A study led by the MRC Centre for Reproductive
Health at the University of Edinburgh and published
in the journal Scientific Reports, has found using
painkillers in pregnancy may reduce fertility in
subsequent generations.
Tests in rats found that when a mother was given
painkillers during pregnancy, her female offspring
had fewer eggs, smaller ovaries and smaller litters
of babies than those not exposed to the drugs.
Exposed male offspring were also found to be
affected at birth – showing smaller numbers of cells
that give rise to sperm in later life. However,
their reproductive function recovered to normal
levels by the time they reached adulthood.
Researchers say the findings are significant given
the similarities between the reproductive systems of
rats and humans, although it is difficult to
directly extrapolate these results to pregnant
women.
The team recommends that pregnant women should stick
with current guidelines to use painkillers at the
lowest possible dose, for the shortest possible
time.
Scientists tested the effects of two painkillers in
pregnant rats – paracetamol and a prescription-only
painkiller called indomethacin, which belongs to the
same class of drugs as ibuprofen and aspirin.
Rats were given the drugs over the course of several
days – four days for indomethacin or nine days for
paracetamol. The effects of the drugs were seen
within one to four days of the start of treatment.
Scientists say that because the pace of foetal
development in humans is slower than it is in rats,
it is hard to say from this study how this would
translate in human use.
In addition to affecting a mother’s immediate
offspring, the study showed that painkillers taken
in pregnancy also affected the subsequent generation
of rats.
The team found that the resulting females – the
granddaughters of the mother given painkillers in
pregnancy – also had reduced ovary size and altered
reproductive function.
Scientists say the results suggest that some
painkillers may affect the development of the cells
that give rise to eggs and sperm - called germ cells
- while a foetus is in the womb.
This may be because the painkillers act on hormones
called prostaglandins. These are known to regulate
female reproduction and control ovulation, the
menstrual cycle and the induction of labour.
Professor Richard Sharpe, who co-led the study at
the MRC University of Edinburgh Centre for
Reproductive Health, said the results follow
previous research that indicates painkillers should
be used with caution during pregnancy.
He said: “It’s important to remember that this study
was conducted in rats not humans, however, there are
many similarities between the two reproductive
systems. We now need to understand how these drugs
affect a baby’s reproductive development in the womb
so that we can further understand their full
effect.”
Professor Richard Anderson, Elsie Inglis Professor
of Clinical Reproductive Science, who co-led the
study, said: “These studies involved the use of
painkillers over a relatively long period. We now
need to explore whether a shorter dose would have a
similar effect, and how this information can be
usefully translated to human use.”
For more information
Analgesic exposure in pregnant rats affects fetal
germ cell development with inter-generational
reproductive consequences
Link...
Medical Research Council MRC
Link...
MDN |