Ultrasound Rev Obstet Gynecol. The size of the baby correlates less and less with its age as time goes on. Ultrasonography in pregnancy. For transvaginal ultrasound you can have an empty bladder When is it recommended? 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. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Ultrasound dating at 12—14 weeks of gestation.
There are many reasons why what appears to be one thing on ultrasound may actually be something else.
Can your pregnancy scan give the wrong due date?
Ultrasound examinations from 12 to 22 weeks are regarded as being within 10 days of accuracy or up to 10 days earlier or 10 days later than the woman's calculated due date. Methods This cross-sectional study included consecutive pregnant women receiving antenatal care at two tertiary health institutions in Enugu, Nigeria, from January 1, to March 31, The mean age of the respondents was Because of the risk of redating a small fetus that may be growth restricted, management decisions based on third-trimester ultrasonography alone are especially problematic; therefore, decisions need to be guided by careful consideration of the entire clinical picture and may require close surveillance, including repeat ultrasonography, to ensure appropriate interval growth. Lynch CD, Zhang J. First pregnancy ultrasound is the viability scan is the dating with the dating from your last menstrual dating is an ultrasound early pregnancy. Evidence suggests that, in the first 20 weeks of pregnancythe first ultrasound may be the most accurate tool for predicting when your baby will be born.