Transitions in Smoking Across a Pregnancy: New Information from the Growing Up in New Zealand Longitudinal Study
Introduction Maternal smoking remains a modifiable cause of adverse maternal and child health outcomes. This study investigated smoking transitions across pregnancy. Methods Data from the contemporary child cohort study Growing Up in New Zealand (n = 6822) were used to analyse smoking status across three points across a pregnancy: pre-pregnancy, during pregnancy and after pregnancy. Odds-ratios (OR) were calculated for maternal, socio-economic and pregnancy-related factors associated with each transition using multivariate logistic regression. Results The prevalence of smoking pre-pregnancy was 20.3%. The cessation rate during pregnancy was 48.5%, while the postpartum relapse rate was 36.0%. Heavy smokers were less likely to quit during pregnancy (OR 0.13, 95% CI 0.08–0.20), and more likely to relapse at 9 months (OR 2.63, CI 1.60–4.32), relative to light smokers. Women in households with another smoker were less likely to quit during pregnancy (OR 0.35, CI 0.25–0.48), and more likely to relapse postpartum (OR 2.00, CI 1.14–3.51), relative to women in a smoke-free household. Women without high school qualifications were less likely to quit during pregnancy than women with bachelor degrees (OR 0.21, CI 0.11–0.41) but no more likely to relapse. Maori women were less likely to quit during pregnancy than European women (OR 0.35, CI 0.25–0.49) but no more likely to relapse. Conclusion Heavy smokers and those with another smoker in the household are at high risk of smoking during pregnancy or relapsing after pregnancy. Decreasing smoking across a pregnancy therefore requires a focus on cessation in all households with heavy smokers of child-bearing age. The association between smoking and ethnicity may be confounded as it not consistent across the pregnancy.
KeywordsSmoking Pregnancy Postpartum Longitudinal study
We acknowledge the key role of the Ministry of Social Development in identifying the need for a longitudinal study that reflects the diversity of today’s New Zealand and for its ongoing support. Other agencies, as well as The University of Auckland, have contributed to the cost of the study to-date. These are: the Ministry of Health, the New Zealand Police, the Ministry of Justice, the Families Commission, the Children’s Commission, the Department of Labour, the Ministry of Education, Housing New Zealand and Sport and Recreation New Zealand. The funders have had no role in the design, analysis or writing of this article.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no competing interests.
- AIHW (2011). 2010 National Drug Strategy Household Survey report. Drug statistics series no. 25. Cat. no. PHE 145. Canberra: AIHW.Google Scholar
- American College of Obstetricians and Gynecologists (2011). Smoking cessation during pregnancy: A clinician’s guide to helping pregnant women quit smoking.Google Scholar
- Centre for Disease Control (2011). PRAMS online data for epidemiologic research.Google Scholar
- Craig, E., Dell, R., et al. (2012). The determinants of health for children and young people in New Zealand. Dunedin: New Zealand Child and Youth Epidemiology Service, University of Otago.Google Scholar
- Glover, M., & Kira, A. (2011). Why Māori women continue to smoke while pregnant. The New Zealand Medical Journal, 29, 22–31.Google Scholar
- Lumley, J., Chamberlain, C., et al. (2009). Interventions for promoting smoking cessation during pregnancy. The Cochrane database of systematic reviews, 3(3), CD001055.Google Scholar
- Makowharemahihi, C., Lawton, B., et al. (2014). Initiation of maternity care for young Māori women under 20 years of age. The New Zealand Medical Journal, 127, 1393.Google Scholar
- McLeod, D., Pullon, S., et al. (2003). Factors that influence changes in smoking behaviour during pregnancy. The New Zealand Medical Journal 116, 1173.Google Scholar
- Ministry of Health (2013). New Zealand Health Survey 2012/2013.Google Scholar
- Morton, S., Atatoa Carr, P., et al. (2012). Growing Up in New Zealand: A longitudinal study of New Zealand children and their families. Report 2: Now we are born. Auckland.Google Scholar
- Morton, S. M., Atatoa Carr, P., et al. (2010). Growing Up in New Zealand: A longitudinal study of New Zealand children and their families. Report 1: Before we are born. Auckland: Growing Up in New Zealand, Growing Up in New Zealand.Google Scholar
- Morton, S. M. B., Ramke, J., et al. (2014). Growing Up in New Zealand cohort alignment with all New Zealand births. Melbourne: Australian And New Zealand Journal Of Public Health.Google Scholar
- Pickett, K. E., Wakschlag, L. S., et al. (2003). Fluctuations of maternal smoking during pregnancy. Obstetrics & Gynecology, 101(1), 140–147.Google Scholar
- Salmond, C. E., Crampton, P., & Atkinson, J. (2007). NZDep2006 index of deprivation, (pp. 1–61) Wellington: Department of Public Health, University of Otago Wellington.Google Scholar
- Statistics New Zealand (2014). Infoshare: Births—VSB. Live births (Annual-Dec).Google Scholar
- U.S. Department of Health and Human Services. (2014). International comparisons of infant mortality and related factors: United States and Europe 2010. from http://www.cdc.gov/nchs/data/nvsr/nvsr63/nvsr63_05.pdf.