TNF-α Inhibitor Use During Pregnancy and the Risk of Preeclampsia: Population-based Cohort Study

Background: Although the clinical importance of preeclampsia is widely recognized, few treatment options are available for prevention. TNF-α inhibitors have been hypothesized to potentially prevent the disease. We aimed to examine whether exposure to TNF-α inhibitors during pregnancy reduces the risk of preeclampsia.

Methods: We conducted a population-based pregnancy cohort study using nationwide samples of publicly (Medicaid data, 2000-2018) and commercially (MarketScan Research Database, 2003-2020) insured pregnant women linked to their liveborn infants. Exposure was ascertained based on a filled prescription or administration code for TNF-α inhibitors during the first and second trimester of pregnancy. The outcomes included early-onset preeclampsia, late-onset preeclampsia, and small-for-gestational age. For baseline confounding adjustment, we leveraged propensity score overlap weights to estimate risk ratios (RR).

Results: Among 4 315 658 pregnancies in the Medicaid and the MarketScan cohort, 2736 (0.063%) were exposed to TNF-α inhibitors during the first trimester and 1712 (0.040%) during the second trimester. After adjustment, the risk of early-onset preeclampsia was not decreased among mothers exposed during the first trimester compared with unexposed women with treatment indications [RR pooled : 1.25, 95% confidence interval (CI) 0.93-1.67]. Similarly, the risk of late-onset preeclampsia was not decreased among mothers exposed during the second trimester compared with unexposed women (RR pooled : 0.99, 95% CI 0.81-1.22).

Conclusion: Contrary to the hypothesis, exposure to TNF-α inhibitors during pregnancy did not appear to be associated with a reduced risk of early-onset or late-onset preeclampsia. These findings do not support consideration of the use of TNF-α inhibitors for the prevention of preeclampsia.