Changes in parental smoking during pregnancy and risks of adverse birth outcomes and childhood overweight in Europe and North America: An individual participant data meta-analysis of 229,000 singleton births

Elise M. Philips, Susana Santos, Leonardo Trasande, Juan J. Aurrekoetxea, Henrique Barros, Andrea von Berg, Anna Bergstroem, Philippa K. Bird, Sonia Brescianini, Carol Ni Chaoimh, Marie-Aline Charles, Leda Chatzi, Cecile Chevrier, George P. Chrousos, Nathalie Costet, Rachel Criswell, Sarah Crozier, Merete Eggesbo, Maria Pia Fantini, Sara FarchiFrancesco Forastiere, Marleen M. H. J. van Gelder, Vagelis Georgiu, Keith M. Godfrey, Davide Gori, Wojciech Hanke, Barbara Heude, Daniel Hryhorczuk, Carmen Iniguez, Hazel Inskip, Anne M. Karvonen, Louise C. Kenny, Inger Kull, Debbie A. Lawlor, Irina Lehmann, Per Magnus, Yannis Manios, Erik Melen, Monique Mommers, Camilla S. Morgen, George Moschonis, Deirdre Murray, Ellen A. Nohr, Anne-Marie Nybo Andersen, Emily Oken, Adriette J. J. M. Oostvogels, Eleni Papadopoulou, Juha Pekkanen, Costanza Pizzi, Kinga Polanska, Daniela Porta, Lorenzo Richiardi, Sheryl L. Rifas-Shiman, Nel Roeleveld, Franca Rusconi, Ana C. Santos, Thorkild I. A. Sorensen, Marie Standl, Camilla Stoltenberg, Jordi Sunyer, Elisabeth Thiering, Carel Thijs, Maties Torrent, Tanja G. M. Vrijkotte, John Wright, Oleksandr Zvinchuk, Romy Gaillard, Vincent W. V. Jaddoe*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

28 Citations (Web of Science)

Abstract

Author summaryWhy was this study done? Maternal smoking during pregnancy is an important risk factor for various birth complications and childhood overweight. It is not clear whether this increased risk is also present if mothers smoke during the first trimester only or reduce the number of cigarettes during pregnancy. The associations of paternal smoking with birth and childhood outcomes also remain unknown. What did the researchers do and find? We conducted an individual participant data meta-analysis using data from 229,158 families from 28 pregnancy and birth cohorts from Europe and North America to assess the associations of parental smoking during pregnancy, specifically of quitting or reducing smoking and maternal and paternal smoking combined, with preterm birth, small size for gestational age, and childhood overweight. We observed that smoking in the first trimester only did not increase the risk of preterm birth and small size for gestational age but was associated with a higher risk of childhood overweight, as compared to nonsmoking. Reducing the number of cigarettes during pregnancy, without quitting, was still associated with higher risks of these adverse outcomes. Paternal smoking seems to be associated, independently of maternal smoking, with the risks of childhood overweight. What do these findings mean? Population strategies should focus on parental smoking prevention before or at the start of, rather than during, pregnancy. Future studies are needed to assess the specific associations of smoking in the preconception and childhood periods with offspring outcomes.

Background Fetal smoke exposure is a common and key avoidable risk factor for birth complications and seems to influence later risk of overweight. It is unclear whether this increased risk is also present if mothers smoke during the first trimester only or reduce the number of cigarettes during pregnancy, or when only fathers smoke. We aimed to assess the associations of parental smoking during pregnancy, specifically of quitting or reducing smoking and maternal and paternal smoking combined, with preterm birth, small size for gestational age, and childhood overweight. Methods and findings We performed an individual participant data meta-analysis among 229,158 families from 28 pregnancy/birth cohorts from Europe and North America. All 28 cohorts had information on maternal smoking, and 16 also had information on paternal smoking. In total, 22 cohorts were population-based, with birth years ranging from 1991 to 2015. The mothers' median age was 30.0 years, and most mothers were medium or highly educated. We used multilevel binary logistic regression models adjusted for maternal and paternal sociodemographic and lifestyle-related characteristics. Compared with nonsmoking mothers, maternal first trimester smoking only was not associated with adverse birth outcomes but was associated with a higher risk of childhood overweight (odds ratio [OR] 1.17 [95% CI 1.02-1.35],Pvalue = 0.030). Children from mothers who continued smoking during pregnancy had higher risks of preterm birth (OR 1.08 [95% CI 1.02-1.15],Pvalue = 0.012), small size for gestational age (OR 2.15 [95% CI 2.07-2.23],Pvalue <0.001), and childhood overweight (OR 1.42 [95% CI 1.35-1.48],Pvalue <0.001). Mothers who reduced the number of cigarettes between the first and third trimester, without quitting, still had a higher risk of small size for gestational age. However, the corresponding risk estimates were smaller than for women who continued the same amount of cigarettes throughout pregnancy (OR 1.89 [95% CI 1.52-2.34] instead of OR 2.20 [95% CI 2.02-2.42] when reducing from 5-9 to = 10 to 5-9 and

Original languageEnglish
Article number1003182
Number of pages25
JournalPLOS Medicine
Volume17
Issue number8
DOIs
Publication statusPublished - Aug 2020

Keywords

  • MATERNAL SMOKING
  • PRETERM BIRTH
  • DNA METHYLATION
  • ASSOCIATION
  • WEIGHT
  • GROWTH
  • EXPOSURE
  • CHILDREN
  • CESSATION
  • OBESITY

Cite this