Serial third trimester ultrasound examinations in predicting fetal weight

Abstract

Objective: The aim of this study was to compare the ac­curacy of estimated fetal weights obtained by ultrasonog­raphies performed at different weeks in the third trimester and just before delivery. Methods: A total of 664 patients underwent three serial ultrasonographic examinations in the third trimester. The sonographically estimated fetal weight was calculated us­ing the Hadlock formula and then converted into percen­tiles. The estimated fetal weight percentiles were com­pared with the actual birth weight percentiles at delivery. Results: Mean maternal age was 30±4 years (18-42 years), mean gestational age at first ultrasound was 32±0.5 weeks (30.4-33.6 weeks), mean gestational age at second ultrasound was 36±0.4 weeks (35-36.9 weeks), mean gestational age at third ultrasound was 38.6±1 weeks (36.3– 42 weeks). Mean gestational age at deliv­ery was 39± 1 weeks (36-42 weeks), mean birth weight was 3422±423 grams (1900-4900 grams). Correlation coefficients of estimated fetal weights percentiles at first, second and third ultrasounds were significantly correlated with birth weight percentiles (r=0.556, p

Keywords

• Fetal weight estimation, third trimester ultra­sound, Hadlock formula

Ardışık üçüncü trimester ultrason incelemeleri ile fetal ağırlığın tahmin edilmesi

Öz

Amaç: Bu çalışmanın amacı, üçüncü trimesterin değişik haftalarında ve doğumdan hemen önce yapılan ultraso­nografik ölçümlerin tahmini fetal ağırlığı tespit etmedeki doğruluğunu belirlemektir. Yöntemler: Toplam 664 hastanın üçüncü trimesterde ya­pılmış 3 adet ultrasonografik verisi elde edildi ve Hadlock formülü ile tahmini doğum ağırlığı ve persentili hesaplan­dı. Daha sonra tahmini fetal ağırlık persentilleri, doğum­daki gerçek ağırlık persentili ile karşılaştırıldı. Bulgular: Ortalama anne yaşı 30±4 (18-42) yıl, ilk üçüncü trimester ultrasonunun yapıldığı hafta ortalaması 32±0.5 hafta (30.4-33.6 hafta), ikinci ultrasonun yapıldığı hafta ortalaması 36±0.4 hafta (35-36.9 hafta), üçüncü ultraso­nun yapıldığı hafta ortalaması 38.6±1 hafta (36.3– 42 haf­ta). Doğumun gerçekleştiği ortalama gebelik haftası 39±1 hafta (36-42 hafta), ortalama doğum kilosu 3422±423 gram (1900-4900 gram). Birinci, ikinci, üçüncü ultrason ölçümlerinde elde edilen persentillerin doğum ağırlığı persentili ile korelasyonu (sırasıyla, r=0.556, p

Anahtar Kelimeler

• Tahmini doğum ağırlığı, üçüncü tri­mester ultrasonu, Hadlock

References

1. Heiskanen N, Raatkainen K, Heinonen S. Fetal macro- somia- a continuing obstetric challenge. Biol Neonate 2006;90:98-103.
2. Medchill MT, Peterson CM, Kreinick C, et al. Prediction of estimated fetal weight in extremely low birth weight neonates (500-1000 g). Obstet Gynecol 1991;78:286- 290.
3. Nahum GG, Stanislaw H. Validation of a birth weight prediction equation based on maternal characteris- tics. J Reprod Med 2002;47:752-760.
4. Mongelli M, Benzie R. Ultrasound diagnosis of fetal macrosomia: a comparison of weight prediction mod- els using computer simulation. Ultrasound Obstet Gy- necol 2005;26:500-503.
5. Chauhan SP, Hendrix NW, Magann EF, et al. Limita- tions of clinical and sonographic estimates of birth weight: experience with 1034 parturients. Obstet Gy- necol 1998;91:72-77
6. Halaska MG, Vlk R, Feldmar P, et al. Predicting term birth weight using ultrasound and maternal character- istics. Eur J Obstet Gynecol Biol 2006;128:231-235
7. Pressman EK, Bienstock JL, Blakemore KJ, et al. Pre- diction of birth weight by ultrasound in the third trimes- ter. Obstet Gynecol 2000;95:502-506.
8. Krantz C, Hitschold T. Impact and limitations of ultra- sound examination immediately before delivery-a prospective evaluation with 1127 pregnant women. Z Geburtshilfe Neonatol 2011;215:69-76.

9. Mongelli M, Gardosi J. Gestation-adjusted projection of estimated fetal weight. Acta Obstet Gynecol Scand 1996;75:28-31.
10. Hadlock FP, Harrist RB, Sharman RS, et al. Estima- tion of fetal weight with the use of head, body, and fe- mur measurements: a prospective study. Am J Obstet Gynecol 1985;151:333-337.
11. Dudley NJ. A systematic review of the ultrasound es- timation of fetal weight. Ultrasound Obstet Gynecol 2005;25:80-89.
12. Larsen T, Greisen G, Petersen S. Prediction of birth weight by ultrasound-estimated fetal weight: a com- parison between single and repeated estimates. Eur J Obstet Gynecol Reprod Biol 1995;60:37-40.
13. Ben-Haroush A, Yogev Y, Bar J, et al. Accuracy of so- nographic estimated fetal weight in 840 women with different pregnancy complications prior to induction of labor. Ultrasound Obstet Gynecol 2004;23:172-176.
14. Colman A, Maharaj D, Hutton J, et al. Reliability of ultrasound estimation of fetal weight in term singleton pregnancies. N Z Med J 20068;119:2146-2149.
15. Ben-Haroush A, Yogev Y, Hod M, et al. Predictive value of a single early fetal weight estimete in normal pregnancies. Eur J Obstet Gynecol Biol 2007;130:187- 192.
16. Nelson L, Wharton B, Grobman WA. Prediction of large for gestational age birth weights in diabetic mothers based on early third trimester sonography. J Ultrasound Med 2011;30:1625-1628.
17. Kehl RJ, Krew MA, Thomas A, Catalano PM. Fetal growth and body composition in infants of women with diabetes mellitus during pregnancy J Matern Fetal Med 1996;5:273-280.
18. Blann DW, Prien SD. Estimation of fetal weight before and after amniotomy in the laboring gravid woman. Am J Obstet Gynecol 2000 ;182:1117-1120.
19. Townsend RR, Filly RA,Callen PW, et al. Factors af- fecting prenatal sonographic estimation of weight in extremely low birthweight infants. J Ultrasound Med 1988;7:183-187.
20. Schild RL, Sachs C, Fimmers R, et al. Sex-specific fe- tal weight prediction by ultrasound. Ultrasound Obstet Gynecol 2004;23:30-35.
21. Schwarzler P, Bland JM, Holden D, et al. Sex-specific antenatal reference growth charts for uncomplicated singleton pregnancies at 15-40 weeks of gestation. Ultrasound Obstet Gynecol 2004;23:23-29.
22. McNamara JM, Odibo AO, Macones GA, Cahill AG.The effect of breech presentation on the accuracy of estimated fetal weight. Am J Perinat 2012;29:353- 360.
23. Sanchez- Ramos L, Bernstein S, Kaunitz AM. Expect- ant management versus labor induction for suspected fetal macrosomia: a systematic review. Obstet Gyne- col 2002;100:997-1002.
24. Weiner Z, Ben-Shlomo I, Beck-Fruchter R, et al. Clini- cal and ultrasonographic weight estimation in large for gestational age fetus. Eur J Obstet Reprod Biol 2002;105:20-24.