Claritin is a brand name of the medication loratidine, an over-the-counter antihistamine. It is used to treat symptoms of seasonal allergies, such as runny nose, sneezing, watery eyes and a scratchy throat. Claritin is often preferred over other antihistamines because it does not usually cause drowsiness. As with many medications, however, questions have been raised about whether Claritin is safe to use during pregnancy.
Possible Birth Defect Link
Concerns about the safety of Claritin during pregnancy first appeared when a study published in the January 2001 issue of the "International Journal of Risk and Safety in Medicine" reported that boy babies born to women who took loratadine during pregnancy had an increased risk of a birth defect called hypospadias. With this condition, which occurs almost exclusively in males, the opening of the tube that carries urine -- the urethra -- is not in its normal location. Instead, the opening is located anywhere from the head of the penis to the scrotum.
Animal Studies Inconclusive
Studies in animal models have tried to explain how loratadine might cause hypospadias, but the results have not been consistent. In one study published in the November 2003 issue of "Reproductive Toxicology," large doses of loratadine -- up to 26 times what a human would take -- did not lead to any abnormalities in the reproductive organs in the male offspring of pregnant rats. In contrast, a study published in the February 2006 issue of the "Journal of Urology" found that the male offspring of pregnant mice that were given loratadine developed hypospadias along with changes in certain gene pathways that may play a role in the normal development of male reproductive tissues.
In contrast to the results reported in earlier human and animals studies, more recent studies have not shown an increased risk of major birth defects in infants of women who took loratadine during pregnancy. In fact, in the June 2006 issue of "International Journal of Risk and Safety in Medicine," the same authors who reported an increased risk of hypospadias with loratadine in 2001 found that the risk was not increased when they included more pregnant women who had taken loratadine in their analysis. Further, a review published in the February 2008 issue of "Drug Safety" -- in which the authors combined results from eight studies that evaluated a total of 453,107 infants whose mothers took loratadine while pregnant -- also found no increased risk of hypospadias.
Pregnancy Complications Considered
Women taking loratadine during the first 3 months of pregnancy do not show any difference in rates of stillbirth, time of delivery or birth weight when compared to women who do not take loratadine, or those who take other antihistamines. However, in one study of 210 women published in the June 2003 issue of the "Journal of Allergy and Clinical Immunology," participants taking loratadine had a higher rate of miscarriage. The researchers point out, however, that the higher miscarriage rate may have been due to the fact that women who took loratadine tended to be older and were at an earlier stage of pregnancy. They explain that these factors -- both of which are associated with an increased risk of miscarriage -- rather than taking loratadine may account for the higher rate of miscarriage.
According to the American Academy of Pediatrics, loratadine is compatible with breastfeeding because less than 1 percent of the mother's dose gets into the breastmilk -- an amount that is considered too small to lead to any problems with the baby. Breastfeeding mothers should consider taking their medication after breastfeeding and use the lowest possible effective dose.
It is important to remember that with each pregnancy, the risk of birth defects in the U.S. is approximately 3 percent, according to the Centers for Disease Control and Prevention -- even if the mother is not taking medications.
Talk with your doctor before taking any new medications while pregnant or if you have concerns about medicines you are already taking.
Is This an Emergency?
- International Journal of Risk and Safety in Medicine: Monitoring of Maternal Drug Use and Infant Congenital Malformations. Does Loratadine Cause Hypospadias?
- Reproductive Toxicology: Effects of Perinatal Loratadine Exposure on Male Rat Reproductive Organ Development
- Journal of Urology: Loratadine Exerts Estrogen-like Effects and Disrupts Penile Development in The Mouse
- International Journal of Risk and Safety in Medicine: No Increased Risk of Infant Hypospadias After Maternal Use of Loratadine In Early Pregnancy
- Drug Safety: Risk of Hypospadias in Offspring of Women Using Loratadine During Pregnancy: A Systematic Review and Meta-Analysis
- Journal of Allergy and Clinical Immunology: Fetal Safety of Loratadine Use In The First Trimester of Pregnancy: A Multicenter Study
- Journal of Allergy and Clinical Immunology:Pregnancy Outcome After Gestational Exposure to Loratidine or Antihistamines: A Prospective Controlled Cohort Study
- Pediatrics: The Transfer of Drugs and Other Chemicals Into Human Milk
- March of Dimes Global Report on Birth Defects: The Hidden Toll of Dying and Disabled Children
- Centers for Disease Control and Prevention: Key Findings: Updated National Birth Prevalence Estimates for Selected Birth Defects in the United States, 2004-2006
- Clinical Genetics Handbook; Arthur Robinson and Mary G. Linden