Dating ultrasound measurements erin andy dating
We conclude that commonly used ultrasound reference charts have inaccuracies.
We have generated a CRL reference chart based on true gestational age in an IVF cohort that can accurately determine gestational age at 6–9 weeks of gestation.
Most of these charts are based on menstrual age to estimate gestational age at the day of the ultrasound examination, based on modest sample sizes, generated many years ago using ultrasound machines of poorer resolution, or used transabdominal measurements (which gives poorer pictures relative to a transvaginal approach) [6–8].
As such, there is considerable variability between current reference charts, and estimated gestational age can vary significantly depending on which chart is used.
All examinations were performed at three ultrasound centres that exclusively perform women’s health ultrasounds.
All ultrasounds were transvaginal, done on Advanced Technology Laboratories HDI 5000 ultrasound machines by experienced sonographers.
The Monash Chart, but none of the existing charts, accurately determined gestational age among an independent IVF twin cohort (185 twin pairs).
When applied to 3052 naturally-conceived singletons scans, The Monash Chart generated estimated due dates that were different to all existing charts ( all comparisons).
We then applied all six existing reference charts and our chart to estimate gestational age of CRL measurements obtained from 3052 consecutive first-trimester singleton ultrasound scans pregnancies at 6–9 weeks of gestation.Accurate dating of gestational age is central to good obstetric care.It allows the clinicians to better time gestation-specific antenatal screening tests, reduces erroneous labelling of pregnancies as very preterm, preterm, and small-for-gestational-age, and decreases the risk of inappropriate induction of labour [1–5].Ethics approval was obtained before we commenced the study (Project 05063, Monash Surgical Private Human Research Ethics Committee, Clayton, VIC, Australia).
For this retrospective database study where we used de-identified data in aggregate, the ethics committee specifically approved our request not to obtain individual patient consent.OBJECTIVES There are no international standards for relating fetal crown-rump length (CRL) to gestational age (GA), and most existing charts have considerable methodological limitations.