Accuracy of ultrasound dating at 6 weeks
pregnancy - Actual date of conception - Parenting Stack Exchange
dating a new york standard pocket watch dogs The most common test is the ultrasound, which measures the size of the fetus from crown to rump is added to 6 weeks to determine gestational age. Gestational sac measurements are highly accurate from 4 weeks gestation. The doctor adds 280 days to the first day of your last menstrual cycle to determine a due date.