"I'm arguing for more research to understand some of the phenomena which are currently not understood," he told the British Association science conference.
More than one million test-tube babies have been born since Louise Brown, the world's first, 25 years ago and fertility treatments have advanced in the last quarter century.
But Winston said mutation rates in cells after embryo-freezing, which is being done in fertility clinics around the world, should be looked at.
"That seems to me to be a critical question," he said.
Winston is not suggesting that fertility treatments should be stopped or that in-vitro fertilization (IVF) is dangerous but that doctors and scientists should be more cautious.
"We should not be embarking on treatments which are not seen as being essential to the patient," he said.
He believes that as new techniques have been developed, others which could have benefited patients, such as ovulation treatments and better surgery, have been ignored.
"I think it is rather sad that tubal surgery has been written off. It is still a phenomenal treatment. Overall, in selected cases, it is probably more successful than IVF and has a big advantage because it cures infertility," he said.
"IVF is just a one-shot way of getting a baby."
He added that better control over IVF would also lead to a reduction in multiple births, which can be dangerous for both mother and babies.
An estimated one in six couples suffer from infertility. IVF and a technique for male infertility called intracytoplasmic sperm injection (ICSI) are among the most popular fertility techniques.
