Prenatal Midtrimester Fetal Long Bone Measurements and the Prediction of Small-for-Gestational-Age Fetuses at Term

Abstract

Objective To determine if the length of fetal long bones (LB) at mid-trimester ultrasound is predictive of small-for-gestational-age (SGA) newborns at term delivery.

Methods Retrospective evaluation of 6,781 women between 18 and 24 weeks' gestation at Magee-Womens Hospital (MWH). Gestational age (GA) was confirmed by first- or second-trimester ultrasound and patient's last menstrual period. Data were accrued from the institutional database at MWH. LB measurements were normalized to GA at the time of the ultrasound. The ratio was correlated with the probability of delivering an SGA newborn at term.

Results In all, 583 women were identified with an SGA newborn (8.6%). LB-to-GA ratios were associated with the probability of delivering an SGA newborn at term (p < 0.001). There was no single LB that proved to be superior in predicting an SGA newborn.

Conclusion There is a significant association between LB-to-GA ratio at midtrimester and the probability of SGA at term.

Keywords

femur length - ultrasound - small for gestational age

Notes

Presented at 2010 American Institute of Ultrasound in Medicine Annual Convention, San Diego, California, United States, March 24–27, 2010.

• References

• 1 ACOG. American College of Obstetrics and Gynecology Technical Bulletin #. 134, 2013, American College of Obstetrics and Gynecology, Washington DC.
• 2 Barker DJ, Osmond C, Golding J, Kuh D, Wadsworth ME. Growth in utero, blood pressure in childhood and adult life, and mortality from cardiovascular disease. BMJ 1989; 298: 564-567
• 3 Figueras F, Eixarch E, Meler E , et al. Small-for-gestational-age fetuses with normal umbilical artery Doppler have suboptimal perinatal and neurodevelopmental outcome. Eur J Obstet Gynecol Reprod Biol 2008; 136: 34-38
• 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: 333-337
• 5 Alexander GR, Himes JH, Kaufman RB, Mor J, Kogan M. A United States national reference for fetal growth. Obstet Gynecol 1996; 87: 163-168
• 6 Kurtz AB, Needleman L, Wapner RJ , et al. Usefulness of a short femur in the in utero detection of skeletal dysplasias. Radiology 1990; 177: 197-200
• 7 Parilla BV, Leeth EA, Kambich MP, Chilis P, MacGregor SN. Antenatal detection of skeletal dysplasias. J Ultrasound Med 2003; 22: 255-258 , quiz 259–261
• 8 Nyberg DA, Resta RG, Luthy DA, Hickok DE, Williams MA. Humerus and femur length shortening in the detection of Down's syndrome. Am J Obstet Gynecol 1993; 168: 534-538
• 9 Nyberg DA, Luthy DA, Resta RG, Nyberg BC, Williams MA. Age-adjusted ultrasound risk assessment for fetal Down's syndrome during the second trimester: description of the method and analysis of 142 cases. Ultrasound Obstet Gynecol 1998; 12: 8-14
• 10 Weisz B, David AL, Chitty L , et al. Association of isolated short femur in the mid-trimester fetus with perinatal outcome. Ultrasound Obstet Gynecol 2008; 31: 512-516
• 11 Todros T, Massarenti I, Gaglioti P, Biolcati M, Botta G, De Felice C. Fetal short femur length in the second trimester and the outcome of pregnancy. BJOG 2004; 111: 83-85