What to expect from dating scan
Also the fetus cannot bend and twist too much yet, so the length of the body is fairly constant.
However, the accuracy of the ultrasound examination is always dependent on the skill of the sonographer and the quality of the equipment.
) the fetus is clearly seen on trans-vaginal ultrasound and the heart beat can be seen at this early stage (90 to 110 beats per minute under 6 to 7 weeks, then 110 to 200 beats per minute as the baby matures).
the baby and its heart beat can be detected relatively easily with trans-abdominal and trans-vaginal examination.
If the pregnancy is very early the gestation sac and fetus will not be big enough to see, so the transvaginal approach will give better pictures.
For transvaginal ultrasound you can have an empty bladder Dating scans are usually recommended if there is doubt about the validity of the last menstrual period.
Usually the expected date of delivery (EDD or EDC) is calculated from your last menstrual period - if the early dating scan calculates the EDD to be within 5 days of the EDD from your last menstrual period.
The EDD from the early dating scan is used - if the last menstrual period is not known or is unreliable, or the dating scan differs from the last menstrual period dating by more than 5 days.
While the scan is being carried out, the operator will usually explain what she/he is looking at, and you may be given a black-and-white printout of the picture to take home with you, as well as information and charts of various measurements.
In certain circumstances, for example, if there are any particular risks or problems, you may be able to have earlier or later scans if necessary.
An ultrasound scan transmits silent sound waves through your body tissues to create an image of your baby in your womb, which you and your partner will be able to see on a TV/computer screen.
The earlier the ultrasound is done, the more accurate it is at estimating the baby's due date.
Ultrasounds performed during the first 12 weeks of pregnancy are generally within 3 - 5 days of accuracy.In fact, seeing your baby moving around during the scan can be highly enjoyable and reassuring.