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.
Most patients undergo an ultrasound at around 18-20 weeks (about four and a half to five months). Normally, at this stage of pregnancy we can determine the baby's sex, but not always. The position of the baby during the ultrasound is the most important aspect in our ability to tell the baby's sex, andthere's no way to influence that. For obvious reasons, it's usually easier to see if the baby is a boy. One reliable method is using amniocentesis to check the baby's chromosomes. This test is usually performed on a mother who is 35 years or older, for the purpose of identifying possible genetic problems.