Painkillers in pregnancy may affect babies' future fertility

Edinburgh University found the drugs may also affect the fertility of future generations, by leaving marks on DNA.

Experts said the findings added to growing evidence some medicines, including Paracetamol, should be used with caution during pregnancy.

Researchers stressed advice for pregnant women remained unchanged.

Current guidelines say, if necessary, Paracetamol should be used at the lowest possible dose for the shortest possible time. Ibuprofen should be avoided during pregnancy.

The study looked at the effects of Paracetamol and ibuprofen on samples of human foetal testes and ovaries.

Tissue samples

The scientists found similar effects using several different experimental approaches, including lab tests on human tissue samples and animal studies.

Human tissue exposed to either drug for one week in a dish had reduced numbers of germ cells that give rise to sperm and eggs, cells, the study found.

Ovaries exposed to Paracetamol for one week had more than 40% fewer egg-producing cells. After ibuprofen exposure, the number of cells was almost halved.

Experts said this was important because girls produce all of their eggs in the womb, so if they are born with a reduced number it could lead to an early menopause.

Painkiller exposure during development could have effects on unborn boys too, the study found.

Testicular tissue exposed to painkillers in a culture dish had around a quarter fewer sperm-producing cells after exposure to Paracetamol or ibuprofen.

The team also tested the effects of painkiller treatment on mice that carried grafts of human foetal testicular tissue.

The grafts have been shown to mimic how the testes grow and function during development in the womb.

Female offspring

After just one day of treatment with a human-equivalent dose of Paracetamol, the number of sperm-producing cells in the graft tissue had dropped by 17%. After a week of drug treatment, there were almost one third fewer cells.

Previous studies with rats have shown that painkillers administered in pregnancy led to a reduction in germ cells in female offspring. This affected their fertility and the fertility of females in subsequent generations.

The scientists found that exposure to Paracetamol or ibuprofen triggered mechanisms in the cell that made changes in the structure of DNA, called epigenetic marks.

The marks can be inherited, helping to explain how the effects of painkillers on fertility may be passed on to future generations. 

Painkillers' effects on germ cells are likely caused by their actions on molecules called prostaglandins, which have key functions in the ovaries and testes, the researchers found.

The study, published in Environmental Health Perspectives, was funded by the Medical Research Council, Wellcome and the British Society of Paediatric Endocrinology and Diabetes.

Dr Rod Mitchell, who led the research at the University of Edinburgh's MRC Centre for Reproductive Health, said: "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."

 

Your Pollen Survival Guide

Springtime brings not just deliciously longer days, warmer weather, balmy breezes and blooming flowers. For people with allergies, it means the return of pollen. Pollen and allergies don't mix.

There's not much you can do to avoid pollen altogether -- after all, it's produced by grasses, trees, flowers and weeds -- but you can minimize the misery. Here's your springtime pollen survival guide.

Can You Really Avoid Pollen?

Be realistic. "Complete avoidance of pollen is impractical," says Daniel Waggoner, MD, an allergist in Mystic, Conn., tells his patients. "In Connecticut, spring brings tree pollens. Late spring and summer brings grass pollens. Late summer and fall brings weed pollen."

"That in general holds true across the country," he says. However, if you travel south, some types of pollen may linger year round, with the warmer temperatures.

But there's a lot you can do to minimize the fallout from pollen -- from simple measures you can take around the house to seeing an allergist for treatment.

First, Know Your Pollen Count

Pollen is the invisible annoyance. The average pollen particle is smaller than the width of an average human hair, according to the American Academy of Allergy Asthma & Immunology.

But once pollen reaches your nose and throat, it can trigger an allergic reaction if you are the sensitive type. And about 35 million Americans are sensitive to pollen, according to National Institutes of Health estimates.

It's easy enough to check the pollen count in your locale through the National Allergy Bureau, a section of the American Academy of Allergy Asthma and Immunology, which maintains an online site for pollen counts.

Pollen counts calculate a given pollen in a specific amount of air during a particular period, such as 24 hours, according to the Asthma and Allergy Foundation of America.

Ask your allergist exactly what you are allergic to, and when that pollen peaks, so you can be ready to take action before the pollen triggers bad allergic reactions, says Russell B. Leftwich, MD, an allergist in Nashville, Tenn.

Second, Stay Indoors When Pollen Counts Are High

When pollen counts are high, shut the windows and use the air conditioner, suggests Leftwich.

"The biggest problem pollen-sensitive patients have are the times when the pollen is heaviest and outside temperatures are the nicest," he says. "People are tempted to sleep with the windows open."

Big mistake, he tells them. "Normally with the windows shut and the air conditioner on there is very little pollen in your house."

Third, Plan Outdoor Time Wisely

It's best to avoid the outdoors during high pollen counts, but that's not always practical.

"Most plants pollinate from 5 a.m. to 9 a.m., says Miguel P. Wolbert, MD, an allergist in Evansville, Ind. Wolbert is certified in pollen counting for the National Allergy Bureau. "If you are outside then, going for a jog, you pick up the pollen on your hair, face, and clothes," he says.

Windy days can be worse than calm days. "Windy days stir the pollen around," he says.

If a dog is jogging with you, he's a pollen-carrier, too, Wolbert says. "Often people blame the dog for an allergy, and it might be the pollen on the pet."

When possible, avoid early morning outings with the dog on high pollen days, especially if it's windy.

Fourth, Protect Yourself From Pollen When You Go Outdoors

"When people do have to be outside at a high pollen time, wearing a mask is a good filter," says Leftwich. He suggests getting a painter's mask at your local hardware store or home improvement center.

"If you have bad pollen allergies and you are the one who has to do the yard work, wearing a mask is a good idea," he says. They don't look fashionable, he admits, but reminds his patients: "It's not a social occasion."

When you're outside, minimize your exposure to pollutants and other allergens as well, suggests Wolbert. If you go jogging later in the day when pollen tends to die down, pick a residential street instead of a thoroughfare to avoid car exhaust.

Also, adds Leftwich: "Take your allergy medicines before you go outside. People wait until they are miserable and then take it. For some reason they think [an allergy attack] is not going to happen this time."

Fifth, Keep Pollen From Following You Into the House

As soon as you arrive home -- even if you've just been in the backyard -- change your clothes and take a shower to rid your body of as much pollen as possible, Leftwich says.

Don't forget your hair, especially if it is long, Leftwich says. "Just rinsing your hair would do."

Sixth, Treat Your Pollen Allergies

A variety of over-the-counter and prescription medications can help your allergy symptoms such as runny nose, itchy eyes, congestion, and coughing.

Get an evaluation from an allergist to help find the best allergy remedy for you, Wolbert says. The doctor may recommend an antihistamine, other allergy pills, inhaled allergy treatments, or even allergy shots.

Beware of overusing decongestant nasal sprays. Using decongestant sprays for more than three days in a row, he says, can lead to a "rebound" effect. Your allergy symptoms may become worse than before you started the medicine.

If your pollen allergies are bad, talk to your doctor about preventive treatment with antihistamines or inhaled steroids. Start taking the treatment before pollen season starts.

You might also consider allergy shots (allergy immunotherapy) if you suffer severe allergies. The doctor injects a small amount of the allergen that affects you, building up your immunity over time. Typically, the injection is given once a week or once a month. "It usually takes three to five years of allergy shots," Wolbert says, to build up immunity to the allergen.

"Most people get good results, if they stick with the recommended number of injections," he says.

Seventh, Take an Allergy Vacation

If pollen still drags you down after taking all the six steps above, consider taking an allergy vacation.

When pollen season is in full swing, take a trip to an area less affected by pollen, such as the beach or the seashore nearest to your hometown. Relax! You deserve it.