Fertility experts have highlighted a worrying reason why ultra-trim celebrities like Lily Collins opt for surrogate births — they struggle to conceive due to their super slim frames.
Specialists say that many slender celebs are unlikely to have the level of body fat needed for regular ovulation, when an egg is released for fertilisation.
Speaking to MailOnline, Renee McGregor, a dietitian specialising in eating disorders said natural conception for super slim celebrities would be ‘almost impossible’.
‘Research shows that ovulation occurs only when body fat ratio is above about 21 per cent,’ she said. ‘Generally speaking, if you can see a woman’s abdominal muscles, their body fat percentage is hovering at about 18 per cent.
‘Women won’t be having periods or ovulating with less than 20 per cent body fat – let alone be able to conceive.’
It comes amid rife speculation as to the reason actor Lily Collins opted to have her daughter Tove via a surrogate.
The Emily In Paris star, 35, announced the birth of her first child with film director husband Charlie McDowell last week, expressing ‘endless gratitude’ for the surrogate who helped her become a mother.
But social media users have attacked the couple’s choice, accusing them of taking part in the ‘unethical trend’ of ‘renting womens’ bodies’.
In an emotional post on Instagram, the Emily In Paris star said she was full of ‘endless gratitude’ for the surrogate who helped her to become a mother
Some speculated that surrogacy is often chosen by A-list celebrities as a way of avoiding pregnancy to preserve their looks.
Los Angeles-based fertility doctor Vicken Sahakian has echoed this theory, arguing that ‘social surrogacy‘ allows some women to continue working without having to pause their careers.
She said: ‘For instance, if you are a model or an actress and your income is based on performing and how you look, pregnancy will ruin that for a year if not more.’
But other experts pose an entirely different theory.
McGregor says it’s likely the extreme diet and exercise regimes adopted by famous women that plays havoc with their reproductive system.
‘You don’t have to starve for the body to be under-fuelled. Many of my patients [who don’t have periods] have adopted restrictive diets they’ve seen on social media,’ she explained.
‘Others are doing trendy fasting diets while following high-intensity workouts.
Experts say many celebrities are too slim to conceive naturally, as periods stop if women don’t have a certain threshold of body fat. Pictured: Lily Collins in October 2024.
‘Often the body needs more weight than you might think it needs, following a period of under-nourishment, to “decide” it’s safe to carry a baby.
‘A certain amount of body fat is needed, as well as enough carbohydrate. It only when there’s enough fat and carbohydrate that signals are sent to the brain, firing up the reproductive system.’
Collins, who has spoken openly about her teenage struggles with eating disorders, is one of several slim celebrities who have opted to have children via a surrogate.
Nicole Kidman had her fourth child, Faith Margaret Kidman Urban, via surrogate in 2011, aged 43.
The birth came three years after the star welcomed her first biological child, aged 40, following years of fertility struggles.
Kidman, who has been married to country music legend Keith Urban since 2006, has previously revealed she suffered an ectopic pregnancy and a miscarriage during her 11-year marriage to Tom Cruise.
Cruise and Kidman adopted two children — Bella, now 32, and Connor, now 30.
Nicole Kidman has previously revealed her struggles with infertility. Her youngest child was born via a surrogate.
Kidman and Cruise adopted Isabella, 31, and Connor, 29, in the early 90s but following their split in 2001 the two children sided with their father, and have not been publicly seen with their mother since 2007.
Another ultra-skinny famous face who opted for surrogacy is musician and ex-partner of tech giant, Grimes.
The 36 year-old, who’s real name is Claire Boucher, welcomed the birth of her and Musk’s baby girl — named Exa Dark Sideræl Musk — in December 2021.
The Kill V Maim singer alluded to an explanation in one interview, recalling her traumatic of pregnancy with the couple’s first child, son X Æ A-12.
Grimes recalled being unable to walk on some occasions. ‘He was pressing on my nerves, so I kept collapsing,’ she said in an interview with Vanity Fair.
‘I took a few steps and collapsed. It was kind of scary, because you don’t want to fall a lot when you’re eight months pregnant. So I would just crawl to the bathroom and crawl back or whatever.
‘Like, I haemorrhaged. It was scary.’
Grimes has previously revealed her unusual — and often extreme — wellness habits.
In 2019, she described a daily routine including ‘2-4 hours in a deprivation tank’ (a huge bath filled with salt water in a dark, silent room) , a ‘1-2 hour sword fighting session’ and ’30-45 minutes on an inclined hike at roughly 4-4.5 miles per hour’.
Elon Musk and Grimes were together for four years before calling it quits in 2022.
Grimes, who had her second child via surrogate, has previously spoken of her history of body dysmorphia.
While making her 2012 album Visions, she is said to have hid inside a room for nine days without food in order to optimise her level of creativity.
Other slim celebs who’ve chosen surrogacy include heiress Paris Hilton and Sarah Jessica Parker, who spoke publicly about struggling to get pregnant with her second child.
The absence of periods for more than six months is known medically as hypothalamic amenorrhea or HA – and is estimated to affect between one and three per cent of women aged 17 to 44.
Studies show that up to a third of women with diet-related hypothalamic amenorrhea struggle to get their periods back at all.
The problem lies with a disruption of the signals sent by the hypothalamus in the centre of the brain, which is responsible for the menstrual cycle.
In healthy women, the brain sends signals to the ovaries, instructing them to grow follicles which house an egg, – and, ultimately, triggers the surge of hormones that causes the egg to be released.
If an egg is not fertilised, another surge of hormones spark the shedding of the womb lining – a period. But in hypothalamic amenorrhea, this delicate cascade of hormonal signals is disrupted.
‘The hypothalamus is sensitive to changes in the external environment, especially stress and weight changes,’ explains Dr Lisa Webber, a consultant gynaecologist specialising in irregular periods at St Mary’s Hospital in London.,
‘Women have to reach a certain threshold of body fat for the hypothalamus to signal for the release of an egg.’
It is a problem that experts say extends way beyond the celebrity world.
Paris Hilton had both her children via surrogate. The TV personality said her decision was due to the lasting impact of trauma she suffered as a teenager.
Paris and her husband, Carter Reum, have two children: Phoenix, two, and London, one.
In 2020, Dr Michael Dooley, a former NHS consultant gynaecologist and director of The Poundbury fertility clinic in London, told MailOnline he was also seeing an increase in diet-related fertility problems.
‘It’s become a huge problem,’ he said. ‘It doesn’t take much to tip people into these problems – sometimes it’s just a matter of an extra gym class.’
On social media you’ll find a community of women searching for answers to this problem. On Facebook, ‘No Period. Now What?’, set up by biologist and ex-sufferer Nicola Rinaldi, has more than 2,000 members, with 12,000 followers on Instagram. Not all are recovering from eating disorders – some experimented with a new diet, while others started visiting the gym more frequently.
The longer a woman goes without periods, the higher the risk of a reduction in the number of her eggs, according to Dr Dooley.
‘Women have a finite number of eggs,’ he said. ‘In patients who’ve had hypothalamic amenorrhea, we see fewer than normal.
‘Occasionally, even when periods have come back and ovulation restarts, there’s a reduction in the number of eggs released for fertilisation.’
Despite this, there’s ‘no evidence’ that those with a history of hypothalamic amenorrhea will struggle to conceive — so long as they’ve gained sufficient weight to regain their menstrual cycles, according to Dr Dooley.
At the end of 2021, social media influencer and wife of McFly star Harry Judd, Izzy Judd, told The Mail on Sunday of the devastating impact an eating disorder had on her fertility.
‘If I stayed with family, I’d take my own food, and I avoided going to friends’ houses for dinner,’ she said.
‘I was doing high-intensity exercise classes four or five days a week. It was too much to keep my body working properly, and my periods stopped.
‘It’s not surprising my body wasn’t fertile. But at the time I didn’t join the dots.’
Izzy, now 40, said her sporadic eating and intensive workout regime meant she didn’t have periods for three years, and struggled to conceive for two years, leading the couple to turn to IVF.
The treatment proved successful and they welcomed Lola Rose Emma Judd in 2016.
A picture shared on Instagram by Izzy Judd showed her dressed in a bikini with her killer abs on display while clutching a baby.
At the time the picture was taken – in 2018, and after the birth of her second child, Kit – Izzy, wife of Harry Judd, former winner of Strictly and drummer with pop band McFly, was battling an ‘unhealthy obsession with losing weight’
She went on to have two further children, conceived naturally — Kit, six, and Lockie, now three.
However, she suffered disordered eating and infrequent periods in the years before conceiving her second child.
Although Izzy never went to the GP for a formal diagnosis, she saw a private therapist who offered cognitive behavioural therapy – the gold-standard therapy for eating disorders.
And the couple’s desire for a third child was a motivating factor. Izzy tasked her husband with cooking all meals.
‘I said, “I don’t want to know if there’s a spoonful of sugar in there. Just don’t tell me.”
‘I stopped all exercise and starting eating breakfast again, like porridge and granola.’
After four months, Izzy had a period. ‘I started feeling things I hadn’t felt for years – I knew my body was working again.’
A month later the couple conceived naturally, and in September 2021, Lockie, was born.
Izzy said: ‘It’s been one of the hardest things I’ve had to do. Lockie is a blessing – he’s a reminder of my huge achievement and the fact I fought one of my biggest battles to have him.’
