Miscalculation of pregnancy dating
Miscalculation of pregnancy dating - fake dating
A due date calculator calculates your estimated due date (EDD) which is an ESTIMATE of the day you are likely to go into labor spontaneously (without medical intervention).Only about 4% of babies are born on their estimated due dates but the majority (70%) are born within 10 days either side of their due dates.
The estimated due date is also known as the estimated date of confinement (EDC).
On This Page ► Due dates can be calculated either by formula or from ultrasound measurements of the growing baby.
Formulas are quick and easy and can be used by anyone.
However, ultrasound in the first trimester is the most accurate method for establishing or confirming a due date.
In the US, the American College of Gynecologists and Obstetricians has issued recommendations which define when it is appropriate to use an LMP formula to calculate an EDD and when an ultrasound based EDD should take precedence.
Since the actual date of conception is not normally known, the LMP formula begins counting pregnancy from the first day of a women's last menstrual period (LMP).
This can be a little confusing since counting starts about two weeks before true pregnancy begins.
But it does provide a useful starting point for calculation of due dates and pregnancy progress.
When to use the LMP formula: Despite its inherent weaknesses, the LMP formula is great for pregnancy dating when ultrasound has not yet been performed or is not available.
It is also the appropriate method for calculating due dates when pregnancies result from artificial reproductive techniques (ART).
Read more The terminology of pregnancy dating is based on the LMP formula.
Counting pregnancy from LMP is the basis of gestational ageing which is the way pregnancy progress is measured and recorded.