Exposure to paracetamol during pregnancy could reduce female fertility. Studies on rats and mice have shown that the drug can disrupt the reproductive development of females, which has an impact on egg reserves and fertility in adulthood.
As one of the most used and prescribed painkillers in the world, this study could have a huge impact on recommendations for pregnant women if the same effects are observed in humans. While the effect may not be severe (and may not result in complete infertility), three different studies all independently found that paracetamol does have an effect.
Currently, doctors recommend that women use paracetamol for the shortest duration necessary to relieve pain – this recommendation still stands until further evidence is available.
The effect is seen in female but not male reproduction because females are born with a finite number of eggs. When a female is born with a reduced number of eggs, there are fewer available for fertilisation which will reduce their chances of pregnancy (especially later in life).
While there are parallels between rodent and human development, it is important to investigate the matter further before changing guidance given to pregnant women. Finding a link in humans may prove to be more challenging, as fertility problems are not observed until mid to late adulthood. In the meantime, further studies are likely to see whether there is a definite causal connection and explain the mechanism behind the reduction.
It is important that pregnant women are able to properly treat any pain without risk to themselves or their children. Pregnant women are always advised to consult with their doctor or pharmacist if they are in pain to ensure that they are taking the right medication and dose for their condition.