NPPB and hydrops fetalis: In the larger RELAX-AHF-2 trial, the same 48-hour treatment with intravenous relaxin did not reduce the incidence of cardiovascular death at 180 days or worsening HF at 5 days compared to placebo13, but, in a large meta-analysis of all six phase 3 trials (n = 11,359), 48-hour infusion with relaxin was shown to reduce the risk of worsening HF to day 5 while also reducing serum creatinine, NT-proBNP and troponin levels14.