Nuchal scan vs dating scan
Research shows that routine obstetric ultrasound before 24 weeks gestational age can significantly reduce the risk of failing to recognize multiple gestations and can improve pregnancy dating to reduce the risk of labor induction for post-dates pregnancy.
There is no difference, however, in perinatal death or poor outcomes for babies.
Some abnormalities detected by ultrasound can be addressed by medical treatment in utero or by perinatal care, though indications of other abnormalities can lead to a decision regarding abortion.
Perhaps the most common such test uses a measurement of the nuchal translucency thickness ("NT-test", or "Nuchal Scan").
Gestational age is usually determined by the date of the woman's last menstrual period, and assuming ovulation occurred on day fourteen of the menstrual cycle.
The procedure is a standard part of prenatal care in many countries, as it can provide a variety of information about the health of the mother, the timing and progress of the pregnancy, and the health and development of the embryo or fetus.
In normal state, each body tissue type, such as liver, spleen or kidney, has a unique echogenicity.