Abstract
Introduction
The extant literature has examined social inequalities in high-risk categories of birth weight and gestational age (i.e., low birth weight and preterm birth) with little attention given to their distributional nature. As such, a scoping review was conducted to understand how researchers have conceptualized and analyzed socioeconomic inequalities in entire distributions of these birth outcomes.
Methods
Bibliographic databases were searched from their inception until August 2016 for articles from five similar, English-speaking, advanced capitalist democracies: Canada, United States, United Kingdom, Australia and New Zealand.
Results
Twenty-one studies were included in the review, all of which provided rationales for examining socioeconomic inequalities in the entire distribution of birth weight. Yet, only three studies examined non-uniform associations of socioeconomic factors across the distribution of birth weight using conditional quantile regression, while the majority focused on mean birth weight using descriptive analysis or linear regression to analyze inequalities. Nevertheless, study results indicated that socioeconomic inequalities exist throughout the distribution of birth weight, extending beyond the high-risk category of low birth weight.
Discussion
Although social inequalities in distributions of birth weight have been conceptualized, few studies have analytically engaged with this concept. As such, this review supports further investigation of distributional inequalities in birth outcomes using methodology which allows one to empirically quantify and explain differences in population risk distributions, rather than solely between infants born low birth weight or preterm birth, versus not.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abrevaya, J. (2001). The effects of demographics and maternal behavior on the distribution of birth outcomes. Empirical Economics,26(1), 247–257. https://doi.org/10.1007/s001810000052.
Abrevaya, J., & Dahl, C. M. (2008). The effects of birth inputs on birthweight. Journal of Business & Economic Statistics,26(4), 379–397. https://doi.org/10.1198/073500107000000269.
Arksey, H., & O’Malley, L. (2005). Scoping studies: Towards a methodological framework. International Journal of Social Research Methodology,8(1), 19–32. https://doi.org/10.1080/1364557032000119616.
Bartley, M., Power, C., Blane, D., Smith, G. D., & Shipley, M. (1994). Birth weight and later socioeconomic disadvantage: Evidence from the 1958 British cohort study. BMJ,309(6967), 1475–1478.
Baruffi, G., Kieffer, E. C., Alexander, G. R., & Mor, J. M. (1999). Changing pregnancy outcomes of Samoan women in Hawaii. Paediatric and Perinatal Epidemiology,13(3), 254–268.
Basu, S., Hong, A., & Siddiqi, A. (2015). Using decomposition analysis to identify modifiable racial disparities in the distribution of blood pressure in the United States. American Journal of Epidemiology,182(4), 345–353. https://doi.org/10.1093/aje/kwv079.
Bitler, M. P., & Currie, J. (2005). Does WIC work? The effects of WIC on pregnancy and birth outcomes. Journal of Policy Analysis & Management,24(1), 73–91.
Blinder, A. S. (1973). Wage discrimination: Reduced form and structural estimates. The Journal of human resources,8(4), 436–455. https://doi.org/10.2307/144855.
Blumenshine, P., Egerter, S., Barclay, C. J., Cubbin, C., & Braveman, P. A. (2010). Socioeconomic disparities in adverse birth outcomes: A systematic review. American Journal of Preventive Medicine,39(3), 263–272. https://doi.org/10.1016/j.amepre.2010.05.012.
Buka, S. L., Brennan, R. T., Rich-Edwards, J. W., Raudenbush, S. W., & Earls, F. (2003). Neighborhood support and the birth weight of urban infants. American Journal of Epidemiology,157(1), 1–8.
Cogswell, M. E., & Yip, R. (1995). The influence of fetal and maternal factors on the distribution of birthweight. Seminars in Perinatology,19(3), 222–240.
Cole, T. J., Donnet, M. L., & Stanfield, J. P. (1983). Unemployment, birthweight, and growth in the first year. Archives of Disease in Childhood,58(9), 717–721.
DiNardo, J., Fortin, N. M., & Lemieux, T. (1995). Labor market institutions and the distribution of wages, 1973-1992: A semiparametric approach. National bureau of economic research.
Fairley, L. (2005). Changing patterns of inequality in birthweight and its determinants: A population-based study, Scotland 1980-2000. Paediatric and Perinatal Epidemiology,19(5), 342–351. https://doi.org/10.1111/j.1365-3016.2005.00665.x.
Firpo, S., Fortin, N. M., & Lemieux, T. (2009). Unconditional quantile regressions. Econometrica, 77(3), 953–973.
Gage, T. B., Fang, F., O’Neill, E., & Dirienzo, G. (2013). Maternal education, birth weight, and infant mortality in the United States. Demography,50(2), 615–635. https://doi.org/10.1007/s13524-012-0148-2.
Holland, M. L., Kitzman, H., & Veazie, P. (2009). The effects of stress on birth weight in low-income, unmarried black women. Womens Health Issues,19(6), 390–397. https://doi.org/10.1016/j.whi.2009.07.005.
Huang, J. Y., Gavin, A. R., Richardson, T. S., Rowhani-Rahbar, A., Siscovick, D. S., & Enquobahrie, D. A. (2015). Are early-life socioeconomic conditions directly related to birth outcomes? Grandmaternal education, grandchild birth weight, and associated bias analyses. American Journal of Epidemiology,182(7), 568–578. https://doi.org/10.1093/aje/kwv148.
Law, C. M., Barker, D. J. P., Richardson, W. W., Shiell, A. W., Grime, L. P., Armand-Smith, N. G., et al. (1993). Thinness at birth in a northern industrial town. Journal of Epidemiology and Community Health,47(4), 255–259.
Madkour, A. S., Harville, E. W., & Xie, Y. (2014). Neighborhood disadvantage, racial concentration and the birthweight of infants born to adolescent mothers. Maternal and Child Health Journal,18(3), 663–671. https://doi.org/10.1007/s10995-013-1291-0.
Margerison-Zilko, C. E., & Ahern, J. (2010). Exposure to economic contractions and birth outcomes. American Journal of Epidemiology,171, S43.
McGovern, M. E. (2013). Still unequal at birth: Birth weight, socio-economic status and outcomes at age 9. Economic and Social Review,44(1), 53–84.
Ministry of Health. (2013). Table 38: Number and percentage of babies, by birthweight group, and the average birthweight.
Mustard, C. A., & Roos, N. P. (1994). The relationship of prenatal care and pregnancy complications to birthweight in Winnipeg, Canada. American Journal of Public Health,84(9), 1450–1457.
Pearl, M., Braveman, P., & Abrams, B. (2001). The relationship of neighborhood socioeconomic characteristics to birthweight among 5 ethnic groups in California. American Journal of Public Health,91(11), 1808–1814.
Phelan, J. C., Link, B. G., & Tehranifar, P. (2010). Social conditions as fundamental causes of health inequalities: Theory, evidence, and policy implications. Journal of Health and Social Behavior,51(Suppl), S28–S40. https://doi.org/10.1177/0022146510383498.
Rabkin, C. S., Anderson, H. R., Bland, J. M., Brooke, O. G., Chamberlain, G., & Peacock, J. L. (1990). Maternal activity and birth weight: A prospective, population-based study. American Journal of Epidemiology,131(3), 522–531.
Rodriguez-Caro, A., Vallejo-Torres, L., & Lopez-Valcarcel, B. (2016). Unconditional quantile regressions to determine the social gradient of obesity in Spain 1993–2014. International Journal for Equity in Health,15(1), 175. https://doi.org/10.1186/s12939-016-0454-1.
Rose, G. (2001). Sick individuals and sick populations. International Journal of Epidemiology,30(3), 427–432. https://doi.org/10.1093/ije/30.3.427.
Siddiqi, A., Shahidi, F. V., Hildebrand, V., Hong, A., & Basu, S. (2018). Illustrating a ‘consequential’ shift in the study of health inequalities: A decomposition of racial differences in the distribution of body mass. Annals of Epidemiology. https://doi.org/10.1016/j.annepidem.2018.02.003.
Spencer, N. (2004). Accounting for the social disparity in birth weight: Results from an intergenerational cohort. Journal of Epidemiology and Community Health,58(5), 418–419.
Strully, K. W., Rehkopf, D. H., & Xuan, Z. (2010). Effects of prenatal poverty on infant health: State earned income tax credits and birth weight. American Sociological Review,75(4), 534–562. https://doi.org/10.1177/0003122410374086.
Welfare, A. I. O. H. A. (2013). Table 3.5: Births, by gestational age and birth status. In: Australian Government.
Wright, C. M., & Parker, L. (2004). Forty years on: The effect of deprivation on growth in two Newcastle birth cohorts. International Journal of Epidemiology,33(1), 147–152.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Ramraj, C., Pulver, A., O’Campo, P. et al. A Scoping Review of Socioeconomic Inequalities in Distributions of Birth Outcomes: Through a Conceptual and Methodological Lens. Matern Child Health J 24, 144–152 (2020). https://doi.org/10.1007/s10995-019-02838-w
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10995-019-02838-w