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Ultrasound dating at 12-14 or 15-20 weeks of gestation? A prospective cross-validation of established dating formulae in a population of in-vitro fertilized pregnancies randomized to early or late dating scan

Saltvedt, S; Almstrom, H; Kublickas, M; Reilly, M; Valentin, Lil LU and Grunewald, C (2004) In Ultrasound in Obstetrics & Gynecology 24(1). p.42-50
Abstract
Objectives To determine the accuracy of established ultrasound dating formulae when used at 12-14 and 15-20 gestational weeks. Methods A total of 363 singleton pregnancies conceived after in-vitro fertilization (IVF) and randomized to a dating scan at 12-14 or 15-20 gestational weeks were studied. 'True' gestational age was calculated on the basis of the day of oocyte retrieval and was compared to gestational age calculated on the basis of seven dating formulae including the fetal biparietal diameter (BPD) and three dating formulae including BPD and fetal femur length (FL). The mean of the differences between estimated and true gestational age (systematic measurement error) and their SD (random measurement error) were calculated for each... (More)
Objectives To determine the accuracy of established ultrasound dating formulae when used at 12-14 and 15-20 gestational weeks. Methods A total of 363 singleton pregnancies conceived after in-vitro fertilization (IVF) and randomized to a dating scan at 12-14 or 15-20 gestational weeks were studied. 'True' gestational age was calculated on the basis of the day of oocyte retrieval and was compared to gestational age calculated on the basis of seven dating formulae including the fetal biparietal diameter (BPD) and three dating formulae including BPD and fetal femur length (FL). The mean of the differences between estimated and true gestational age (systematic measurement error) and their SD (random measurement error) were calculated for each formula. Results Three formulae showed systematic errors of less than -0.7 days at both early and late scanning. Two formulae overestimated gestational age at both early and late scanning by 5.7 and 3.1 vs. 2.3 and 2.8 days, respectively, while five formulae manifested very different systematic errors at early and late scanning. The formulae used for clinical management underestimated gestational age by a mean of 3 days when dating was performed at 12-14 weeks, and by a mean of 0.8 days when dating was done at 15-20 weeks. The random error was on average 1 day less when the scan was carried out early (2 vs. 3 days; P < 0.0005). Mean true gestational age at delivery in IVF pregnancies with spontaneous start of labor was 279 days (SD 12.9); excluding preterm deliveries it was 2 81 days (SD 8.1). Conclusions Ultrasound dating formulae originally intended for use in the middle of the second trimester do not necessarily perform well when used for dating earlier in gestation. The systematic and random error of any dating formula must be assessed for the gestational age interval in which the formula is intended to be used. Copyright (C) 2004 ISUOG. Published by John Wiley & Sons, Ltd. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ultrasound, in-vitro fertilization, gestational age, fetometry, ultrasonography, fetal, femur length, biparietal diameter, dating formulae
in
Ultrasound in Obstetrics & Gynecology
volume
24
issue
1
pages
42 - 50
publisher
John Wiley & Sons
external identifiers
  • pmid:15229915
  • wos:000222853100007
  • scopus:3142731955
ISSN
1469-0705
DOI
10.1002/uog.1047
language
English
LU publication?
yes
id
ec616a91-1c7f-4572-af31-206c5e598fae (old id 898646)
date added to LUP
2008-01-18 12:16:22
date last changed
2017-10-08 04:13:25
@article{ec616a91-1c7f-4572-af31-206c5e598fae,
  abstract     = {Objectives To determine the accuracy of established ultrasound dating formulae when used at 12-14 and 15-20 gestational weeks. Methods A total of 363 singleton pregnancies conceived after in-vitro fertilization (IVF) and randomized to a dating scan at 12-14 or 15-20 gestational weeks were studied. 'True' gestational age was calculated on the basis of the day of oocyte retrieval and was compared to gestational age calculated on the basis of seven dating formulae including the fetal biparietal diameter (BPD) and three dating formulae including BPD and fetal femur length (FL). The mean of the differences between estimated and true gestational age (systematic measurement error) and their SD (random measurement error) were calculated for each formula. Results Three formulae showed systematic errors of less than -0.7 days at both early and late scanning. Two formulae overestimated gestational age at both early and late scanning by 5.7 and 3.1 vs. 2.3 and 2.8 days, respectively, while five formulae manifested very different systematic errors at early and late scanning. The formulae used for clinical management underestimated gestational age by a mean of 3 days when dating was performed at 12-14 weeks, and by a mean of 0.8 days when dating was done at 15-20 weeks. The random error was on average 1 day less when the scan was carried out early (2 vs. 3 days; P &lt; 0.0005). Mean true gestational age at delivery in IVF pregnancies with spontaneous start of labor was 279 days (SD 12.9); excluding preterm deliveries it was 2 81 days (SD 8.1). Conclusions Ultrasound dating formulae originally intended for use in the middle of the second trimester do not necessarily perform well when used for dating earlier in gestation. The systematic and random error of any dating formula must be assessed for the gestational age interval in which the formula is intended to be used. Copyright (C) 2004 ISUOG. Published by John Wiley &amp; Sons, Ltd.},
  author       = {Saltvedt, S and Almstrom, H and Kublickas, M and Reilly, M and Valentin, Lil and Grunewald, C},
  issn         = {1469-0705},
  keyword      = {ultrasound,in-vitro fertilization,gestational age,fetometry,ultrasonography,fetal,femur length,biparietal diameter,dating formulae},
  language     = {eng},
  number       = {1},
  pages        = {42--50},
  publisher    = {John Wiley & Sons},
  series       = {Ultrasound in Obstetrics & Gynecology},
  title        = {Ultrasound dating at 12-14 or 15-20 weeks of gestation? A prospective cross-validation of established dating formulae in a population of in-vitro fertilized pregnancies randomized to early or late dating scan},
  url          = {http://dx.doi.org/10.1002/uog.1047},
  volume       = {24},
  year         = {2004},
}