Taking paracetamol during pregnancy may impair the future fertility of female offspring, according to a study published in the UK.
The drug is a widely used,over-the-counter treatment for pain relief and fever reduction, and is commonly taken by pregnant women.
Recent studies have linked paracetamol use during pregnancy with disruptions in the development of the male reproductive system, but the effects on female offspring had not yet been investigated.
The article on the possible female fertility risk was published by the Society for Endocrinology on Saturday in its research journal Endocrine Connections.
It reviews three separate studies in rodents that all report altered development in the reproductive systems of female offspring from mothers given paracetamol during pregnancy, which may impair their fertility in adulthood.
Exposure to some chemicals during pregnancy can cause developmental effects that may not manifest until much later in life. In rodents and humans females are born with a finite number of eggs for reproduction in the future. In these reviewed studies rodents given paracetamol during pregnancy, at doses equivalent to those that a pregnant woman may take for pain relief, produced female offspring with fewer eggs.
This meant that in adulthood they had fewer eggs available for fertilisation, which may reduce their chances of successful reproduction, particularly as they get older.
Further investigation
Dr David Kristensen and colleagues from Copenhagen University Hospital reviewed the findings.
“Although this may not be a severe impairment to fertility it is still of real concern since data from three different labs all independently found that paracetamol may disrupt female reproductive development in this way, which indicates further investigation is needed to establish how this affects human fertility,” he said.
The medical director at Beacon CARE Fertility in Co Dublin, Dr Ahmed Omar, said the findings from the Copenhagen study were "very interesting and concerning".
“However we should be very cautious in interpreting findings from animal studies in humans. These findings should encourage similar studies in humans to see if these observations are replicated.”
He said current advice for pregnant women was to “avoid taking any medication during pregnancy unless it is clinically indicated, and that the benefit of such drugs clearly outweigh any perceived risks to the unborn child”.
Human studies
Dr Kristensen said establishing a link between paracetamol taken by mothers during pregnancy and fertility problems much later in the adult life of the child would be difficult. He said an inter-disciplinary approach was needed.
“By combining epidemiological data from human studies with more experimental research on models, such as rodents, it may be possible to firmly establish this link and determine how it happens, so that pregnant women in pain can be successfully treated without risk to their unborn children.”
On the issue of medical advice, Dr Kristensen said: “As scientists we are not in the position to make any medical recommendations, and we would urge pregnant women in pain to consult with their GP, midwife or pharmacist for professional advice.”
