Women exposed to a chemical used in hospital disinfectants are more likely to give birth to babies with shrunken heads, scientists say.
So-called ethylene oxide is also found in antifreeze, detergents and the liquid used in lateral flow Covid tests, according to the government.
It can also be found in cigarette smoke. However, Spanish researchers have discovered that exposure during pregnancy can cause newborns to be born with a lower weight and a slightly shrunken head.
A study involving just over 1,000 newborns, including some in the United Kingdom, found evidence of ethylene oxide in umbilical cord blood, the blood that remains in the placenta and umbilical cord after birth.
Women with the highest levels of ethylene oxide had, on average, babies who were 71 g lighter and had a head circumference 0.3 cm smaller.
Women exposed to a common hospital disinfectant also used in Covid testing are more likely to give birth to children with shrunken heads, scientists say
Official UK advice on ethylene oxide states that trace amounts in medical devices, including Covid lateral flow tests, are not expected to harm an unborn child.
Lead author Barbara Harding, from the Barcelona Institute for Global Health, said: “Reduced head circumference has been linked to delayed neurodevelopment, and reduced birth weight increases the risk of cardiovascular disease, type 2 diabetes mellitus and osteoporosis.”
On the other hand, low birth weight is associated with a higher risk of infant mortality, developmental problems and poorer overall health in old age, according to the NHS.
The authors, who published their findings in the journal Epidemiologysaid that the highest levels of ethylene oxide were found in female smokers.
However, they warned that women are also exposed to the chemical through indoor contamination from various household products, such as cleaning and personal care brands.
Women who came into contact with ethylene oxide in healthcare settings where it was used for sterilization were also at increased risk, they added.
The researchers did not look at how much environmental exposure it would take to cause problems, and there is no indication that normal use of cleaning products can cause birth defects.
The study examined cord blood from a total of 1,106 newborns from Greece, Spain, Norway, the United Kingdom and Denmark.
Manolis Kogevinas, lead author of the study, said it highlights the importance of minimising exposure to ethylene oxide (EO) at home and in the workplace.
“The study results highlight the importance of addressing EO exposure in both occupational and non-occupational settings,” he said.
“Policy changes to reduce EO exposure in vulnerable populations, such as women of childbearing age, could protect fetal health and improve birth outcomes.”
Ethylene oxide has previously been linked to poor birth outcomes and some studies suggest it could be “toxic” to the reproductive system.
Official UK advice on ethylene oxide states that trace amounts of ethylene oxide in medical devices, including Covid lateral flow tests, are not expected to harm the unborn child.