Ultrasound accuracy for dating
» Incidence of chemotherapy-induced neutropenia in HIV-infected and uninfected patients with breast cancer receiving neoadjuvant chemotherapy » Characteristics and correlates of alcohol consumption among adult chronic care patients in North West Province, South Africa » Corneal donations in South Africa: A 15-year review » Wilderness medicine in southern Africa » Acute high-altitude illness We performed a prospective comparison of 2 ultrasound policies involving consecutive low-risk women in a midwife clinic in the Metro East region, Cape Town, Western Cape.
Information on the last menstrual period (LMP), the 1st symphysis-to-fundal height measurement (FH) and average gestation by ultrasonographic (US) fetal biometry was recorded.
Our aim was to determine the accuracy of the different dating methods, and of their combinations, since they are currently widely used in SA. Salomon LJ, Pizzi C, Gasparrini A, Bernard JP, Ville Y. Salomon LJ, Pizzi C, Gasparrini A, Bernard JP, Ville Y. Okland I, Gjessing HK, Grøttum P, Eggebø TM, Eik-Nes SH. two traditional sample-based models: validation on 9046 ultrasound examinations.
We performed a prospective study that compared the current US policy with a policy that included a routine booking scan. Symphysis-fundus measurements in screening for small-for-dates infants: A community based study in Gloucestershire. Prediction of the date of delivery based on first trimester ultrasound measurements: An independent method from estimated date of conception. Prediction of the date of delivery based on first trimester ultrasound measurements: An independent method from estimated date of conception.
Ultrasonography (US) in the 1st, or early 2nd trimester, is highly reproducible8 and widely used for dating, since early biological variability of fetal biometry is minimal.9 In the past, certain LMP was used for dating as long as the GA was within 7, 10 or 14 days of the estimate of GA by US,10 but now 1st, or 2nd trimester, US is increasingly recommended as the single dating method because of its smaller error rate.1 14 The current policy in the Western Cape Province of South Africa (SA) provides for a routine US examination between 18 - 23 weeks of the clinically estimated GA for low-risk pregnancies since this reduces the number of presumptive post- and pre-term deliveries as well as the number of referrals to a higher level of care for suspected deviations in fetal growth.15 The approximately 34% of women who typically present at 23 weeks16 do not routinely receive US.
Pregnancy dating is based on a pragmatic guideline incorporating information from the LMP, FH and early US (if available).17 The accuracy of this guideline and the clinical value of late US-based GA dating have not been assessed. Okland I, Gjessing HK, Grøttum P, Eggebø TM, Eik-Nes SH. two traditional sample-based models: validation on 9046 ultrasound examinations.
On some occasions it is still difficult to see and so we may ask if a more detailed internal ultrasound scan can be done trans-vaginally.
This is a simple procedure and does not cause any pain or harm to the pregnancy.
Benefits, harms, and costs: Accurate assignment of gestational age may reduce post-dates labour induction and may improve obstetric care through allowing the optimal timing of necessary interventions and the avoidance of unnecessary ones.Screening for Down's syndrome will happen at the dating scan if: The screening test for Down's syndrome used at this stage of pregnancy is called the combined test.The combined test involves a blood test and measuring the fluid at the back of the baby's neck (nuchal translucency) with an ultrasound scan.To determine whether ultrasound gestational age assessment is cost effective.
Evidence: Published literature was retrieved through searches of Pub Med or MEDLINE and The Cochrane Library in 2013 using appropriate controlled vocabulary and key words (gestational age, ultrasound biometry, ultrasound dating).Optimal management of pregnancy relies on accurate assessment of the gestational age (GA) of the fetus; which can be determined by the history of the last menstrual period (LMP), clinical estimation of the 1st symphysis-to-fundal height measurement (FH) or ultrasonographic fetal biometry.