The low birth weight rate indicator estimates the rate of singleton live births weighing 500-2499 grams immediately upon birth, based on the mother’s usual place of residence per the total for singleton live births weighing at least 500 grams per 1,000 births.
Low birth weight is considered one of the most important indicators of a newborn’s chances of survival, with low birth weight being a major risk factor for perinatal and infant mortality.30 Low birth weight babies are more likely to have health and developmental problems including learning difficulties, hearing and visual impairments, chronic respiratory problems such as asthma and chronic diseases later in life. 31, 32
Low birth weight is also an important population health indicator as it occurs with greater prevalence in disadvantaged populations. Risk factors associated with low birth weight include:
- socio-economic disadvantage
- poor health and nutrition of women during pregnancy
- smoking while pregnant
- consumption of drugs and alcohol while pregnant
- experiencing abuse while pregnant 33, 34
It has been demonstrated that maternal smoking is one of the most modifiable risk factors to prevent low birth weight babies in developed countries. 35, 36 This underscores the importance of programs and policies to prevent women from becoming smokers and encouraging those who do smoke to quit.
Public health programs and services provide education and resources to women of child bearing age to promote healthy nutrition prior to conception and during pregnancy, provide prenatal education, encourage pregnant women to access prenatal support services, and provide assessments to at-risk pregnant women to help ensure that they receive appropriate medical attention.
Public health interventions also address factors that influence health outcomes such as access to nutritious foods, smoking, substance misuse, and alcohol consumption.
In 2007, the rate of singleton live births in Ontario with a birth weight of less than 2500 grams was 47.9 per 1,000 births. Based on 36 public health units in Ontario, the highest rate of live births weighing under 2500 grams was 67.5 and the lowest rate was 20.9 per 1,000 births.
The low birth weight rate indicator estimates the rate of singleton live births weighing 500-2499 grams immediately upon birth, based on the mother's usual place of residence per the total for singleton live births weighing at least 500 grams per 1,000 births.
||Inpatient Services Provincial Health Planning Database, Ministry of Health and Long-Term Care
||Inpatient Services (Hospital Data), Provincial Health Planning Database, Ministry of Health and Long-Term Care
||Total number of singleton live births weighing between 500 and 2499 grams (2007 calendar year)
Total number of singleton live births weighing at least 500 grams (2007 calendar year)
- Excludes births with weights recorded under 500 grams due to possible entry errors with still born births
- Excludes multiple births
- PHPDB Qualifications: Newborns (entry code=N) at date of admission; Patient Diagnosis Codes (beginning with Z380, Z381, Z382) for the Calendar Year (2007). Weights for singleton live births (greater than or equal to 500); Weights for low births weights (greater than or equal to 500 grams and less than 2500 grams)
- Intellihealth\05 Inpatient Discharges\Hospital Births\ Low Birth Weight, Singleton Births: Report # 05?0004 was used to derive both the numerator and denominator
- The indicator is not limited to full-term births and also includes pre-term births
- Analyzed by mother's usual place of residence, not place of birth
- Excludes births to mothers who reside out of province
30 Core Health Indicators Work Group. Perinatal mortality. In: Core indicators for public health in Ontario. Toronto, ON: Association of Public Health Epidemiologists in Ontario; 2005. Retrieved April 15, 2009 from: http://www.apheo.ca/index.php?pid=145#comments.
31 Cole C, Hagadorn J, Kim C, et al. Criteria for determining disability in infants and children: low birth weight. Evidence report/technology assessment no. 70. Rockville, MD: Agency for Healthcare Research and Quality; 2002. Retrieved April 15, 2009 from: http://www.ahrq.gov/downloads/pub/evidence/pdf/lbw/lbw.pdf.
32 Matsuo, H. The health consequences of low birth weight: literature review and critique. UCL working paper no. 23. Louvain-la-Neuvem, Belgium: l’Université catholique de Louvain; 2005. Retrieved April 14, 2009 from: http://www.uclouvain.be/cps/ucl/doc/sped/documents/dt23.pdf.
33 Canadian Institute of Child Health. Fact sheet: low birth weight. In: The health of Canada’s children: a CICH profile. Ottawa, ON: Canadian Institute of Child Health; 2000. Retrieved April 15, 2009 from: http://www.cich.ca/PDFFiles/ProfileFactSheets/English/LBWEng.pdf.
34 Perinatal Education Program of Eastern Ontario. Factors and interventions associated with low birth weight. In: Prevention of low birth weight in Canada: literature review and strategies. 2nd ed. Toronto, ON: Best Start; 1998. Retrieved April 15, 2009 from: http://www.beststart.org/resources/lbw_aware/pdf/lbw_aware/lbw_rpt/lbw98TOC.html.
35 Almond D, Chay KY, Lee DS. The costs of low birth weight. Quarterly Journal of Economics. 2005. 120(3):1031–1083. Retrieved April 14, 2009 from: http://www.nber.org/~almond/qje_bw_final.pdf.
36 Kramer MS. Intrauterine growth and gestational duration determinants. Pediatrics. 1987;80:502-511.