Opinion
Safety of corticosteroids in pregnancy: Is it the drug or the disease?
Concerns about the teratogenicity of corticosteroids were raised as early as the 1950s, but research findings have been inconsistent.
according to a study examining autoimmune disease in pregnancy. Corticosteroid use in any trimester increased that risk from 100%-400%, regardless of how active the arthritis was.
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The study found that women with RA had more than double the risk for preterm delivery, compared with a cohort without autoimmune disease (relative risk, 2.09; 95% confidence interval, 1.50-2.91). For women with juvenile idiopathic arthritis (JIA), the relative risk was 1.81 for preterm delivery (95% CI, 1.14-2.89).
The prospective cohort study, part of the Organization of Teratology Information Specialists Autoimmune Disease in Pregnancy Project, enrolled 657 women with RA and 170 women with JIA. The study also included a comparison group of 564 women without autoimmune disease. All of those included in the study were enrolled before 19 weeks’ gestation and delivered live-born infants during 2004-2017.
The study adds to a clinically important area of research that has yielded sometimes conflicting results; clarity has also been impeded by a variety of methodologies. Though several analyses have shown higher risk of preterm delivery in women with RA, not all studies have adjusted for medication use and disease activity, Chelsey F. Smith, MD, and her coauthors wrote in Arthritis Care & Research. Further, how women with JIA fare in pregnancy has not been well studied, they said.
Dr. Smith, a rheumatologist at the University of California, San Diego, and her colleagues included many baseline covariates in their analysis of pregnancy outcomes; these included maternal age and race, socioeconomic status, body mass index, previous adverse pregnancy outcomes, and comorbidities, including autoimmune disease. Adverse pregnancy outcomes during the studied pregnancy were also included as covariates, and deliveries were considered preterm if labor began before 37 weeks’ gestation.
For women with RA, a higher active disease score at any point during pregnancy was associated with a significantly higher risk of preterm delivery, even after adjustment for other potential risk factors, including first-trimester corticosteroid use (adjusted risk ratio, 1.52; 95% CI, 1.06-2.18). The persistence of this association, wrote Dr. Smith and her colleagues, implies “that active disease in RA may contribute to [preterm delivery] independent of medications,” perhaps through the action of proinflammatory cytokines that may stimulate prostaglandins and provoke uterine contractions.
The researchers found, though, that this association between disease activity and risk for preterm birth did not hold true for women with JIA, leaving part of the mystery unsolved.
However, women with both RA and JIA who used corticosteroids in any trimester were more likely to have a preterm delivery, as were women with JIA who used NSAIDs in the first trimester of pregnancy. The use of disease-modifying antirheumatic drugs (DMARDs) and biologics in any trimester did not confer increased risk for preterm delivery in women with either disease state.
There were other differences between the groups: Women with JIA were overall younger, but had more prepregnancy hypertension, which “may have contributed to the elevated incidence of preeclampsia seen in this group,” the investigators wrote. Fever was more common in women with JIA, and had an independent association with preterm delivery, as did first trimester NSAID use in this group alone.
Dr. Smith and her colleagues hypothesized that the relative heterogeneity of the JIA group may mean that disease activity still influenced outcomes.
Among other comorbidities, gestational diabetes (GDM) was more common in the RA group than in the JIA group or the comparison cohort, and was associated with a significantly higher risk for preterm delivery in women with RA, even after accounting for preeclampsia and hypertension in a multivariate analysis.
Dr. Smith and her colleagues pointed out that it was difficult to account for physician behavior in managing pregnancy in these high-risk women. “Additionally, given that women with both RA and GDM are at a particularly high risk for perinatal complications, we can speculate that the obstetricians in this group were perhaps more aggressive about inducing at an earlier gestational age than in other groups, but this information was not available in the dataset.”
Through phone interviews, investigators obtained information about prescription and nonprescription medication use during pregnancy; women were also asked about use of other substances and occupational exposures, infections, and prenatal testing and other medical procedures. Another telephone interview conducted soon after delivery asked about birth outcomes. Abstracted medical record data were used to verify and supplement the interview information.
When looking at treatments used, Dr. Smith and her colleagues grouped autoimmune disease medications into DMARDs, non-DMARD biologic medications, corticosteroids, and NSAIDs.
Disease activity assessment, conducted at intake and at 32 weeks’ gestation, used the Health Assessment Questionnaire, pain scores, and patient global disease activity to calculate a Patient Activity Scale score ranging from 0 to 10. Patients with a score over 3.7 were classified as having high disease activity.
Dr. Smith and her colleagues said that the study’s strengths included its prospective design and robust statistical schema. Also, using data about corticosteroid use and disease activity earlier in pregnancy avoided the inclusion of a reverse causation effect, where systemic inflammatory changes associated with preterm delivery might provoke more disease activity and a consequent boost in corticosteroid use.
However, the researchers said, the overall numbers of participants with preterm delivery was relatively small, and the JIA cohort was small as well.
“Further analyses are necessary to look at other categories of arthritis affecting women of childbearing age, racial disparities in these populations, as well as the influence of disease activity in the later stages of pregnancy on other perinatal factors” that can contribute to preterm delivery, said Dr. Smith and her colleagues.
The collaborative research group that collected data for the study receives research funding from several pharmaceutical companies. None of the authors reported any personal conflicts of interest.
SOURCE: Smith CF et al. Arthritis Care Res. 2018 Aug 21. doi: 10.1002/acr.23730.
