ST. PETE BEACH, FLA. — The use of oral steroids for asthma during pregnancy has long been discussed as a possible cause of orofacial clefts in newborns, but findings from a large cohort study suggest this is not the case.
In nearly 82,000 mother/infant pairs, not a single infant with an orofacial cleft was born to any of the more than 400 women who received at least one oral steroid prescription in the 90 days before pregnancy or during early pregnancy, Janet R. Hardy, Ph.D., reported at the annual meeting of the Teratology Society.
The findings could put an end to long-held beliefs—based on findings in laboratory animals decades ago—that a link exists between the medication and an increased risk for such defects.
About 6% of mothers in the retrospective population-based cohort study were asthmatic, and nearly 2% had other respiratory conditions. A total of 130 babies included in the study were born with orofacial cleft; only 6 of these were born to asthmatic mothers, and 3 others were born to women with other respiratory conditions. None of the nine mothers had received a prescription for an oral steroid during pregnancy, said Dr. Hardy, of the University of Massachusetts, Worcester.
The relative risk of cleft overall in this study was 1.30; the relative risk in babies born to women who received a prescription for any type of steroid medication was 1.26.
Dr. Hardy noted that the study, based on data in automated medical records from 1991 to 1999, is limited by its basis on prescribed medications. Medications prescribed do not necessarily equate to medications taken, she said, noting that she also was unable to study asthma severity, maternal smoking, family history, and racial and ethnic background.
Adjustment for other possible confounders, including other medications used, did not affect the results, however, she said.
Asthma complicates 3.7%–8.4% of pregnancies, and these findings suggest that any steroid use is associated with only a slightly increased risk of orofacial clefts.
Given the small overall risk with any steroid use and the apparent absence of risk with oral steroids, it is of concern that the data show a decline in the prescribing of oral steroids for the treatment of asthma in the first trimester, Dr. Hardy said.
In the prepregnancy period, 318 mothers (including 203 who were asthmatic) received at least one oral steroid prescription. In early pregnancy, however, only 149 (including 89 who were asthmatic) received at least one oral steroid prescription.
The risks associated with uncontrolled asthma are likely to be worse for the fetus than the risks of asthma medications, she concluded.