Triple test Triple test The triple test, also called triple screen, the Kettering test or the Bart's test, is an investigation performed during pregnancy in the second trimester to classify a patient as either high-risk or low-risk for chromosomal abnormalities (and neural tube defects). The term "multiple-marker screening test" is sometimes used instead. This term can encompass the "double test" and "quadruple test" (described below). The Triple screen measures serum levels of AFP, estriol, and beta-hCG, with a 70% sensitivity and 5% false-positive rate. It is complemented in some regions of the United States, as the "Quad screen" (adding inhibin A to
Quadruple-precision floating-point format switch) or simply as being synonymous with double precision (e.g. Microsoft Visual C++), rather than as quadruple precision. On a few other architectures, some C/C++ compilers implement codice_8 as quadruple precision, e.g. gcc on PowerPC (as double-double) and SPARC, or the Sun Studio compilers on SPARC. Even if codice_8 is not quadruple precision, however, some C/C++ compilers provide a nonstandard quadruple-precision type as an extension. For example, gcc provides a quadruple-precision type called codice_14 for x86, x86-64 and Itanium CPUs, and on PowerPC as IEEE 128-bit floating-point using the -mfloat128-hardware or -mfloat128 options; and some versions of Intel's C/C++ compiler