Here are answers to some of the most common questions pregnant patients ask, provided by the Pregnancy Committee of the American College of Allergy and Immunology:
Can allergy medications safely be used during pregnancy?
Antihistamines may be useful during pregnancy to treat the nasal and eye symptoms of seasonal or perennial allergic rhinitis, allergic conjunctivitis, the itching of urticaria (hives) or eczema, and as an adjunct to the treatment of serious allergic reactions, including anaphylaxis (allergic shock). With the exception of life-threatening anaphylaxis, the benefits from their use must be weighed against any risk to the fetus. Because symptoms may be of such severity to affect maternal eating, sleeping or emotional well-being, and because uncontrolled rhinitis may pre-dispose to sinusitis or may worsen asthma, antihistamines may provide definite benefit during pregnancy.
Chlorpheniramine (ChlorTrimeton®), and diphenhydramine (Benadryl®) have been used for many years during pregnancy with reassuring animal studies. Generally, chlorpheniramine would be the preferred choice, but a major drawback of these medications is drowsiness and performance impairment in some patients.. Two of the newer less sedating antihistamines loratadine (Claritin®), and cetirizine (Zyrtec®) have reassuring animal and human study data and are currently recommended when indicated for use during pregnancy.
The use of decongestants is more problematic. The nasal spray oxymetazoline (Afrin®, Neo-Synephrine® Long-Acting, etc.) appears to be the safest product because there is minimal, if any, absorption into the blood stream. However, these and other over-the-counter nasal sprays can cause rebound congestion and actually worsen the condition for which they are used. Their use is generally limited to very intermittent use or regular use for only three consecutive days.
Although pseudophedrine (Sudafed®) has been used for years, and studies have been reassuring, there have been recent reports of a slight increase in abdominal wall defects in newborns. Use of decongestants during the first trimester should only be entertained after consideration of the severity of maternal symptoms unrelieved by other medications. Phenylephrine and phenylpropanolamine are less desirable than pseudophedrine based on the information available.
A corticosteroid nasal spray should be considered in any patient whose allergic nasal symptoms are more than mild and last for more than a few days. These medications prevent symptoms and lessen the need for oral medications. There are few specific data regarding the safety of intranasal corticosteroids during pregnancy. However, based on the data for the same medications used in an inhaled form (for asthma), budesonide (Rhinocort®) would be considered the intranasal corticosteroid of choice, but other intranasal corticosteroids could be continued if they were providing effective control prior to pregnancy.
Immunotherapy and influenza vaccine
Allergen immunotherapy (allergy shots) is often effective for those patients in whom symptoms persist despite optimal environmental control and proper drug therapy. Allergen immunotherapy can be carefully continued during pregnancy in patients who are benefiting and not experiencing adverse reactions. Due to the greater risk of anaphylaxis with increasing doses of immunotherapy and a delay of several months before it becomes effective, it is generally recommended that this therapy not be started during pregnancy.
Patients receiving immunotherapy during pregnancy should be carefully evaluated. It may be appropriate to lower the dosage in order to further reduce the chance of an allergic reaction to the injections.
Influenza (flu) vaccine is recommended for all patients with moderate and severe asthma. There is no evidence of associated risk to the mother or fetus.
Should I continue my allergy shots during pregnancy?
It is appropriate to continue allergy shots during pregnancy in women who are not having reactions to the shots, because they may lessen your allergic or asthma symptoms. There is no evidence that they have any influence on preventing allergies in the newborn. It is not generally recommended that allergy shots be started during pregnancy.
To summarize: It is extremely important to monitor closely any asthma or allergic problems during your pregnancy. In the vast majority of cases, you and your child can look forward to a good outcome, even if your asthma is severe, so long as you follow your doctor's instructions carefully. At the very first signs of breathing difficulty, call your doctor.
Remember the danger of providing an inadequate supply of oxygen to your baby is a much greater risk than taking the commonly used asthma medications.