Would-be parents undergoing IVF have been warned about experimental add-on treatments that could cause harm or reduce their chances of having a baby.
The alert was issued by a regulator as it also revealed a series of errors including eggs lost due to a miscommunication, a sample being "inadvertently discarded" and equipment faults.
Optional treatments causing concern include extra tests, drugs, therapies and the use of new equipment, according to the Victorian Assisted Reproductive Treatment Authority's 2022 annual report.
Examples included endometrial scratching and some immunotherapies.
The regulator said many optional extras were experimental, have not been thoroughly tested or only tested with limitations such as small sample sizes, bias and insufficient data.
"These limitations mean it is not known if they make a difference to the chance of having a baby or if their use has potential risks," the report said.
"(They) generally come at additional costs to patients and can be very expensive.
"It is important for patients to consider whether the cost of an add-on is justified in their specific circumstances or if having an extra IVF treatment cycle to potentially produce more embryos is a better option."
The regulator is also concerned about some sperm donors using social media, apps and other informal arrangements to organise donations outside of limits set by authorities.
In Victoria, sperm from an individual donor may be used by up to 10 women but the report revealed concerns some people were skirting the rules.
The authority detailed several handling errors over the past year, including an incident where a sample was "inadvertently discarded".
It also highlighted the loss of eggs due to a to laboratory miscommunication plus two incidents of eggs and embryos being lost due to prolonged exposure.
Over the last four years there was a 261 per cent increase in an IVF side effect called ovarian hyperstimulation syndrome that involved a hospital stay of at least one night.
It noted that rate was well above the overall 43 per cent rise in fertility treatments during that time.
There was also a 44 per cent increase in Victorians having donor-conceived babies compared to the previous 12 months and a 30 per cent jump in women with frozen eggs in storage.
Victorian Health Minister Mary-Anne Thomas said it could be an emotional rollercoaster for those facing fertility problems and her thoughts were with people impacted by errors.
She said the Victorian Assisted Reproductive Treatment Authority regulates private IVF providers and took comfort from the number of adverse events trending downwards.
"This is a good thing," Ms Thomas said.
"It's really important that we have a strong regulatory framework around our private providers, these private businesses."
