Advice from the Royal College of Obstetricians and Gynaecologists (RCOG) has provoked concern, with critics saying the report is alarmist and can add to a mother's stress.
Tracey Brown, from Sense About Science, said the warning could cause more harm than good.
Pregnancy is a time when people spend a lot of time and money trying to work out which advice to follow, and which products to buy or avoid. The simple question parents want answered during pregnancy is, 'Should we be worried?'.
What we need is help in navigating these debates about chemicals and pregnancy. Disappointingly, the RCOG report has ducked this.
As the report itself shows, there are many unfounded rumours about links between particular substances and pregnancy outcomes.
Pregnant women are being advised to avoid chemicals in household products such as food packaging, cosmetics and family medicines that could cause harm to their unborn babies.
The Royal College of Obstetricians and Gynaecologists says women should be made aware of the sources of chemicals to minimise the possibility of harm during pregnancy.
It has urged them to "play it safe", despite uncertainty about chemicals' effects and the surrounding risks.
But the report's authors admit there is little evidence to suggest whether such chemicals do affect a baby's development, or even if there is a risk to health. However, they advise women to assume that a risk is present.