Association between Congenital Anomalies and Area-Level Deprivation among Infants in Neonatal Intensive Care Units

Abstract

Objective To examine the relationship between area-level material deprivation and the risk of congenital anomalies in infants admitted to neonatal intensive care units (NICUs) across Canada.

Study Design The Canadian Neonatal Network database was used to identify admitted infants who had congenital anomalies between 2005 and 2009. The association between congenital anomalies and material deprivation quintile was assessed using logistic regression analysis.

Results Of 55,961 infants admitted to participating NICUs during the study period, 6002 (10.7%) had major, 6244 (11.2%) had minor, and 43,715 (78.1%) had no anomalies. There were higher odds of major anomalies (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.03 to 1.24) but not minor anomalies (OR 1.01, 95% CI 0.93 to 1.11) in the highest-deprivation areas as compared with the lowest-deprivation area of maternal residence. Analyses of groups of major anomalies revealed higher odds for chromosomal (OR 1.48, 95% CI 1.05 to 2.10) and multiple-systems (OR 1.40, 95% CI 1.14 to 1.71) anomalies in the highest-deprivation areas compared with the lowest-deprivation areas.

Conclusion There are socioeconomic inequalities in the risk of major congenital anomalies, especially chromosomal and multiple-systems anomalies, in the NICU population with the highest rates in the most socioeconomically deprived areas.

Keywords

inequalities - socioeconomic - infant - congenital anomaly

• References

• 1 Synnes AR, Berry M, Jones H, Pendray M, Stewart S, Lee SK. Canadian Neonatal Network. Infants with congenital anomalies admitted to neonatal intensive care units. Am J Perinatol 2004; 21: 199-207
• 2 Lindower JB, Atherton HD, Kotagal UR. Outcomes and resource utilization for newborns with major congenital malformations: the initial NICU admission. J Perinatol 1999; 19: 212-215
• 3 Smith LK, Budd JL, Field DJ, Draper ES. Socioeconomic inequalities in outcome of pregnancy and neonatal mortality associated with congenital anomalies: population based study. BMJ 2011; 343: d4306
• 4 Vrijheid M, Dolk H, Stone D, Abramsky L, Alberman E, Scott JE. Socioeconomic inequalities in risk of congenital anomaly. Arch Dis Child 2000; 82: 349-352
• 5 Carmichael SL, Ma C, Shaw GM. Socioeconomic measures, orofacial clefts, and conotruncal heart defects in California. Birth Defects Res A Clin Mol Teratol 2009; 85: 850-857
• 6 Dolk H, Busby A, Armstrong BG, Walls PH. Geographical variation in anophthalmia and microphthalmia in England, 1988-94. BMJ 1998; 317: 905-909 ; discussion 910
• 7 Liu N, Wen SW, Katherine W, Bottomley J, Yang Q, Walker MC. Neighbourhood family income and adverse birth outcomes among singleton deliveries. J Obstet Gynaecol Can 2010; 32: 1042-1048
• 8 Stone DH, Womersley J. Distribution of congenital anomalies within a city: associations with housing type. Eur J Epidemiol 1989; 5: 255
• 9 Tuohy PG, Counsell AM, Geddis DC. The Plunket National Child Health Study: birth defects and sociodemographic factors. N Z Med J 1993; 106: 489-492
• 10 Damiano P, Tyler M, Romitti PA , et al. Demographic characteristics, care, and outcomes for children with oral clefts in three states using participants from the National Birth Defects Prevention Study. Cleft Palate Craniofac J 2009; 46: 575-582
• 11 Grewal J, Carmichael SL, Song J, Shaw GM. Neural tube defects: an analysis of neighbourhood- and individual-level socio-economic characteristics. Paediatr Perinat Epidemiol 2009; 23: 116-124
• 12 Olsen J, Frische G. Social differences in reproductive health. A study on birth weight, stillbirths and congenital malformations in Denmark. Scand J Soc Med 1993; 21: 90-97
• 13 Varela MM, Nohr EA, Llopis-González A, Andersen AM, Olsen J. Socio-occupational status and congenital anomalies. Eur J Public Health 2009; 19: 161-167
• 14 Lee SK, McMillan DD, Ohlsson A , et al. Variations in practice and outcomes in the Canadian NICU network: 1996–1997. Pediatrics 2000; 106: 1070-1079
• 15 WHO International Classification of Diseases. 9th revision. Geneva, Switzerland: WHO; 1975
• 16 Arbour LT, Beking K, Le ND , et al. Rates of congenital anomalies and other adverse birth outcomes in an offspring cohort of registered nurses from British Columbia, Canada. Can J Public Health 2010; 101: 230-234
• 17 British Columbia Vital Statistics Agency. Health Status Registry Report 2005. Victoria, BC: British Columbia Vital Statistics Agency, Ministry of Health; 2005
• 18 Kramer MS, Platt RW, Wen SW , et al; Fetal/Infant Health Study Group of the Canadian Perinatal Surveillance System. A new and improved population-based Canadian reference for birth weight for gestational age. Pediatrics 2001; 108: E35
• 19 Richardson DK, Corcoran JD, Escobar GJ, Lee SK. SNAP-II and SNAPPE-II: Simplified newborn illness severity and mortality risk scores. J Pediatr 2001; 138: 92-100
• 20 Canadian Institute for Health Information. Reducing Gaps in Health: A Focus on Socio-Economic Status in Urban Canada. Ottawa, ON: CIHI; 2008
• 21 Pampalon R, Raymond G. A deprivation index for health and welfare planning in Quebec. Chronic Dis Can 2000; 21: 104-113
• 22 Wilkins R. Automated Geographic Coding Based on the Statistics Canada Postal Code Conversion File. Cat. no. 82F0086-XDB. Ottawa, ON: Statistics Canada; 2007
• 23 Armitage P. Tests for linear trends in proportions and frequencies. Biometrics 1955; 11: 375-386
• 24 Cochran WG. Some methods of strengthening the common x ² tests. Biometrics 1954; 10: 417-451
• 25 Mantel N, Haenszel W. Statistical aspects of the analysis of data from retrospective studies of disease. J Natl Cancer Inst 1959; 22: 719-748
• 26 Yang J, Carmichael SL, Canfield M, Song J, Shaw GM. National Birth Defects Prevention Study. Socioeconomic status in relation to selected birth defects in a large multicentered US case-control study. Am J Epidemiol 2008; 167: 145-154
• 27 Dolk H, de Wals P. Congenital anomalies. In: Elliott P, Cuzick J, English D, Stern R, , eds. Geographical and Environmental Epidemiology: Methods for Small Area Studies. Oxford, UK: Oxford University Press; 1992: 72-88
• 28 Joseph KS, Liston RM, Dodds L, Dahlgren L, Allen AC. Socioeconomic status and perinatal outcomes in a setting with universal access to essential health care services. CMAJ 2007; 177: 583-590
• 29 Luo ZC, Wilkins R, Kramer MS. Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System. Effect of neighbourhood income and maternal education on birth outcomes: a population-based study. CMAJ 2006; 174: 1415-1420