Related Experiment Video
Updated: Sep 28, 2025

Comprehensive Evaluation of the Effectiveness and Safety of Placenta-Targeted Drug Delivery Using Three Complementary Methods
Published on: September 10, 2018
Omeprazole Administration in Preterm Preeclampsia: a Randomized Controlled Trial to Study Its Effect on sFlt-1
Rugina I Neuman1,2, Milan D Baars2, Langeza Saleh1,2
1Department of Internal Medicine, Division of Pharmacology and Vascular Medicine (R.I.N., L.S., M.B., A.H.v.d.M., W.V., A.H.J.D.), Erasmus MC University Medical Center, Rotterdam, The Netherlands.
Background:
Low sFlt-1 (soluble Fms-like tyrosine kinase-1) and ET-1 (endothelin-1) levels have been reported in preeclamptic women using proton pump inhibitors.
Methods:
Here, we examined whether the proton pump inhibitor omeprazole could acutely reduce sFlt-1 and ET-1 (measured as CT-proET-1 [C-terminal pro-endothelin-1]), or increase free PlGF (placental growth factor) in 20 women with confirmed preeclampsia. Primary outcome was specified as the difference in sFlt-1, PlGF, or CT-proET-1 after 4 days of omeprazole versus 20 preeclamptic women not receiving omeprazole.
Results:
Mean maternal age was 30 years, and median gestational age was 30+3 weeks. Baseline sFlt-1 levels were identical in both groups, and the same was true for PlGF or CT-proET-1. After 4 days, sFlt-1 levels remained similar in women not receiving omeprazole compared with women receiving omeprazole, while the levels of PlGF and CT-proET-1 also did not differ between groups. Women receiving omeprazole had a similar prolongation of pregnancy after inclusion compared with those in the nonomeprazole group (median 15 versus 14 days). Except for a higher neonatal intubation rate in the nonomeprazole group (31% versus 4%, P=0.02), there were no differences in maternal/perinatal complications. Finally, making use of the placenta perfusion model, we established that both omeprazole and its S-isomer, esomeprazole, when maternally applied, reached the fetal compartment (fetal-to-maternal ratio's 0.43-0.59), while only esomeprazole inhibited placental sFlt-1 release.
Conclusions:
Administration of omeprazole to women with confirmed preeclampsia does not alter their circulating levels of sFlt-1, PlGF, or ET-1, arguing against a role of this drug as a treatment for this syndrome.

