Population versus Customized Fetal Growth Norms and Adverse Outcomes in an Intrapartum Cohort

Abstract

Objective To compare population versus customized fetal growth norms in identifying neonates at risk for adverse outcomes (APO) associated with small for gestational age (SGA).

Study Design Secondary analysis of an intrapartum fetal pulse oximetry trial in nulliparous women at term. Birth weight percentiles were calculated using ethnicity- and gender-specific population norms and customized norms (Gardosi).

Results Of the studied neonates, 508 (9.9%) and 584 (11.3%) were SGA by population (SGApop) and customized (SGAcust) norms, respectively. SGApop infants were significantly associated with a composite adverse neonatal outcome, neonatal intensive care admission, low fetal oxygen saturation, and reduced risk of cesarean delivery; both SGApop and SGAcust infants were associated with a 5-minute Apgar score < 4. The ability of customized and population birth weight percentiles in predicting APO was poor (12 of 14 APOs had area under the curve of <0.6).

Conclusion In this intrapartum cohort, neither customized nor normalized population norms adequately identified neonates at risk of APO related to SGA.

Keywords

customized norm - fetal growth - small for gestational age - adverse outcomes

Note

Presented in part at the Society for Gynecologic Investigation 58th Annual Scientific Meeting in Miami, FL, March 17 to 19, 2011.

• References

• 1 McIntire DD, Bloom SL, Casey BM, Leveno KJ. Birth weight in relation to morbidity and mortality among newborn infants. N Engl J Med 1999; 340: 1234-1238
• 2 Schoendorf KC, Hogue CJ, Kleinman JC, Rowley D. Mortality among infants of black as compared with white college-educated parents. N Engl J Med 1992; 326: 1522-1526
• 3 Kajantie E, Osmond C, Barker DJ, Forsén T, Phillips DI, Eriksson JG. Size at birth as a predictor of mortality in adulthood: a follow-up of 350 000 person-years. Int J Epidemiol 2005; 34: 655-663
• 4 Barker DJ, Osmond C, Forsén TJ, Kajantie E, Eriksson JG. Trajectories of growth among children who have coronary events as adults. N Engl J Med 2005; 353: 1802-1809
• 5 Ozanne SE, Fernandez-Twinn D, Hales CN. Fetal growth and adult diseases. Semin Perinatol 2004; 28: 81-87
• 6 Alexander GR, Kogan MD, Himes JH. 1994–1996 U.S. singleton birth weight percentiles for gestational age by race, Hispanic origin, and gender. Matern Child Health J 1999; 3: 225-231
• 7 Hadlock FP, Harrist RB, Martinez-Poyer J. In utero analysis of fetal growth: a sonographic weight standard. Radiology 1991; 181: 129-133
• 8 Reeves S, Bernstein IM. Optimal growth modeling. Semin Perinatol 2008; 32: 148-153
• 9 Gardosi J. Customized fetal growth standards: rationale and clinical application. Semin Perinatol 2004; 28: 33-40
• 10 Gardosi J, Chang A, Kalyan B, Sahota D, Symonds EM. Customised antenatal growth charts. Lancet 1992; 339: 283-287
• 11 Gardosi J, Mongelli M, Wilcox M, Chang A. An adjustable fetal weight standard. Ultrasound Obstet Gynecol 1995; 6: 168-174
• 12 Gardosi J, Francis A. A customized standard to assess fetal growth in a US population. Am J Obstet Gynecol 2009; 201: 25 , e1–e7
• 13 GROW. Gestation Related Optimal Weight. Customised growth chart software versions 5.x-7.x, 2000–2009. Available at: Gestation Network, www.gestation.net . Accessed April 20, 2011
• 14 Gardosi J, Francis A. Adverse pregnancy outcome and association with small for gestational age birthweight by customized and population-based percentiles. Am J Obstet Gynecol 2009; 201: 28 , e1–e8
• 15 Bloom SL, Spong CY, Thom E , et al; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Fetal pulse oximetry and cesarean delivery. N Engl J Med 2006; 355: 2195-2202
• 16 McNemar Q. Note on the sampling error of the difference between correlated proportions or percentages. Psychometrika 1947; 12: 153-157
• 17 DeLong ER, DeLong DM, Clarke-Pearson DL. Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparametric approach. Biometrics 1988; 44: 837-845
• 18 Mongelli M, Wilcox M, Gardosi J. Estimating the date of confinement: ultrasonographic biometry versus certain menstrual dates. Am J Obstet Gynecol 1996; 174 (1 Pt 1) 278-281
• 19 de Jong CL, Gardosi J, Dekker GA, Colenbrander GJ, van Geijn HP. Application of a customised birthweight standard in the assessment of perinatal outcome in a high risk population. Br J Obstet Gynaecol 1998; 105: 531-535
• 20 Clausson B, Gardosi J, Francis A, Cnattingius S. Perinatal outcome in SGA births defined by customised versus population-based birthweight standards. BJOG 2001; 108: 830-834
• 21 McCowan LM, Harding JE, Stewart AW. Customized birthweight centiles predict SGA pregnancies with perinatal morbidity. BJOG 2005; 112: 1026-1033
• 22 Mongelli M, Gardosi J. Reduction of false-positive diagnosis of fetal growth restriction by application of customized fetal growth standards. Obstet Gynecol 1996; 88: 844-848
• 23 Ego A, Subtil D, Grange G , et al. Customized versus population-based birth weight standards for identifying growth restricted infants: a French multicenter study. Am J Obstet Gynecol 2006; 194: 1042-1049
• 24 Jacobsson B, Ahlin K, Francis A, Hagberg G, Hagberg H, Gardosi J. Cerebral palsy and restricted growth status at birth: population-based case-control study. BJOG 2008; 115: 1250-1255
• 25 Sciscione AC, Gorman R, Callan NA. Adjustment of birth weight standards for maternal and infant characteristics improves the prediction of outcome in the small-for-gestational-age infant. Am J Obstet Gynecol 1996; 175 (3 Pt 1) 544-547