During this time, he may or may not change the due date of your child, and thus he may reevaluate the conception date of the fetus.
A full-term gestational age is 40 weeks, but keep in mind that any time between 38 and 40 weeks is considered full term.
Accuracy of dating pregnancy with ultrasound
Babies don't all come in the same size, and thus a larger baby may influence a doctor to predict an earlier due date. In conclusion, the closer an ultrasound is performed to the actual date of conception, the more accurate it generally will be.
Keep in mind that conception actually occurs when the sperm meets the egg and this may not necessarily happen on the day the intercourse takes place.
You can calculate your due date by subtracting three months from the first day of your last menstrual period (LMP) and then add a week. A pregnancy is based on being 280 days long, which is 40 weeks (more like 10 months not 9! When we give you a due date we consider 37 to 42 weeks to be full-term, so even if your baby is born two weeks before your due date it is not considered premature.
Once you find out you are pregnant, you'll immediately want to know when the baby will be due.
Determining the due date generally involves estimating the conception date, but this can be tricky.
For women with regular periods, calculating the conception of your fetus is really based on a formula, which causes the due date to be close to the actual date of delivery.For women who have irregular periods, however, determining the date of conception can be difficult to do. The answer really depends upon the woman and the method of determining the due date.Some doctors rely on the use of an ultrasound to determine the actual due date of the baby.Most doctors, however, choose the initial due date simply based on the first day of your last period.Determining how accurate are conception dates really depends upon how the date is calculated.There are several methods that obstetricians use to predict this date, including the following: As your pregnancy progresses, your doctor will monitor the growth of your baby.