10/13/2013 8:05 pm
The first trimester of pregnancy is so important in development of the baby, and the effect of medications is always a concern to our patients. A recent study in American Journal of Epidemiology 2013 (Vol 178 No. 2 p. 198-208) entitled "Use of Decongestants During Pregnancy and Risk of Birth Defects" showed that the first trimester use of the decongestants may be associated with fetal birth defects in a small number of the exposed pregnancies. The chances of these medications, which are so commonly used in women who do not even know they are pregnant, causing a birth defect are very small. In order to decrease this risk, we are recommending women avoid the use of decongestants until after 12 weeks gestation. Decongestents include the generic names phenylephrine, phenylpropanolamine and psuedoephedrine. Oxymetazoline should be avoided in the first and second trimesters. Yeast medication ending ending in azoles should be avoided in the first trimester.
We are not talkng about a large increase in the risks. The risks were all much less that one percent or less than one of one hundred exposed pregnancies. More studies are needed. Specific risks are that the phenylephrine are associated with fetal heart or endocardial cushion defects. The baseline risk of an endocardial cushion defect is 0.34 per 1000 live births. The increase in risk is 2.7 per 1000 live births or 0.27%. Phenylpropanolamine in the first trimester is associated with slight increase in pyloric stenosis. There are very rare associations with the first trimester use of pseudoephedrine and limb reduction defects.
Oxymetazoline or Afrin nasal spray should be avoided in the first and second trimester due to concerns about effects of the fetal kidneys, specifically the renal collecting system.
The imidazoles are used for treatment of yeast or fungal infections and include clotrimazole, miconazole, ketaconazole, and fluconazole. The use of these drugs in the first trimester is being investigated and is thought to be associated with the extremely rare birth defect of tracheo-esophageal fistula. We are recommending avoiding the the treatment of yeast infections with these medication.
All this new information just reminds us that pregnancy outcomes are usually good, but we are wise to consider carefully any medications we take including over the counter drugs. Acetaminophen or Tylenol was not associated with any problems.