People usually rush for over-the-counter drugs to deal with pains such as headaches or muscle and joint ailments.
But while health effects of such medicines may be minimal in adults, researchers warn that mothers who take high amounts of painkillers during pregnancy risk endangering the health of their babies and future generations.
New research, published in the Environmental Health Perspectives journal, shows that the drugs could affect the fertility of unborn children in later life.
The medicines may also distort the DNA or genes of these children thus causing them to transfer the fertility problems to future generations.
They do this by triggering mechanisms in the cell (known as epigenetic marks) that make changes in the structure of DNA. Subsequent generations that inherit the marks end up with fertility challenges.
The researchers note that common pain killers like Paracetamol and Ibuprofen should be used with caution during pregnancy.
During the study, scientists from the University of Edinburgh assessed the impact of the two drugs on tissue samples drawn from the testicles and ovaries of unborn male and female foetuses.
Tissue exposed to either of the drugs for a week had a reduced number of germ cells which usually give rise to sperms and eggs that are responsible for people’s fertility or their ability to have children. The ovaries had more than 40 per cent fewer egg-producing cells when exposed to paracetamol.
But after ibuprofen exposure, the number of cells was almost halved.
Such reductions are detrimental for girls as they produce all their eggs while still in their mother’s womb.
In normal circumstances, baby girls usually have about a million eggs at birth. But at puberty only about 300,000 remain.
Thereafter, a huge proportion is shed monthly when women have their periods until they are depleted from the age of 50 when women hit menopause.
Therefore, being born with fewer eggs could lead to early menopause, thus making conception elusive for otherwise young women. The ability of women to have children decreases as they age due to the deteriorating number and quality of eggs.
For unborn boys, the study found that the painkillers led them to have 25 percent fewer sperm producing cells.
Having low sperm counts is a major cause of male infertility. This is because a man usually has to produce millions of sperms so as to enhance chances of just one lucky one fertilising an egg.
“We would encourage women to think carefully before taking painkillers in pregnancy and to follow existing guidelines — taking the lowest possible dose for the shortest time possible,” said Rod Mitchell, lead author of the study from the University of Edinburgh’s MRC Centre for Reproductive Health.
Nelly Bosire, a Nairobi based consultant gynaecologist, noted that all medications should be minimised or avoided during pregnancy unless the benefits of taking them outweigh risks.
Dr Bosire said that effects of most drugs on pregnancy are still largely unknown since research testing efficacy and side effects of new medicines usually involves people other than pregnant women.
“This is because no one would like to subject mothers to something that could endanger their life or that of their babies.” Dr Bosire said that in most cases, women attempt to withstand pain felt during pregnancy so as to avoid taking any medication that may harm the unborn child.
“This is a period when most women go to hospital even when they have less serious infections like flu instead of rushing to buy drugs first,” she said.
Even those seeking over-the-counter medication, she said, usually expect the person dispensing the drugs to guide them on the right kind of medicine for pregnant women.
“But you know most of our pharmacies aren’t necessarily run by pharmacists. So the cashiers or those masquerading as experts can mislead women and end up endangering the life of the unborn child.
“Different painkillers have different effects at different times of pregnancy. That’s why it’s important to check with the doctor before taking any drugs during pregnancy.”
For pain relief, paracetamol (used in moderation) is recommended as a safer choice compared to ibuprofen.
This is because taking ibuprofen or other nonsteroidal anti-inflammatory drugs in the last few weeks of pregnancy has been linked to low levels of amniotic fluid which can cause problems with how the baby grows and how well the lungs develop.
If volumes of the fluid decrease during the first trimester of pregnancy, and the early part of the second trimester, then the risk of miscarriage will increase.
And in the most serious cases, low amniotic fluid can also cause a baby to be stillborn.
There are also concerns that some medications may delay or prolong labour.
And if used within a week of delivery, they heighten bleeding risk which is life threatening for both the mother and her child.