Catalyzes the stereospecific NADPH-dependent reduction of the C4-C5 double bond of bile acid intermediates and steroid hormones carrying a delta(4)-3-one structure to yield an A/B cis-ring junction. This cis-configuration is crucial for bile acid biosynthesis and plays important roles in steroid metabolism. Capable of reducing a broad range of delta-(4)-3-ketosteroids from C18 (such as, 17beta-hydroxyestr-4-en-3-one) to C27 (such as, 7alpha-hydroxycholest-4-en-3-one). 5beta-cholestan-3-one + NADP(+) = cholest-4-en-3-one + H(+) + NADPH 4,5beta-dihydrocortisone + NADP(+) = cortisone + H(+) + NADPH cortisol + H(+) + NADPH = 5beta-dihydrocortisol + NADP(+) corticosterone + H(+) + NADPH = 5beta-dihydrocorticosterone + NADP(+) 7alpha,12alpha-dihydroxycholest-4-en-3-one + H(+) + NADPH = 7alpha,12alpha-dihydroxy-5beta-cholestan-3-one + NADP(+) 7alpha-hydroxycholest-4-en-3-one + H(+) + NADPH = 7alpha-hydroxy-5beta-cholestan-3-one + NADP(+) epitestosterone + H(+) + NADPH = 5beta-dihydroepitestosterone + NADP(+) androst-4-ene-3,17-dione + H(+) + NADPH = 5beta-androstane-3,17-dione + NADP(+) H(+) + NADPH + progesterone = 5beta-pregnan-3,20-dione + NADP(+) 21-hydroxyprogesterone + H(+) + NADPH = 5beta-dihydrodeoxycorticosterone + NADP(+) aldosterone + H(+) + NADPH = 5beta-dihydroaldosterone + NADP(+) 17beta-hydroxyandrosta-1,4-dien-3-one + H(+) + NADPH = 17beta-hydroxy-5beta-androst-1-en-3-one + NADP(+) 17beta-hydroxyestr-4-en-3-one + H(+) + NADPH = 17beta-hydroxy-5beta-estran-3-one + NADP(+) 5beta-dihydrotestosterone + NADP(+) = H(+) + NADPH + testosterone androst-4-ene-3,11,17-trione + H(+) + NADPH = 17beta-hydroxyandrost-4-ene-3,11-dione + NADP(+) Subject to inhibition by high substrate concentrations. Inhibited by testosterone concentrations above 10 uM. Inhibited by the primary and secondary bile acids chenodeoxycholic acid and ursodeoxycholic acid. The N-terminus is blocked. Belongs to the aldo/keto reductase family.