Elite sport may have caused her “out of control” body to miscarry, cycling champion Laura Kenny has said.
Dame Laura, Britain's most successful female athlete, has five gold medals and one silver at three different Olympic Games.
She says she “gave 100 percent” in every training session and race for more than a decade, even questioning whether she had worked hard enough if she didn't throw up after a workout.
But their engagement may have had an impact on her fertility, she revealed.
After marrying cycling phenom Jason Kenny and welcoming her first child in 2017, she miscarried in November 2021 and had an ectopic pregnancy five months later.
This occurs when a fertilized egg implants and grows outside the uterus, usually in one of the fallopian tubes, requiring emergency surgery.
Jason Kenny and Laura Kenny attend BBC Sports Personality of the Year 2024 at Dock10 Studios
Team Great Britain's Laura Kenny and Team New Zealand's Holly Edmondston race during the Women's Omnium Points Race
Pictured: Laura Kenny's sons Monty and Albie: Albie was born in 2017 and Monty in 2023.
“It was all a shock – I went from being so in control of my body to being so out of control,” she told Radio 4's Today programme.
'My body was just going empty and then it was like, 'Well, wait, there's no way we can do this?'
While she successfully gave birth to another son, Monty, in July 2023, she began speaking publicly about the loss of her baby.
Other athletes soon revealed they had gone through the same thing, raising questions about whether elite sport could have a detrimental impact on fertility.
Dr Emma O'Donnell, an exercise physiologist at Loughborough University, said the lifestyle of a professional athlete places a unique strain on the human body.
Dame Laure Kenny hugs Myleene Klass on Loose Women during an interview
Laura Kenny interviews her husband (R) Jason Kenny for BBC TV Paris 2024 Olympic Games
Training at their level burns an incredibly high number of calories, and as a result, athletes typically have very little body fat.
If they don't eat enough food to fuel their workouts, problems with menstrual cycles, such as periods stopping for months or even years, are “very common,” Dr. O'Donnell said.
The main idea is that having a baby requires so much energy that the brain stops reproduction if it thinks there is not enough energy available, he told the BBC.
In the UK, around one in 90 pregnancies is ectopic, the equivalent of around 11,000 a year.
While it is still unclear why they occur, inflammation and scar tissue in the fallopian tubes may increase the risk.
Professor Geeta Nargund, a consultant at St George's Hospital and medical director of Create Fertility, said she sees no “direct link” between sports and an increased risk of ectopic pregnancy.
However, he said there was a potential link between too much intense exercise in the first three months of pregnancy and miscarriage.