Accuracy of Ultrasound Estimated Fetal Weight in Small for Gestational Age and Appropriate for Gestational Age Grown Periviable Neonates
11. März 2017
29. November 2017
29. Dezember 2017 (online)
Objective Clinicians use estimated fetal weight (EFW) as a proxy for birth weight (BW) in the antenatal period. Our objective was to compare the accuracy of EFW obtained by ultrasound to BW among infants born during the periviable period and determine if accuracy of EFW varied among small for gestational age (SGA) versus appropriate for gestational age (AGA) grown neonates.
Study Design We included women who delivered between 230/7 and 256/7 weeks' gestation and had an EFW within 7 days of delivery. Mean percentage difference and median absolute percentage difference between EFW and BW were calculated.
Results Our cohort included 226 neonates with a mean gestational age of 241/7 ± 0.8 weeks and median BW of 653 g (interquartile range [IQR]: 580–750 g). The median absolute percentage difference between EFW and BW of fetal weight estimates was 9.2% (IQR: 3.6–17.2). EFW overestimated BW for 75% (n = 171) of the cohort. Among SGA infants, the mean percentage difference in EFW and BW was 16.2 ± 19.4% versus 6.9% ± 13.1% in AGA infants (p = 0.019).
Conclusion EFW overestimated BW in this cohort. In addition, ultrasound was less accurate among infants born SGA. These data are important to consider when counseling families facing periviable delivery.
- 1 Ecker JL, Kaimal A, Mercer BM. , et al; American College of Obstetricians and Gynecologists and the Society for Maternal–Fetal Medicine. #3: Periviable birth. Am J Obstet Gynecol 2015; 213 (05) 604-614
- 2 Cummings J. ; Committee on Fetus and Newborn. Antenatal counseling regarding resuscitation and intensive care before 25 weeks of gestation. Pediatrics 2015; 136 (03) 588-595
- 3 Stoll BJ, Hansen NI, Bell EF. , et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network. Pediatrics 2010; 126 (03) 443-456
- 4 Hadlock FP, Harrist RB, Sharman RS, Deter RL, Park SK. Estimation of fetal weight with the use of head, body, and femur measurements--a prospective study. Am J Obstet Gynecol 1985; 151 (03) 333-337
- 5 Committee on Practice Bulletins—Obstetrics and the American Institute of Ultrasound in Medicine. 175: Ultrasound in pregnancy. Obstet Gynecol 2016; 128 (06) e241-e256
- 6 Dudley NJ. A systematic review of the ultrasound estimation of fetal weight. Ultrasound Obstet Gynecol 2005; 25 (01) 80-89
- 7 Cohen JM, Hutcheon JA, Kramer MS, Joseph KS, Abenhaim H, Platt RW. Influence of ultrasound-to-delivery interval and maternal-fetal characteristics on validity of estimated fetal weight. Ultrasound Obstet Gynecol 2010; 35 (04) 434-441
- 8 Ethridge Jr JK, Louis JM, Mercer BM. Accuracy of fetal weight estimation by ultrasound in periviable deliveries. J Matern Fetal Neonatal Med 2014; 27 (06) 557-560
- 9 Stefanelli S, Groom KM. The accuracy of ultrasound-estimated fetal weight in extremely preterm infants: a comparison of small for gestational age and appropriate for gestational age. Aust N Z J Obstet Gynaecol 2014; 54 (02) 126-131
- 10 Alexander GR, Himes JH, Kaufman RB, Mor J, Kogan M. A United States national reference for fetal growth. Obstet Gynecol 1996; 87 (02) 163-168
- 11 Jouannic JM, Grangé G, Goffinet F, Benachi A, Carbrol D. Validity of sonographic formulas for estimating fetal weight below 1,250 g: a series of 119 cases. Fetal Diagn Ther 2001; 16 (04) 254-258
- 12 Grantz KL, Grewal J, Albert PS. , et al. Dichorionic twin trajectories: the NICHD Fetal Growth Studies. Am J Obstet Gynecol 2016; 215 (02) 221.e1-221.e16
- 13 Hoopmann M, Bernau B, Hart N, Schild RL, Siemer J. Do specific weight formulas for fetuses < or = 1500 g really improve weight estimation?. Ultraschall Med 2010; 31 (01) 48-52