England are unplanned at the time of conception, meaning more than half are planned, and for some couples, that planning may include thinking about when they’d ideally like their baby to arrive.
The expert revealed: “September is particularly interesting because of the English school year. A child born in September will usually be one of the oldest in their year, whereas a child born the following August can be almost a full year younger than some classmates.
“That’s quite a developmental difference when children are only four or five years old, so it’s understandable that some parents may take this into consideration when deciding when to start trying.”
However, it’s important to bear in mind that Christmas doesn’t cause any biological increase in fertility, and even perfectly timed sex doesn’t guarantee pregnancy.
The fertility expert explains how conception depends on sex happening during the fertile window: sperm can survive for up to around five days in the female reproductive tract, while an egg can generally be fertilised for around 12–24 hours after ovulation.
Dr Ramskill warned: “We also need to be cautious about counting backwards nine months from someone’s birthday. Pregnancy is medically dated from the first day of the last period rather than the date of conception, and babies can arrive weeks early or later than expected.
“So a September birthday doesn’t automatically mean someone’s parents had a particularly merry Christmas!”
Is there a best time of year to try for a baby?
If you’re holding out until Christmas to try for a baby because of the amount of September births, it might be worth rethinking your plan.
Dr. Beebeejaun advises: "If you're trying to conceive, your own fertile window matters far more than the season. Your chances are highest around ovulation, particularly in the few days leading up to it.
"What Christmas can provide is simply more opportunity. Trying for a baby can be surprisingly difficult to fit around long working days, travel, stress and two people's schedules. Having a week or two at home together removes some of those practical barriers."
He concluded: "Ultimately, there's no 'best season' to try. Age, ovulation, egg and sperm health and having regular sex during the fertile window are all much more important than whether it's summer or winter outside."
Topics: Parenting, Pregnancy, Health, Real Life, Life, Sex and Relationships
Madison Burgess