Epidemiology of alcohol use in pregnancy in Canada

New Data from the Canadian Maternity Experiences Survey

Getting accurate data about alcohol use in pregnancy can be a tricky thing sometimes. There are basically three different ways to learn about alcohol use during pregnancy:  self-report questionnaires and interviews, screening tools, and biomarkers (e.g., hair and  meconium). That said, most information collected on alcohol use in pregnancy is based on self-report data gathered through interviews, self-administered questionnaires and intake histories administered for either clinical or research purposes.

All research methodologies have strengths and weaknesses. Self-report data can often lead to variations in study outcomes. Different questions about alcohol use (e.g., frequency versus amount of alcohol), timing of the survey (e.g., during pregnancy or 1 month or 1 year postpartum), different samples (e.g., national or regional), recall bias, and whether women felt safe to answer questions about a potentially stigmatizing issue are just some of the factors that influence the findings of a research study. Often, the best bet is to take a look at a number of different studies (if available) before drawing any conclusions on what’s happening in the real world.

Here’s a list of major national studies surveying alcohol use in pregnancy:

• Canadian Community Health Survey (CCHS) – The CCHS has been conducted by Statistics Canada every two years since 2000. During the 2007/8 cycle, an additional questionnaire in Ontario and British Columbia asked 3004 women aged 15-55 years who gave birth(s) in last 5 years whether they drank any alcohol during their last pregnancy. When the data was extrapolated to the Canadian population as a whole, the prevalence of drinking alcohol during pregnancy was estimated at 5.8%.
• National Longitudinal Survey of Children and Youth (NLSCY) –  In 1998-99, 14.4% of women reported drinking at some point during their pregnancy, and 4.9% drank throughout.
• National Population Health Survey (NPHS) – The NPHS interviews 17,276 Canadians about a range of health concerns every two years. The 1994-95 cycle found that between 17% and 25% of women drank alcohol at some point during their pregnancy, and between 7% and 9% drank alcohol throughout their pregnancy.

A few weeks ago, a study was published using data from the Canadian Maternity Experience Survey (MES).  The MES is a population-based survey that assessed pregnancy, delivery and postnatal experiences of mothers and their children between November 2005 and May 2006. The survey found that 10.8% of women reported ever drinking alcohol during their pregnancy. As you can see in the table below, rates also varied by region.

For more on ways to improve data collection  and issues with survey data, take a look at the report Research update : Alcohol use and pregnancy : an important Canadian public health and social issue (2006) written by Colleen Dell and Gary Roberts for the Public Health Agency of Canada.

References:

Public Health Agency of Canada. (2006). Research Update – Alcohol Use and Pregnancy: An Important Canadian Public Health and Social Issue . Health Canada Publications, Ottawa.

Thanh, N.X. and Jonsson. (2010). Drinking Alcohol during Pregnancy: Evidence from Canadian Community Health Survey 2007/ 2008. Journal of Population Therapeutics and Clinical Pharmacololgy, 17 (2): e302-e307. Free full-text available.

Walker, M., Al-Sahab, B., Islam, F., & Tamim, H. (2011). The epidemiology of alcohol utilization during pregnancy: an analysis of the Canadian Maternity Experiences Survey (MES). BMC Pregnancy and Childbirth, 11(1), 52. Free full-text available.