In an effort to allow for this discrepancy, many baroque ensembles adjust their tuning to the repertoire being performed: aâ= 415hz for late baroque music, aâ=392hz for French music, aâ=440hz for early Italian music and aâ=430hz for classical repertoire.
Ultrasound uses the size of the fetus to determine the gestational age (the time elapsed since the the first day of the last menstrual period). The accuracy of the ultrasound estimate of the gestational age varies according to the gestational age.Ultrasound measurement of the embryo or fetus in the first trimester (up to and including 13 6/7 weeks of gestation) is the most accurate method to establish or confirm gestational age [24].ltrasound uses the size of the fetus to determine the gestational age (the time elapsed since the the first day of the last menstrual period). The accuracy of the ultrasound estimate of the gestational age varies according to the gestational age.
For example: If you have an ultrasound before you're 14 weeks along and the fetal size suggests a due date that's more than seven days different from an estimated due date based only on your menstrual period, the ultrasound due date should be the one that is accepted as accurate.