Pregnancy dating ultrasound calculator
Generally obstetricians or physicians initially calculate pregnancy from your last period without adjusting for an irregular cycle length.This initial estimation may then be superseded or confirmed by an ultrasound.Home pregnancy tests are available which can be used in the early stages of pregnancy to measure pregnancy progress.Other, less important methods (used by health professionals) for assessing age of pregnancy include measurement of fundal height (size of mother's belly), age of baby's first heart- beat, and time when mom first feels baby's movement.Our calculator strives for the highest accuracy, but your pregnancy progress may differ from the calculator's results for a number of reasons including possible miscalculation; errors in input data; individual variations in timing of ovulation and/or conception.
In addition, each pregnancy differs, so any dates, weights and lengths should be considered general information for interest only.LMP formulas are not suitable in a number of situations including the following: LMP is not known or is not certain, birth control pills were taken in the two months before LMP, the menstrual cycle is irregular, you are carrying multiples (twins or more).Although age of pregnancy based on ultrasound measurements is more accurate than age of pregnancy based on LMP, both are estimates and not definitive statements.Just 4% of babies are born on their due date while 70% are born within 10 days of the estimated due date.
The remaining 30% are born more than 10 days before the due date or more than 10 days after the due date.
If there is a significant difference between gestational age according to LMP and gestational age according to the ultrasound, you may be given a new gestational age and due date based on the ultrasound measurements.