title: Partner smoking and maternal cotinine during pregnancy: implications for negative control methods.
abstract: BACKGROUND
  Comparison of the associations of maternal and mother's partner smoking with offspring outcomes is, in theory, a useful method for assessing whether there may be an intrauterine effect of tobacco exposure on these outcomes. However, this approach assumes that the effects of passive smoking from exposure to partner smoking during pregnancy are minimal. We evaluated this assumption using a biochemical measure of tobacco exposure in pregnant women.
  
  
  METHODS
  Cotinine levels taken during the first trimester of pregnancy were measured in a sample of 3928 women from the Avon Longitudinal Study of Parents and Children. Median cotinine values were compared across categories of smoking heaviness (cigarettes per day) of the women during the first trimester and in non-smoking women by the smoking heaviness of their partner.
  
  
  RESULTS
  Cotinine levels were substantially higher in women who smoked compared to non-smokers (range of medians across smoking heaviness categories: 900-5362 ng/ml versus 20 ng/ml, interquartile range (IQR) (0-63) for non-smokers). In contrast, cotinine levels in non-smoking women were only very weakly related to partner smoking status (range of medians in women with smoking partners: 34-69 ng/ml versus 12 ng/ml, IQR (0-48) in women with non-smoking partners).
  
  
  CONCLUSIONS
  Levels of tobacco exposure from partner smoking, as assessed by cotinine, were low in non-smoking pregnant women. This suggests that using mother's partner's smoking as a negative control for investigating intrauterine effects is valid.
authors.affiliation: MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, UK Centre for Tobacco and Alcohol Studies, School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK. Electronic address: amy.taylor@bristol.ac.uk.
authors.forename: Amy E
authors.initials: AE
authors.lastname: Taylor
authors.affiliation: MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, UK.
authors.forename: George
authors.initials: G
authors.lastname: Davey Smith
authors.affiliation: School of Social Work, Virginia Commonwealth University, Richmond, VA 23284-2027, USA.
authors.forename: Cristina B
authors.initials: CB
authors.lastname: Bares
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond, VA 23298-0126, USA.
authors.forename: Alexis C
authors.initials: AC
authors.lastname: Edwards
authors.affiliation: MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, UK Centre for Tobacco and Alcohol Studies, School of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, UK.
authors.forename: Marcus R
authors.initials: MR
authors.lastname: Munafò
mesh_terms: D000328:Adult; D003367:Cotinine / Q000652:urine*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000652:urine; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects / Q000652:urine*; D018454:Spouses / Q000706:statistics & numerical data; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine
keywords: ALSPAC; Cigarette smoking; Intrauterine exposure; Negative control; Pregnancy
references.citation: Nicotine Tob Res. 2012 Feb;14(2):191-9
references.pmid: 22039071
references.citation: Tob Control. 2006 Dec;15(6):452-7
references.pmid: 17130374
references.citation: Eur J Pediatr. 1990 Jul;149(10):734-7
references.pmid: 2209668
references.citation: Am J Public Health. 1994 Sep;84(9):1407-13
references.pmid: 8092363
references.citation: J Nerv Ment Dis. 2010 Sep;198(9):672-8
references.pmid: 20823730
references.citation: Am J Epidemiol. 1995 Sep 1;142(5):525-30
references.pmid: 7677131
references.citation: J Stud Alcohol Drugs. 2011 Mar;72(2):199-209
references.pmid: 21388593
references.citation: Prev Med. 2010 Jan-Feb;50(1-2):13-8
references.pmid: 20026103
references.citation: Environ Health Perspect. 2007 Apr;115(4):623-9
references.pmid: 17450234
references.citation: Nicotine Tob Res. 2011 Oct;13(10):982-8
references.pmid: 21690317
references.citation: J Am Acad Child Adolesc Psychiatry. 2006 Apr;45(4):461-7
references.pmid: 16601651
references.citation: Hum Genet. 2008 Feb;123(1):15-33
references.pmid: 18038153
references.citation: Sci Total Environ. 2014 Feb 1;470-471:1189-96
references.pmid: 24246942
references.citation: Basic Clin Pharmacol Toxicol. 2008 Feb;102(2):245-56
references.pmid: 18226080
references.citation: Paediatr Perinat Epidemiol. 2005 Sep;19(5):377-87
references.pmid: 16115290
references.citation: Eur Addict Res. 2011;17(6):342-50
references.pmid: 22116508
references.citation: Hum Mol Genet. 2012 Dec 15;21(24):5344-58
references.pmid: 22956269
references.citation: Pediatrics. 2009 Feb;123(2):e274-81
references.pmid: 19171580
references.citation: Am J Psychiatry. 2003 Nov;160(11):1978-84
references.pmid: 14594744
references.citation: J Am Acad Child Adolesc Psychiatry. 2009 Mar;48(3):283-289
references.pmid: 19242291
references.citation: Int J Epidemiol. 2013 Feb;42(1):111-27
references.pmid: 22507743
references.citation: Pediatr Res. 2012 Jul;72(1):101-7
references.pmid: 22441375
references.citation: Hypertension. 2007 Jun;49(6):1422-8
references.pmid: 17404184
references.citation: Int J Epidemiol. 2013 Feb;42(1):97-110
references.pmid: 22507742
references.citation: Hum Mol Genet. 2009 Aug 1;18(15):2922-7
references.pmid: 19429911
references.citation: Addiction. 2014 Jun;109(6):1013-21
references.pmid: 24521169
references.citation: Nicotine Tob Res. 2005 Oct;7(5):801-8
references.pmid: 16191751
references.citation: Int J Epidemiol. 2012 Jun;41(3):722-32
references.pmid: 22407859
references.citation: Occup Environ Med. 1998 Jan;55(1):18-23
references.pmid: 9536158
references.citation: Epidemiology. 2012 Mar;23(2):350-1; author reply 351-2
references.pmid: 22317815
references.citation: Int J Epidemiol. 2009 Jun;38(3):680-9
references.pmid: 18775874
references.citation: J Epidemiol Community Health. 2010 Jan;64(1):82-8
references.pmid: 19887578
references.citation: Am J Epidemiol. 2012 Aug 1;176(3):261-8
references.pmid: 22791738
references.citation: Addict Behav. 2006 Sep;31(9):1670-82
references.pmid: 16448781
references.citation: Br Med J. 1973 Dec 8;4(5892):573-5
references.pmid: 4758516