They added it should only be taken at the “lowest effective dose for the shortest possible time” and pregnant women should avoid “indiscriminate” use.
Current NHS advice is that pregnant and breastfeeding women can take paracetamol safely. Both the US and European medicines regulators say the drug is of minimal risk when taken correctly during pregnancy.
More than half of pregnant women worldwide are thought to take it to relieve fever and pain, as alternatives such as ibuprofen are not recommended in later stages of pregnancy.
Today, more than 90 experts, including from the US, Scotland, Denmark, Sweden and France, issued a “consensus statement” calling for precautions to be taken in the use of paracetamol in pregnancy after reviewing 25 years of research on the subject.
They also said there should be targeted research into the apparent increased risk of “neurodevelopmental, reproductive and urogenital” disorders.
They said there were “disturbing increases” in the number of children with cognitive, learning and/or behavioural problems.
Some research also suggested an increased risk of undescended testicles in boys and early puberty in girls.
However, it is also known an untreated fever in a pregnant woman carries a slight risk of neural and heart disorders, and paracetamol helps reduce that.
Andrew Shennan, professor of obstetrics, King’s College London, who was not involved in the research, said it was a “balanced view of the potential risk/benefit of paracetamol in pregnancy”.
Professor Shennan said: “They point out that treating pain and fever could reduce pregnancy risks, and alternatives to paracetamol have got evidence of harm. The evidence that paracetamol is harmful is not strong but observations in humans regarding possible developmental issues are supported by animal studies.
“It is always important to take medication in pregnancy with specialist advice. A good principle is to only use medications with a proven track record of both efficacy and safety. Paracetamol is one of those drugs that can be safely used.
“The baby is fully formed by 10 weeks of pregnancy and it is unlikely a drug will cause significant harm in fetal development after this point.
“Prudent surveillance and more research should continue but paracetamol can be used to treat pain and fevers in pregnancy.”
Dr Sarah Stock, Reader and Consultant Maternal and Fetal Medicine, University of Edinburgh Usher Institute, said: “This paper doesn’t change recommendations on paracetamol use in pregnancy.
“The team have done a good job of bringing together existing evidence, but unfortunately, much of that evidence is not robust enough to draw any conclusions that paracetamol use in pregnancy, especially occasional use, causes developmental problems in humans.
“Paracetamol is effective at reducing pain and fever, and so continues to be an important medicine that pregnant people should use if needed.
“Of course, pregnant or not, no-one should take a medication unnecessarily, for longer than necessary or at a higher dose than needed.
“There is no new data in this publication — it is a summary of previous studies. The authors rightly lobby for more good quality research, as based on current evidence from previously-published studies it is impossible to disentangle whether it is conditions that cause people to take paracetamol at high doses for long periods of time, or paracetamol itself, that might have a link to developmental problems.”