An ultrasound exam is a procedure that uses highfrequency sound waves to scan a womans abdomen creating a picture sonogram of the baby and placenta.
What they look for in a 20 week ultrasound a 20week ultrasound or anatomy scan checks for a number of things the sonographer will look at and measure babys body parts to make sure they look normal and measure the right size.
ultrasound is defined by the american national standards institute as sound at frequencies greater than 20 khz in air at atmospheric pressure ultrasonic waves have wavelengths of 19 cm or less perception humans the upper frequency limit in humans approximately 20 khz is due to limitations of the middle ear auditory sensation can occur if highintensity ultrasound is fed directly.
A history of ultrasonography in obstetrics and gynecology part 2 realtime the real revolution the innovation which had soon completely changed the practice of ultrasound scanning was the advent of the realtime scannersthe first realtime scanner better known as fast bscanners at that time was developed by walter krause and richard soldner with j paetzold and and otto kresse and.
What is an ultrasound scan an ultrasound scan involves transmitting high frequency sound waves through the uterus these bounce off the baby and the returning echoes sound waves are translated by a computer into an image on a screen that reveals the babys position and movements.
Nuchal translucency is the name for the fluid behind the neck of your baby a collection of this fluid is taken during the 1 st trimester scan to determine chromosomal abnormality normal fetuses accumulate fluid under the skin behind the head and neck between 9 and 14 weeks of pregnancy.
While ultrasound scanning doesnt pose the same dangers to human and fetal health as ionizing radiation it is a mistake to think that ultrasound is entirely safe for a baby growing in your womb.
Bmj article about why cord early cord clamping must stop letter about neonatal resuscitation in archives of disease in childhood clamping the umbilical cord at birth is not necessary although it has been convenient so that the baby can be removed from its mother before delivery of the placenta usually 5 to 10 minutes after the birth of the baby.
Your due date is considered to be 40 weeks or 280 days after your last menstrual period or 38 weeks or 266 days after ovulation if an early ultrasound is used to determine or shift your due date its still based on this basic idea of a 280day gestational period.