Anti-angiogenic factors such as sFlt/sEng contribute to the pathology seen in preeclampsia. Activin A, which is released by the placenta following exposure to oxidative stress and elevated in preeclampsia, may interact with sFlt/sEng during the disease process. Using placental explant cultures, we determined that transcription of sFLT1, ENG and INHBA was upregulated following exposure to oxidative stress or IL-6. Explants treated with Activin A did not increase transcription of sFLT1, ENG. Conversely, treatment of placental explants with sFlt/sEng did not increase transcription of INHBA. These data may suggest that Activin A and sFlt/sEng contribute to preeclampsia via separate pathways. ? 2013 International Society for the Study of Hypertension in Pregnancy.