Patient: When determining your due date is it more accurate to go by the sonogram are your last missed period to know how many weeks you really are because those dates were two weeks apart for me. which one is more accurate.
Doctor: I understand your hesitation about estimated pregnancy due date. Absolutely, the preferred method to get an estimate of the delivery due date is to use the first day of your last menstrual period to calculate it; this method is also the most accurate than the sonogram to calculate the fetal age therefore it will be also be more accurate in estimating the due date.This method is also known as Naegele’s Rule, this technique says that forty weeks from any date on the calendar is equal to counting forward nine calendar months plus one week. So if we add nine months plus one week to the date which marks the first day of woman’s last menstrual period, the result will be forty weeks, or the average due date. I hope I cleared your doubt, I wish you the best.