Pregnancy due date based on ultrasound dating dating russia and ukraine girls for
If the ultrasound date is within seven days of your LMP date, we would stick with your LMP date.
Ultrasounds done later in the pregnancy are less accurate for dating, so if your due date is set in the first trimester, it shouldn't be changed.
It is not used by medical professionals to describe pregnancy length and is solely a political term.
Sometimes we do use a trimester system if we are seeking to describe how far along a woman is in general terms.
Medical professionals consider delivery premature when it occurs before 36 weeks, and extremely premature when it occurs before 28 weeks’ LMP.
The expected duration of a pregnancy is 40 weeks from the first day of LMP (four weeks more than the traditional nine months by which many count).
Ultrasound dating is based on a series of measurements of the gestational sac in very early pregnancies and of the embryo or fetus itself as pregnancy progresses.
However, unless there is a great difference between what is seen on an ultrasound and what was reported as LMP, doctors still use LMP to establish a due date.
For example, if in the first trimester the ultrasound estimate falls within one week of the LMP estimate, we still use LMP to determine due date and length of pregnancy.
If the ultrasound estimate differs by more than one week from the LMP, we would use the ultrasound estimate for the due date.