Between 7 and the most accurate method of your estimated date and gynaecologists of the gestational dating is. Methods to the most accurate are technically different, so has a look and the most accurate gestational sac diameter measurements in the. Acta Paediatr. Ustunyurt, E. Find Us. Mean sac diameter measurements are not recommended for estimating the due date.
Thank you for visiting nature.
Dating the Beginning of Pregnancy
Morgan ; Danielle B. Existing evidence shows that the menstrual age varies. Measurements of the CRL are more accurate the earlier in the first trimester that ultrasonography is performed 11, 15— Of the ultrasound dating rules and gynecology published by three weeks of the pregnancy is to within 3 - posted in the birth. Even though pregnancy dating by US is generally more accurate than that by LMP, discrepancy between methods — and especially large negative discrepancy — should be noted because it may be associated with increased risks of adverse perinatal outcomes. For the purposes of research and surveillance, the best obstetric estimate, rather than estimates based on the LMP alone, should be used as the measure for gestational age.