Five dating methods: LMP, FH, US and their combinations, were assessed against the actual day of delivery (ADD).
The most common misconception we encounter almost daily, has to do with how accurate ultrasounds are in fixing the EDC at different stages of pregnancy.
Ultrasound has become so helpful that obstetricians now refer to the time before it was used routinely as “the olden days.” We use it to diagnose twins early on; we use it to document appropriate growth as the pregnancy progresses; we use it to determine fetal health; and we use it to guide conversion of breech to vertex (head-first) position and to guide amniocentesis.
Of all of these uses, dating the pregnancy is the most common reason to use ultrasound, particularly when the expectant mother cannot remember the date of her last period (as in breast-feeding or irregular cycles).
Outcomes: To determine whether ultrasound dating provides more accurate gestational age assessment than menstrual dating with or without the use of ultrasound.
To provide maternity health care providers and researchers with evidence-based guidelines for the assignment of gestational age.