Impact of non-steroidal anti-inflammatory drugs on hypertensive disorders of pregnancy.

Objective: Non-steroidal anti-inflammatory drug (NSAID) use has the potential to adversely affect blood pressure in women with hypertensive disorders of pregnancy. We sought to evaluate this association.

Study Design: Women affected with severe hypertensive disorders of pregnancy were identified by retrospective chart review. The medication administration record was then used to identify controls (no NSAID exposure) until a sufficient number of patients were obtained, after which the cases (NSAID exposed) were identified in a chronological manner during the same study period until a 2:1 ratio was achieved. The primary outcome was the change in mean of all postpartum mean arterial pressures (MAP) throughout the hospital stay. Power analysis showed that 146 exposed and 73 unexposed subjects were necessary to obtain 90% power to detect a MAP difference of 10mmHg between the groups. Secondary outcomes included: initiation of anti-hypertensive medication, need for increased doses of anti-hypertension medication, and adverse events related to hypertension.

Results: 223 women had severe hypertensive disorders of pregnancy, of whom 75 (34%) were not exposed to NSAIDs and 148 (66%) were exposed. NSAID exposure was not associated with a difference in the average MAP postpartum (p=0.70), nor any of the secondary outcomes evaluated. Exposure to NSAIDs was less likely as serum creatinine increased (p=0.012).

Conclusion: In women with severe hypertensive disorders of pregnancy, NSAIDs did not appear to increase the average postpartum MAP, increase the requirement for anti-hypertensive medications, or increase the rate of adverse postpartum events.