Taking paracetamol during pregnancy may reduce fertility of daughters

Exposure to paracetamol during pregnancy may reduce the fertility of female offspring, suggests research in rats and mice.

Dr David Kristensen at Copenhagen University Hospital in Denmark and colleagues, reviewed three recent studies on the effects of paracetamol administration during pregnancy in rats and mice. All three studies found evidence for disrupted reproductive development of female offspring, including a lower number of eggs and reduced fertility in adulthood. The review was published in Endocrine Connections.

This may be a cause for concern as paracetamol is a commonly prescribed painkiller worldwide. Previous studies have already highlighted the risks associated with exposure to chemicals during pregnancy, including a link between prenatal exposure to analgesics and reduced fertility in male offspring (see BioNews 584), however studies on females had been lacking. Females, unlike males, are born with a set number of gametes. This means that any disruption during the development may be damaging to their future fertility.

'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,' said Dr Kristensen. He added that further investigation was needed to establish any effects on human fertility.

Despite similarities between rodent and human reproductive systems, it is difficult to know to what extent these findings are relevant to human pregnancies. The dosage and length of paracetamol administration in these studies may not be representative of a typical use of painkillers in pregnant women; in two of the studies the dose was much higher than the standard recommendation, and the drugs were given for a relatively high proportion of the pregnancy duration.

Short-term use of paracetamol is currently considered safe during pregnancy. 'Current recommendations regarding paracetamol use for the shortest duration necessary to relieve pain during pregnancy should not change on the basis of this review article,' said Dr Rod Mitchell, consultant paediatric endocrinologist at the University of Edinburgh.

However, 'further research, including laboratory experiments using human tissues or large population-based studies looking at adults exposed to paracetamol in-utero, is required to determine whether paracetamol exposure during pregnancy can adversely affect fertility in humans', he added.