Allergies and Pregnancy

Pregnancy Changes Affect Allergies

Without a doubt, pregnancy puts a great deal of strain on a woman's body. Breathing becomes labored for a variety of physiological reasons, not the least of which is the added weight around the belly. A growing abdomen complicates the problem by pushing up on the diaphragm so that a woman's breathing becomes shallow and she tends to breathe faster.

To compensate for the labored breathing, pregnant women tend to breathe more through their mouths instead of their noses, meaning that more air passes into the body without the benefit of the nose's filtration system. The nasal passages swell and narrow during pregnancy in response to certain hormones.

Chemical changes affect a pregnant woman's response to allergies as well. For instance, increased hormone levels and changes in the immune system make it more difficult to combat the flu and other illnesses, explains Dr. Gluck. So, if a woman is already prone to allergies, her weakened immune system may react to irritants more strongly than it would normally.

Preventing Allergies

"Overall there are two approaches to avoid triggering factors with allergies in pregnancy," says Dr. Michael Schatz, MD, president of the American Academy of Allergy, Asthma and Immunology and chief of the Department of Allergy at Kaiser Permanente in San Diego. First, he advises pregnant women avoid their known allergy triggers, whatever they may be. For Daniel that meant encasing her mattresses in special covers that minimize dust-mite exposure, throwing out old pillows in favor of new ones, and using an air purifier throughout her pregnancy.

The second approach is to steer clear of smoking, chemical fumes, and other non-specific irritants, in an effort to lessen allergy symptoms.

Treating Allergies

"Allergy medications are much safer than most women think," says Dr. Schatz, explaining that any over-the-counter and prescription allergy and asthma medications, especially topical nasal sprays and antihistamines, have a long, safe track record in helping a pregnant woman have a more comfortable pregnancy while not affecting the unborn baby.

"You don't want to use any medication if you don't need to during pregnancy," advises Dr. Gluck. "However you need to weigh the potential benefits to the patient versus the risks." Untreated allergies can lead to more serious allergic reactions such as asthma, even in women who have never had symptoms previously.

Dr. Gluck cautions pregnant women to work closely with their doctors or midwives and their allergists to come up with a treatment plan. For example, if a woman went off her allergy medication regimen once she became pregnant, assuming it was harmful for her baby, she might actually put her baby at greater risk. Labored breathing from pregnancy and allergies may lead to higher blood pressure, which can in turn cause preeclampsia (pregnancy-induced hypertension) or preterm labor. Allergy symptoms may also affect the flow of oxygen to the baby—if the woman has difficulty drawing in breath, the baby may not receive the oxygen he or she needs to develop properly.