No Link Between Asthma Rx and Birth Defects

Birth defects not associated with asthma medication

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Pregnant women with asthma can breathe a sigh of relief when it comes to using their inhaler. A new study has shown no significant link between asthma medication use and birth defects.

According to a new study, there was no link between asthma medication and most birth defects.

There was an positive association associated with some birth defects but more studies need to be conducted before a true link between asthma medication usage and these birth defects could be established.

"Ask your doctor about birth defect risk factors."

The recent study of data from the National Birth Defects Prevention Study involving 9,579 infants was led by Shao Lin, Ph.D., from the Department of Epidemiology and Biostatistics, University at Albany, School of Public Health, Rensselaer, New York. The data was collected from October 1997 until December 2005. Out of the 9,579 infants, 2,853 had one or more birth defects and 6,726 infants had no birth defects and were part of the control aspect of the study.

Of the birth defects included were limb deficiencies as well as diaphragmatic hernia (a hole in the diaphragm), esophageal atresia (where the esophagus does not connect to the stomach), small intestinal atresia (narrowing of the small intense), anorectal atresia (rectum does not develop properly), neural tube defects (openings in the brain or spinal cord) and omphalocele (abdominal wall defect).

Limb deficiencies occurs in approximately one out of 2,500 births. Diaphragmatic hernia occurs in approximately one out of 2,400 births. Esophageal atresia occurs in approximately one in 4,000 births. Small intestinal atresia occurs in approximately one out of 2,500 births.

Anorectal atresia occurs in approximately one out of 5,000 births. Neural tube defects occur in approximately one out of 1,000 births. Omphalocele occurs in approximately one out of 5,000 births.

According to the study, about four to 12 percent of pregnant women have asthma. The study focused on asthma medication usage, such as a bronchodilator or anti-inflammatory medication between one month prior to pregnancy up to the third month of pregnancy, and their effect on increased birth defect risk.

Telephone surveys, including medication usage as well as other risk factors, were used to evaluate any potential link between asthma medication and increased birth defect risk.

There were no association between asthma medication and increased risk of limb deficiencies, diaphragmatic hernia, small intestinal atresia and neural tube defects.

There was a positive association between esophageal atresia and bronchodilator usage, anorectal atresia and anti-inflammatory usage as well as omphalocele and usage of both types of asthma medication. This association may not entirely be due to asthma medication, notes the study.

The mother's asthma severity may be a factor as well as hypoxia, which is a deprivation of enough oxygen according to the researchers. Future studies need to evaluate whether or not the asthma medication was the reason for this increased risk of developing esophageal atresia, anorectal atresia and omphalocele.

While the birth defects were not the most common, they are completely uncommon. According to the Central Intelligence Agency (CIA), there are approximately four million births a year and out of those 160,000 to 480,00 are to women with asthma.

Not having to worry about asthma medication usage during pregnancy for these birth defects will definitely be good news to women with asthma.

No funding information was published. No conflicts were listed.

This study was published in the January edition of Pediatrics.

Reviewed by: 
Review Date: 
January 23, 2012
Last Updated:
January 23, 2012