First-trimester or second-trimester screening, or both, for Down's syndrome

The First- and Second-Trimester Evaluation of Risk (FASTER) Trial is conducted with the aim of giving direct comparative data on lately available screening approaches to Down's syndrome from a large population followed prospectively. First-trimester combined screening at 11 weeks of gestation is found to be better than second-trimester quadruple screening however at 13 weeks has results similar to second-trimester quadruple screening.