BACKGROUND: @entity1433 are scavengers of reactive @entity26 species (ROS). We aim to investigate associations between @entity1433 in various fluids in (sub)fertile couples and fertility outcome parameters. METHODS: In 156 couples undergoing assisted reproduction techniques (ART), we measured the concentrations of @entity2041 ( @entity2197 ), @entity462 ( @entity2569 ), @entity1255 ( @entity5784 ) and @entity24970 (CGS) and fertility outcome parameters in the ejaculate, purified spermatozoa and follicular fluid. RESULTS: All @entity1433 were detectable in most ejaculates, spermatozoa and follicular fluids, of which @entity2569 concentrations were highest. @entity1432 concentrations in the ejaculate were similar in fertile and subfertile @entity1 . However, @entity5784 in follicular fluid was higher in @entity1 with @entity46 compared with @entity1 in the idiopathic subfertile group (P=0.04). The @entity2197 , @entity2569 , @entity5784 and CGS concentrations in spermatozoa of subfertile @entity1 were significantly higher compared with @entity1 in the idiopathic subfertile group and fertile @entity1 (P<0.001). Most notably, @entity5784 concentrations in both the ejaculate and follicular fluid were negatively associated with embryo quality on culture day 3 in the IVF/ICSI procedure. CONCLUSIONS: Spermatozoa of subfertile @entity1 contain significantly higher @entity1432 concentrations as compared with those of fertile @entity1 . The detrimental effect on embryo quality of a high @entity5784 concentration in the ejaculate and in follicular fluid is intriguing and may suggest that @entity5784 is inversely associated with fertility outcome.

XXXX , @entity2041 and related @entity1433 affect fertility parameters in the (sub)fertile couple.

@entity1 :: ('9606', 'Species') :: ['women', 'men'] @entity1433 :: ('MESH:D013438', 'Chemical') :: ['Thiols', 'thiols'] @entity462 :: ('MESH:D003545', 'Chemical') :: ['cysteine'] @entity1255 :: ('MESH:D006710', 'Chemical') :: ['homocysteine'] @entity2569 :: ('CHEBI:17561', 'Chemical') :: ['Cys'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity24970 :: ('MESH:C028505', 'Chemical') :: ['cysteinylglycine'] @entity2041 :: ('MESH:D005978', 'Chemical') :: ['glutathione'] @entity5784 :: ('CHEBI:17588', 'Chemical') :: ['Hcy'] @entity2197 :: ('CHEBI:16856', 'Chemical') :: ['GSH'] @entity1432 :: ('CHEBI:29256', 'Chemical') :: ['thiol', 'Thiol'] @entity46 :: ('MESH:D004715', 'Disease') :: ['endometriosis']
@entity1255 :: (MESH:D006710,Chemical) :: ['Homocysteine']
