European Journal of Epidemiology

, Volume 18, Issue 3, pp 235–243 | Cite as

Risk factors for low birth weight in a socio-economically disadvantaged population: Parity, marital status, ethnicity and cigarette smoking

  • H. Phung
  • A. Bauman
  • T.V. Nguyen
  • L. Young
  • M. Tran
  • K. Hillman


Low birth weight (LBW) is a public health problem, because it is associated with increased risk of morbidity and mortality. The principal aim of this study was to assess risk factors for LBW in a large multi-ethnic and socio-economically disadvantaged population. Data from 3242 mothers, who attended the Well Baby Clinic (Southwestern Sydney, Australia) for the first time, were analysed in relation to their demographic characteristics and socio-economic indices. The overall birthweight was 3377 ± 577 g (mean ± SD). In multiple linear regression analysis, smoking during pregnancy, marital status, parity, and country of birth were independently associated with birth weight. According to this analysis, lower birth weight was associated with mothers who had smoked during pregnancy (by 215.2 ± 18.6 g), who were single (46.9 ± 21 g), and of Asian background (108.5 ± 38.2 g). However, higher parity was associated with significantly higher birth weight. The presence of each factor was coded as 1 and the absence, 0. A ‘risk score’ was then derived by summing up the individual scores. When birth weight was classified as ‘low birth weight’ (defined as those with birth weight being less than 2500 g) or normal birth weight, the overall prevalence of LBW was 1.9%. Each unit increase in the risk score was associated with a 1.9-fold (95% confidence interval: 1.5–2.6) increase in the risk of LBW. These data suggest that apart from marital status, ethnicity and parity, maternal smoking is the single most important preventable risk factors for LBW.

Ethnicity Low birth weight Marital status Parity Smoking during pregnancy Socio-economic status 


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  1. 1.
    Kleinman JC, Madans JH. The effects of maternal smoking, physical stature, and educational attainment on the incidence of low birth weight. Am J Epidemiol 1985; 121: 843–855.Google Scholar
  2. 2.
    Rush D, Cassano P. Relationship of cigarette smoking and social class to birth weight and perinatal mortality among all births in Britain, 5-11 April 1970. J Epidemiol Commun. Health 1983; 37: 249–255.Google Scholar
  3. 3.
    Fuentes-Afflick E, Hessol NA. Impact of Asian ethnicity and national origin on infant birth weight. Am J Epidemiol 1997 15; 145: 148–155.Google Scholar
  4. 4.
    Shiono PH, Klebanoff MA, Graubard BI, Berendes HW, Rhoads GG. Birth weight among women of different ethnic groups. JAMA 1986; 255: 48–52.Google Scholar
  5. 5.
    Phung H, Young L, Greenfield D, Bauman A, Hillman K. A frame work for monitoring maternal and child health status. Aust Health Rev 2001; 24: 105–115.Google Scholar
  6. 6.
    Socio-Economic Index For Area, 1996. Cat No. 2033. 0.30.001, Australia Bureau of Statistic Commonwealth of Australia, 1998.Google Scholar
  7. 7.
    Harrell FE, Califf RM, Pryor DB, Rosati RA. Evaluating the yield of medical tests. JAMA 1982; 247: 2543–2546.Google Scholar
  8. 8.
    Hanley JA, McNeil BJ. The meaning and use of the area under a receiving operating characteristic (ROC) curve. Radiology 1982; 50: 23–36.Google Scholar
  9. 9.
    SAS Institute Inc. SAS/STAT: User's Guides, Release 6.03. Cary, NC: SAS Institute Inc., 1990; 549–640.Google Scholar
  10. 10.
    Hack M, Taylor G, Klein N, Eiben R, Schatschneider C, Mercuri-Munich N. School-age outcomes in children with birth weight under 750 g. New Engl J Med 1994; 331: 753–759.Google Scholar
  11. 11.
    Saigal S, Feeny D, Furlong W, Rosenbaum P, Burrows E, Torrance G. Comparison of the health-related quality of life of extremely low birthweight children and a reference group of children at age 8 years. J Pediatr 1994; 125: 418–425.Google Scholar
  12. 12.
    Kleinman J, Kessel S. Racial differences in low birth-weight: Trends and risk factors. N Engl J Med 1987; 317: 749–753.Google Scholar
  13. 13.
    Frank P, McNamee R, Hannaford PC, Kay CR. Effect of changes in maternal smoking habits in early pregnancy on infant birthweight. Br J Gen Pract 1994; 44: 57–59.Google Scholar
  14. 14.
    Hebel J, Fox N, Sexton M. Dose-response of birth weight to various measures of maternal smoking during pregnancy. J Clin Epidemiol 1988; 41: 483–489.Google Scholar
  15. 15.
    Brooke O, Anderson H, Blard J, Peacock J, Stewart M. Effects of birth weight of smoking, alcohol, caffeine, socioeconomic factors, and psychosocial stress. Br Med J 1989; 298: 795–801.Google Scholar
  16. 16.
    Lieberman E, Gremy I, Lang JM, Cohen AP. Low birthweight at term and the timing of fetal exposure to maternal smoking. Am J Public Health 1994; 84: 1127–1131.Google Scholar
  17. 17.
    Cnattingius S, Granath F, Petersson G, Harlow BL. The influence of gestational age and smoking habits on the risk of subsequent preterm deliveries. N Engl J Med 1999 23; 341: 943–948.Google Scholar
  18. 18.
    Harlow BL, Frigoletto FD, Cramer DW, Evans JK, LeFevre ML, Bain RP. Determinants of preterm delivery in low-risk pregnancies. J Clin Epidemiol 1996; 49: 441–448.Google Scholar
  19. 19.
    Heffner LJ, Sherman CB, Speizer FE, Weiss ST. Clinical and environmental predictors of preterm labor. Obstet Gynecol 1993; 81: 750–757.Google Scholar
  20. 20.
    Andres RL. The association of cigarette smoking with placenta previa and apruptio placentae. Seminars Perinatol 1996; 20: 154–159.Google Scholar
  21. 21.
    Petridou E, Panagiotopoulou K, Katsouyanni K, Spanos E, Trichopoulus D. Tobacco smoking, pregnancy estrogens and birth weight. Epidemiology 1990; 1: 247–250.Google Scholar
  22. 22.
    Ellard GA, Johnstone FD, Prescott RJ, Ji-Xian W, Jian-Hua M. Smoking during pregnancy: The dose dependence of birthweight deficits. Br J Obstet Gynaecol 1996; 103: 806–813.Google Scholar
  23. 23.
    Ahmed F. Unmarried mothers as a high-risk group for adverse pregnancy outcomes. J Commun Health 1990; 1: 35–44.Google Scholar
  24. 24.
    Bennett T. Marital status and infant health outcomes. Soc Sci Med 1992; 9: 1179–1187.Google Scholar
  25. 25.
    Ellard GA, Johnstone FD, Prescott RJ, Ji-Xian W, Jian-Hua M. Smoking during pregnancy: The dose dependence of birthweight deficits. Br J Obstet Gynaecol 1996; 103: 806–813.Google Scholar
  26. 26.
    Mathai M, Vijayasri R, Babu S, Jeyaseelan L. Passive maternal smoking and birthweight in a south Indian population. Br J Obstet Gynaecol 1992; 99: 342–343.Google Scholar

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • H. Phung
    • 1
    • 2
  • A. Bauman
    • 2
  • T.V. Nguyen
    • 3
  • L. Young
    • 1
    • 2
  • M. Tran
    • 1
  • K. Hillman
    • 1
    • 2
  1. 1.The Simpson Centre For Health Services ResearchLiverpool Hospital, South Western Sydney Area Health ServicesSydneyAustralia
  2. 2.Faculty of Medicine University of New South WalesSydneyAustralia
  3. 3.Garvan Institute of Medical ResearchSydneyAustralia

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