Reliability of ultrasound dating stop windows xp updating
This is because the fetus is growing so quickly that there is a big difference in size from week to week.Also the fetus cannot bend and twist too much yet, so the length of the body is fairly constant.Sometimes a trans-vaginal examination shows that your pregnancy is less advanced than expected.The earlier the ultrasound is done, the more accurate it is at estimating the baby's due date.
This is an interesting sidebar that provides some latitude in an otherwise firm stance echoing the RADIUS trial findings.
However, the accuracy of the ultrasound examination is always dependent on the skill of the sonographer and the quality of the equipment.
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 baby and its heart beat can be detected relatively easily with trans-abdominal and trans-vaginal examination.
This is presuming that the pregnancy is actually at this stage of development.