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6B Smoking During Pregnancy

Description | Specific Indicators | Ontario Public Health Standards | Corresponding Health Indicators from Statistics Canada and CIHI | Corresponding Indicators(s) from Other SourcesData Sources |  Alternative Data Sources |  Analysis Check List | Method of Calculation |  Basic Categories | Indicator Comments | Cross-References to Other Indicators | Cited References  | Changes Made  | Acknowledgements

  • Proportion of pregnant females that smoked cigarettes during pregnancy.
Specific Indicators
  • The number of females who smoked cigarettes during pregnancy as a percentage of the total number of females who gave birth (live birth or stillbirth) in a given place and time.
Ontario Public Health Standards (OPHS)

The Ontario Public Health Standards (OPHS) establish requirements for the fundamental public health programs and services carried out by boards of health, which include assessment and surveillance, health promotion and policy development, disease and injury prevention, and health protection. The OPHS consist of one Foundational Standard and 13 Program Standards that articulate broad societal goals that result from the activities undertaken by boards of health and many others, including community partners, non-governmental organizations, and governmental bodies. These results have been expressed in terms of two levels of outcomes: societal outcomes and board of health outcomes. Societal outcomes entail changes in health status, organizations, systems, norms, policies, environments, and practices and result from the work of many sectors of society, including boards of health, for the improvement of the overall health of the population. Board of health outcomes are the results of endeavours by boards of health and often focus on changes in awareness, knowledge, attitudes, skills, practices, environments, and policies. Boards of health are accountable for these outcomes. The standards also outline the requirements that boards of health must implement to achieve the stated results.


Outcomes Related to this Indicator
  • Board of Health Outcome (Reproductive Health): The board of health is aware of and uses epidemiology to influence the development of healthy public policy and its programs and services for the promotion of reproductive health.
  • Board of Health Outcome (Foundational Standard): The public, community partners, and health care providers are aware of relevant and current population health information.


Assessment and Surveillance Requirements Related to this Indicator (Reproductive Health) 
  • The board of health shall conduct epidemiological analysis of surveillance data... in the area of reproductive health outcomes.

Corresponding Health Indicator(s) from Statistics Canada and CIHI

  • None
Corresponding Indicator(s) from Other Sources
  • None
Data Sources (see Resources: Data Sources) 

Numerator & Denominator: BORN Information System

Original source: Better Outcomes Registry Network (BORN) Ontario
Distributed by: Better Outcomes Registry Network (BORN) Ontario
Suggested citation (see Data Citation Notes): BORN Information System [years], Date Extracted: [date].


Alternative Data Sources
  • None 
Survey Questions 

Data Source

Data Element*

Response Categories




Self-reported smoking during pregnancy

0) Not entered
1) No smoking
2) <= 20 weeks
3) >20 weeks
4) <=20 and >20 weeks
9) Unknown

2001 -March 31, 2012


*From the former Niday Perinatal Database.
Year data were first available varies by health unit.


Analysis Check List
  • Niday Perinatal data is available from BORN upon request.
  • For analysis, create response categories
    • No (variable = 1)
    • Yes (variable = 2 or 3 or 4)
    • Unknown (variable = 0 or 9)
  • The percent of 'unknown' will vary across public health units, making comparisons difficult. Keep 'unknown' as a separate category initially to determine if it can be excluded.
  • Public Health Units access the BORN data through public health reports or data cubes.
  • Refer to the BORN Information System resource for more information about the data.

Method of Calculation

Proportion of females that smoked during pregnancy

Number of pregnant females that smoked cigarettes at any time during their pregnancy

x 100

Total number of females that gave birth (live birth or stillbirth)


Basic Categories
  • Geographic areas of patient residence: Ontario, public health unit
Indicator Comments
  • In the Niday Perinatal Database, the percent of non-response or "unknown" was high in some jursidictions. As a result, Niday made the "Smoking During Pregnancy" field mandatory in January 2009 which led to more complete data (1).The Niday, smoking during pregnancy data element is often recoded to "smoker" and "non-smoker". With the creation of the new BORN database in fall 2011, the indicator was changed to a binary variable.
  • Historical data from the Niday Perinatal Database varies by geographical area. Please refer to the Reproductive Health Core Indicators Documentation Report for details.
  • The data elements captured in the BORN Information System implemented in 2012 are different from the historic Niday Perinatal data and will not be comparable. The new BORN data elements quantify the amount smoked by the mother (M0020-1 and D0005) and determine exposure to second-hand smoke in the home (M0020-2 and D0010) at first prenatal visit and time of newborn's birth respectively.
  • For CCHS data, it is anticipated the sample size will be extremely small and analysis will occur at a larger area than the health unit.
  • The CCHS provides smoking during pregnancy data, asked of females 15 to 55 years old who gave birth in the past 5 years, in the ‘Breastfeeding module' (BRFA -cycle 1.1, 2000/2001); ‘Maternal Experiences' module (MEX - cycles 2.1 (2003), 3.1 (2005)) and ‘Maternal Experiences, Smoking' module (MXS, 2007 - 2010). Please refer to CCHS data dictionaries for details.
  •  Smoking in pregnancy increases the risk to the fetus of: (2-8)
    • intrauterine growth restriction (IUGR)
    • low birth weight
    • preterm birth
    • spontaneous abortion
    • placental complications
    • stillbirth
    • sudden infant death syndrome (SIDS)
    • childhood asthma and respiratory illness
    • neurodevelopmental and behavioural problems
    • some childhood cancers
  • Some of the long-term health impacts for the babies born to females who smoke during pregnancy are a consequence of the perinatal complications they experience such as preterm birth and intrauterine growth restriction (8).
  • Measurement issues are complicated by cessation of use during pregnancy as well as social desirability effects.
Cross-References to Other Indicators
Cited References
  1. BORN Ontario. Perinatal Health Report 2008, May 2010. Available from: Accessed: August 25, 2011.
  2. Cnattingius S. The epidemiology of smoking during pregnancy: Smoking prevalence, maternal characteristics, and pregnancy outcomes. Nicotine & Tobacco Research. 2004;6(Suppl 2):S125-140.
  3. Greaves L, Cormier R, Devries K, Bottorff J, Johnson J, Kirkland S, et al. A best practices review of smoking cessation interventions for pregnant and postpartum girls and women. Vancouver: British Columbia Centre of Excellence for Women‘s Health, 2003 [cited 17 Nov 2009]. Available from:
  4. Haberg SE, Stigum H, Nystad W, Nafstad P. Effects of pre- and postnatal exposure to parental smoking on early childhood respiratory health. American Journal of Epidemiology. 2007;166(6):679-86.
  5. Lannerö E, Wickman M, Pershagen G, Nordvall SL. Maternal smoking during pregnancy increases the risk of recurrent wheezing during the first years of life. Respiratory Research. 2006:7(1):3.
  6. Danielsson J, De Boer M, Petermann F, Daseking M. Nicotine exposure during pregnancy - impact on cognitive development in preschool age[Nikotinexposition in der Schwangerschaft - Auswirkungen auf die kognitive Entwicklung im Kindergartenalter]. Geburtshilfe und Frauenheilkunde. 2009;69(8):692-7.
  7. Ng SP, Zelikoff JT. Smoking during pregnancy: subsequent effects on offspring immune competence and disease vulnerability in later life. Reproductive Toxicology. 2007;23(3):428-37.
  8. Lee S, Armson A. Consensus statement on healthy mothers-healthy babies: How to prevent low birth weight. International Journal of Technology Assessment in Health Care. 2007;23(4):505-14.
Changes Made


Type of Review-Formal Review or Ad Hoc?

Changes made by


April 27, 2004



  • Indicator completed on the website.

June 22, 2012 - January 16, 2013

Formal review

Reproductive Health Sub-Group

  • Changed the data source to Niday Perinatal Database (available through the BORN Information System) from CCHS.
  • Updated indicator comments and cited references.



Lead Authors 

  • Amira Ali, Ottawa Public Health
  • Natalie Greenidge, Public Health Ontario
  • Oren Jalon
  • Enayetur Raheem, Windsor Essex County Health Unit

Contributing Authors

  • Reproductive Health Work Group


  • Michael Chaiton, Centre for Addiction and Mental Health
  • Carmen Yue, Toronto Public Health
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