Download PDF
Am J Perinatol 2018; 35(07): 695-702
DOI: 10.1055/s-0037-1608791
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Effect of Population-Specific Birthweight Curves on Disparities in Perinatal Mortality in Small-for-Gestational Age Pregnancies

Jacob C. Larkin
1   Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
,
Ashley I. Naimi
2   Department of Epidemiology, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania
› Author Affiliations
Funding This project is supported by NIH grant K12HD063087 (J.C.L.).
Further Information

Publication History

24 August 2017

14 October 2017

Publication Date:
13 December 2017 (online)

Also available at
   Permissions and Reprints

Abstract

Objective To determine the effect of adopting sex or race/ethnicity-specific birthweight curves on small-for-gestational age (SGA)-associated mortality rates for specific populations.

Materials and Methods Analyzing 20,095,735 singleton pregnancies, we compared rates of perinatal death associated with SGA in distinct sex and racial/ethnic groups when SGA was defined using nonspecific, sex-specific, and race/ethnicity-specific birthweight curves.

Results With use of a nonspecific birthweight curve, the rate of perinatal death was higher for SGA males (20.4/1,000 [95% confidence interval (CI), 20.1, 20.7]) than SGA females [14.6/1,000 (95% CI, 14.4, 14.8)]. With a sex-specific curve, this disparity was reduced, measuring 17.7/1,000 (95% CI, 17.4, 17.9) for SGA males and 16.3/1,000 (95% CI, 16.1, 16.6) for females. Using a nonspecific birthweight curve, perinatal death rates were higher for non-Hispanic blacks (20.4/1,000 [95% CI, 20.0, 20.8]) than for all other racial/ethnic groups (15.9/1,000 [95% CI, 15.7, 16.1]). This difference increased with use of a race-specific birthweight curve: perinatal mortality was 29.7/1,000 (95% CI, 29.0, 30.3) for SGA blacks and 14.7/1,000 (95% CI, 14.6, 14.9) for all other racial/ethnic groups.

Conclusion Population-based differences in SGA-associated mortality are reduced with adoption of a sex-specific birthweight curve, but widen with use of a race/ethnicity-specific curve. These findings highlight the importance of outcomes analysis in the selection of diagnostic criteria for SGA.

Keywords

fetal growth restriction - small for gestational age - neonatal mortality - stillbirth - perinatal mortality - racial disparities

Supplementary Material

 

  • References

  • 1 Resnik R. Intrauterine growth restriction. Obstet Gynecol 2002; 99 (03) 490-496
    PubMedSearch in Google Scholar
  • 2 Barker DJ. Fetal growth and adult disease. Br J Obstet Gynaecol 1992; 99 (04) 275-276
    CrossrefPubMedSearch in Google Scholar
  • 3 American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 134: fetal growth restriction. Obstet Gynecol 2013; 121 (05) 1122-1133
    CrossrefPubMedSearch in Google Scholar
  • 4 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
    CrossrefPubMedSearch in Google Scholar
  • 5 Fenton TR. A new growth chart for preterm babies: Babson and Benda's chart updated with recent data and a new format. BMC Pediatr 2003; 3: 13
    CrossrefPubMedSearch in Google Scholar
  • 6 Duryea EL, Hawkins JS, McIntire DD, Casey BM, Leveno KJ. A revised birth weight reference for the United States. Obstet Gynecol 2014; 124 (01) 16-22
    CrossrefPubMedSearch in Google Scholar
  • 7 Buck Louis GM, Grewal J, Albert PS. , et al. Racial/ethnic standards for fetal growth: the NICHD Fetal Growth Studies. Am J Obstet Gynecol 2015; 213 (04) 449.e1-449.e41
    CrossrefPubMedSearch in Google Scholar
  • 8 Gardosi J, Francis A. A customized standard to assess fetal growth in a US population. Am J Obstet Gynecol 2009; 201 (01) 25.e1-25.e7
    CrossrefPubMedSearch in Google Scholar
  • 9 Hadlock FP, Harrist RB, Martinez-Poyer J. In utero analysis of fetal growth: a sonographic weight standard. Radiology 1991; 181 (01) 129-133
    CrossrefPubMedSearch in Google Scholar
  • 10 Villar J, Cheikh Ismail L, Victora CG. , et al; International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st). International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project. Lancet 2014; 384 (9946): 857-868
    CrossrefPubMedSearch in Google Scholar
  • 11 Papageorghiou AT, Ohuma EO, Altman DG. , et al; International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st). International standards for fetal growth based on serial ultrasound measurements: the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. Lancet 2014; 384 (9946): 869-879
    CrossrefPubMedSearch in Google Scholar
  • 12 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 (04) 225-231
    CrossrefPubMedSearch in Google Scholar
  • 13 Parker AJ, Davies P, Mayho AM, Newton JR. The ultrasound estimation of sex-related variations of intrauterine growth. Am J Obstet Gynecol 1984; 149 (06) 665-669
    CrossrefPubMedSearch in Google Scholar
  • 14 Lubchenco LO, Hansman C, Dressler M, Boyd E. Intrauterine growth as estimated from liveborn birth-weight data at 24 to 42 weeks of gestation. Pediatrics 1963; 32: 793-800
    CrossrefPubMedSearch in Google Scholar
  • 15 Trudell AS, Cahill AG, Tuuli MG, Macones GA, Odibo AO. Stillbirth and the small fetus: use of a sex-specific versus a non-sex-specific growth standard. J Perinatol 2015; 35 (08) 566-569
    CrossrefPubMedSearch in Google Scholar
  • 16 Schwärzler P, Bland JM, Holden D, Campbell S, Ville Y. Sex-specific antenatal reference growth charts for uncomplicated singleton pregnancies at 15-40 weeks of gestation. Ultrasound Obstet Gynecol 2004; 23 (01) 23-29
    CrossrefPubMedSearch in Google Scholar
  • 17 Bryant AS, Worjoloh A, Caughey AB, Washington AE. Racial/ethnic disparities in obstetric outcomes and care: prevalence and determinants. Am J Obstet Gynecol 2010; 202 (04) 335-343
    CrossrefPubMedSearch in Google Scholar
  • 18 Grobman WA, Bailit JL, Rice MM. , et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network. Racial and ethnic disparities in maternal morbidity and obstetric care. Obstet Gynecol 2015; 125 (06) 1460-1467
    CrossrefPubMedSearch in Google Scholar
  • 19 Spong CY, Iams J, Goldenberg R, Hauck FR, Willinger M. Disparities in perinatal medicine: preterm birth, stillbirth, and infant mortality. Obstet Gynecol 2011; 117 (04) 948-955
    CrossrefPubMedSearch in Google Scholar
  • 20 Chen HY, Chauhan SP, Rankins NC, Ananth CV, Siddiqui DS, Vintzileos AM. Racial and ethnic disparities in infant mortality in the United States: the role of gestational age. Am J Perinatol 2013; 30 (06) 469-475
    Thieme ConnectPubMedSearch in Google Scholar
  • 21 Osterman MJ, Kochanek KD, MacDorman MF, Strobino DM, Guyer B. Annual summary of vital statistics: 2012-2013. Pediatrics 2015; 135 (06) 1115-1125
    CrossrefPubMedSearch in Google Scholar
  • 22 Kramer MS, Ananth CV, Platt RW, Joseph KS. US Black vs White disparities in foetal growth: physiological or pathological?. Int J Epidemiol 2006; 35 (05) 1187-1195
    CrossrefPubMedSearch in Google Scholar
  • 23 Joseph KS, Wilkins R, Dodds L. , et al. Customized birth weight for gestational age standards: perinatal mortality patterns are consistent with separate standards for males and females but not for blacks and whites. BMC Pregnancy Childbirth 2005; 5 (01) 3
    CrossrefPubMedSearch in Google Scholar
  • 24 Data Access - Vital Statistics Online. In; 2015. Available at http://www.cdc.gov/nchs/data_access/vitalstatsonline.htm
    PubMed
  • 25 American College of Obstetricians and Gynecologists. Practice bulletin no. 146: management of late-term and postterm pregnancies. Obstet Gynecol 2014; 124 (2 Pt 1): 390-396
    CrossrefPubMedSearch in Google Scholar
  • 26 Basso O, Wilcox A. Mortality risk among preterm babies: immaturity versus underlying pathology. Epidemiology 2010; 21 (04) 521-527
    CrossrefPubMedSearch in Google Scholar
  • 27 Talge NM, Mudd LM, Sikorskii A, Basso O. United States birth weight reference corrected for implausible gestational age estimates. Pediatrics 2014; 133 (05) 844-853
    Search in Google Scholar
  • 28 Berkley E, Chauhan SP, Abuhamad A. ; Society for Maternal-Fetal Medicine Publications Committee. Doppler assessment of the fetus with intrauterine growth restriction. Am J Obstet Gynecol 2012; 206 (04) 300-308
    CrossrefPubMedSearch in Google Scholar
  • 29 Ferdynus C, Quantin C, Abrahamowicz M. , et al. Can birth weight standards based on healthy populations improve the identification of small-for-gestational-age newborns at risk of adverse neonatal outcomes?. Pediatrics 2009; 123 (02) 723-730
    CrossrefPubMedSearch in Google Scholar
  • 30 Bernstein IM, Mohs G, Rucquoi M, Badger GJ. Case for hybrid “fetal growth curves”: a population-based estimation of normal fetal size across gestational age. J Matern Fetal Med 1996; 5 (03) 124-127
    PubMedSearch in Google Scholar
  • 31 Cooke RW. Conventional birth weight standards obscure fetal growth restriction in preterm infants. Arch Dis Child Fetal Neonatal Ed 2007; 92 (03) F189-F192
    CrossrefPubMedSearch in Google Scholar
  • 32 Marsál K, Persson PH, Larsen T, Lilja H, Selbing A, Sultan B. Intrauterine growth curves based on ultrasonically estimated foetal weights. Acta Paediatr 1996; 85 (07) 843-848
    CrossrefPubMedSearch in Google Scholar
  • 33 Zaw W, Gagnon R, da Silva O. The risks of adverse neonatal outcome among preterm small for gestational age infants according to neonatal versus fetal growth standards. Pediatrics 2003; 111 (6 Pt 1): 1273-1277
    CrossrefPubMedSearch in Google Scholar
  • 34 Hanley GE, Janssen PA. Ethnicity-specific birthweight distributions improve identification of term newborns at risk for short-term morbidity. Am J Obstet Gynecol 2013; 209 (05) 428.e1-428.e6
    CrossrefPubMedSearch in Google Scholar
  • 35 Kierans WJ, Joseph KS, Luo ZC, Platt R, Wilkins R, Kramer MS. Does one size fit all? The case for ethnic-specific standards of fetal growth. BMC Pregnancy Childbirth 2008; 8: 1
    CrossrefPubMedSearch in Google Scholar