A common hormone “add-on” being offered to IVF patients has been found to have no benefit for pregnancy success, sparking fresh concerns treatments are being sold to boost a woman’s chances of conceiving without any clear evidence they work.
The study, led by researchers at the University of Sydney and published in the Human Reproduction Update on Tuesday, found that intrauterine administration of the hormone human chorionic gonadotropin (known as hCG) before embryo transfer does not increase pregnancy or live birth rates.
Doctor Rui Wang, lead author and academic lead of the Evidence Integration Group at the National Health and Medical Research Council’s clinical trials centre, said the message for patients and clinicians was clear.
“This add-on does not improve fertility outcomes,” Wang said. “This hormone shouldn’t be routinely offered as part of IVF treatment.”
The hormone is essential in IVF, acting as a “trigger shot” for egg maturation and a key indicator of pregnancy.
However, when it is used in intrauterine administration, which involves injecting the hormone directly into the uterus shortly before embryo transfer to enhance implantation, no benefits could be detected.
The hormone procedure is used in Australia and across the United States, Europe and parts of Asia, and has been promoted as an IVF add-on since the early to mid-2010s to improve implantation.
Earlier reviews had suggested intrauterine hCG was one of the most promising IVF add-ons, reporting significant improvements in pregnancy rates. These findings were widely cited and influenced clinical practice across the world.
However, Wang said when the team of researchers looked in detail at the raw data behind these studies, rather than on published results, they found claims about the positive effects did not stack up.
As part of their scientific analysis, researchers examined 28 randomised trials conducted across several countries that tested intrauterine hCG before embryo transfer, and seven high-quality trials involving more than 2200 IVF patients who met the criteria.
The researchers found that the procedure did not improve live birth rates or clinical pregnancy rates.
“There was no evidence of benefit in any group we analysed, including fresh or frozen transfers, different embryo stages, or different doses,” Wang said.
Researchers believe it is the tip of the iceberg and pointed to a wider problem where some treatments and add-ons are adopted into practice based on unreliable evidence.
Natalie Pennisi, who was diagnosed with endometriosis in her 30s, has spent a decade undergoing fertility treatment.
She has undergone 20 rounds of IVF, which have taken a toll on her body and mental health.
“It’s changed my life. It’s changed who I am as a person,” the 48-year-old who works in public relations said.
During some of her treatment, Pennisi has opted to use add-ons after advice from her healthcare team and after doing her own research, but she added the groundswell of add-on therapies was overwhelming, and it was difficult to understand the treatments that were effective and ones which had no benefits.
“In my experience, one of the most important aspects of a successful treatment outcome is choosing a fertility specialist where you feel comfortable enough to ask all the questions,” she said.
“This gives you the best opportunity to be fully informed about the treatment options available so you can decide together what’s right for you.”
Wang said the findings highlight growing concerns about unreliable or untrustworthy trial data in women’s health research, particularly in areas where evidence is rapidly translated into clinical care.
Professor Robert Norman, an expert in reproductive medicine at the University of Adelaide, said while initially, there was a reasonable basis for testing the effectiveness of hCG, mounting research suggested there was no strong evidence for its use.
“The embryo produces hCG before it implants and therefore it’s communicating with the mother before it’s even burrowed into the womb, so there was a very logical reason for looking at it,” Norman said.
“The other thing about hCG, is it’s very cheap, and it’s one of the drugs that you can buy easily at the pharmacy, but many trials have shown that probably we need to close the door on it.”
He said the use of often costly “add-on” treatments sold to boost a woman’s chances of conceiving through IVF without clear evidence they work had been a growing concern for years.
“Where it’s expensive and complicated and technically difficult… then we get particularly concerned about it,” he said.
In Australia, intrauterine hCG typically costs around $50 to $100 per procedure.
While relatively inexpensive compared to the overall cost of IVF, it is not always clearly listed or itemised by clinics, and patients may combine it with several other add-ons across repeated treatment cycles.
In 2024, it was revealed a costly IVF technique, known as Intracytoplasmic sperm injection, commonly used in Australia was being unnecessarily sold to thousands of patients and could even be reducing their chances of having a baby.
Last year, researchers from three universities also warned about the rampant use and marketing of IVF add-on services.
An analysis of the non-core services being offered to Australian fertility patients by University of Melbourne researchers, revealed 44 treatment types ranging from free to $5000, including ovarian plasma injections, genetic embryo testing and endometrial scratching have little to no influence on the chances of having a live birth, pregnancy or miscarriage.
Australia’s health ministers have ordered a rapid review of the nation’s assisted reproductive sector following a series of bungles and scandals.
Wang said researchers now wanted to apply their approach more widely to identify which IVF interventions work and those with minimal or no benefit.
“The bottom line is all the intervention provided to the patient should be backed up by trusted evidence,” he said.
Be the first to know when major news happens. Sign up for breaking news alerts on email or turn on notifications in the app.
Melissa Cunningham is a health reporter for The Age. She has previously covered crime and justice.Connect via X or email.