of mild painkillers such as paracetamol, aspirin and ibuprofen during pregnancy
may partly account for a sharp increase in male reproductive disorders in
recent decades, according to a study published on Monday.
research found that women who took a combination of more than one mild analgesic
during pregnancy had an increased risk of giving birth to sons with undescended
testicles. This condition, called cryptorchidism, is known to be a risk
factor for poor semen quality and a greater risk of testicular cancer in
researchers from Finland, Denmark and France, whose work was published in
the Human Reproduction journal, said more studies were urgently needed and
advice to pregnant women on use of painkillers should be reconsidered. "Women
may want to try to reduce their analgesic use during pregnancy," said
Henrik Leffers of Copenhagen's Rigshospitalet, who led the research. "However,
as biologists this is not something we can advise women about. So we recommend
that pregnant women seek advice from their physician."
to the Leffers team, more than half of pregnant women in Western countries
report taking mild analgesics. Doctors generally say women should avoid
taking medicines while pregnant, but that paracetamol, ibuprofen and aspirin
are considered safe in some conditions and at certain times.
has been found to affect as many as one in 11 Scandinavian boys, although
rates vary from two to nine percent in various Scandinavian countries.
researchers said several studies have shown a global decline in sperm counts,
although other studies have contradicted this finding and researchers do
not agree on whether there is a measurable change globally. This study looked
at two groups of women, 834 in Denmark and 1,463 in Finland, who were questioned
about their use of medication during pregnancy.
male babies were examined at birth for any signs of cryptorchidism, ranging
from a mild form of the condition in which the testis is located high in
the scrotum to the more severe form, in which the testis is high up in the
study was backed by work by scientists in Denmark and France who studied
rats and found that analgesics led to insufficient supplies of the male
hormone testosterone during a crucial period of gestation when the male
organs are forming.
researchers said the effect of analgesics on rats was comparable with that
caused by similar doses of known hormone, or endocrine, disrupters such
as phthalates -- a family of chemicals used in the manufacture of plastics
such as PVC. The results of the human study showed that women who used more
than one painkiller simultaneously had a seven-fold increased risk of giving
birth to sons with some form of cryptorchidism compared with women who took
nothing. The second
trimester appeared to be a particularly sensitive time, with simultaneous
use of more than one painkiller during this period linked to a 16-fold increase
we should be cautious ... the use of mild analgesics constitutes by far
the largest exposure to endocrine disruptors among pregnant women, and use
of these compounds is at present the best suggestion for an exposure that
can affect a large proportion of the human population," Leffers said.
experts said the findings were striking but should be interpreted with caution:
"This study adds to the body of evidence about the effect of medicines
on fetal development. However, due to study limitations, further research
is needed to draw firm conclusions about the effect of painkillers on male
fertility," said Neal Patel of the Royal Pharmaceutical Society.
Pacey of Britain's Sheffield University said the findings were "somewhat
is worth noting the researchers found a significant difference when women
had used painkillers for two weeks or more and that the impact was greatest
when taking them during their second trimester. Clearly further research
is needed as a matter of priority," he said in an emailed comment.