title: Tobacco use in the third trimester of pregnancy and its relationship to birth weight. A prospective study in Spain.
abstract: BACKGROUND
  Few studies have been carried out in Spain examining the use of tobacco amongst expectant mothers and its effect on birth weight.
  
  
  OBJECTIVE
  To observe the proportion of expectant mothers who smoke during their pregnancy, and the impact of tobacco consumption on maternal and birth weight. We also aimed to identify the trimester of pregnancy in which tobacco use produced the greatest reduction in birth weight.
  
  
  METHODS
  Prospective observational study in Spain. A random sampling strategy was used to select health centres and participant women. A total of 137 individuals were enrolled in the study. Exposure to tobacco was measured through a self-reported questionnaire. Regressions were performed to obtain a predictive model for birth weight related to smoking.
  
  
  RESULTS
  Overall, 35% of study participants were smokers during the pre-gestational period (27% in the first trimester, 21.9% in the second and 21.2% in the third). 38.7% of smoking cessation attempts took place in the third-trimester. Pregnant women who smoked up to the third trimester had a higher risk of giving birth to a baby under 3000g, compared to non-smokers (OR=5.94, CI 95%: 1.94-18.16). Each additional unit of tobacco consumed daily in the 3rd trimester led to a 32g reduction in birth weight.
  
  
  CONCLUSIONS
  An important proportion of pregnant women in Spain smoke during pregnancy. Pregnant women exposed to tobacco have newborns with lower birth weight. Smoking during the 3rd trimester of pregnancy is associated with the greatest risk of lower birth weight.
authors.affiliation: Department of Obstetrics and Gynecology, Hospital Universitario de la Ribera, Crta. Corbera km 1, 46.600 Valencia, Spain; Department of Nursing, Universidad Católica de Valencia, C/ Jesús, 10, 46.007 Valencia, Spain(b). Electronic address: rvila@hospital-ribera.com.
authors.forename: Rafael
authors.initials: R
authors.lastname: Vila Candel
authors.affiliation: Department of Nursing, Universidad Católica de Valencia, C/ Jesús, 10, 46.007 Valencia, Spain(b); Department of Obstetrics and Gynecology, Hospital Luis Alcanyis, Avda. Ausias March, 46.800 Xativa, Spain(c). Electronic address: soriano_fravid@gva.es.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Soriano-Vidal
authors.affiliation: Department of Nursing, Universidad Católica de Valencia, C/ Jesús, 10, 46.007 Valencia, Spain(b); Department of Public Health, Conselleria de Sanitat de Valencia, C/ Micer Mascó, 31, 46010 Valencia, Spain(d). Electronic address: hevilla_enr@gva.es.
authors.forename: Enrique
authors.initials: E
authors.lastname: Hevilla Cucarella
authors.affiliation: National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Healthcare Associated Infection and Antimicrobial Resistance at Imperial College London, Du Cane Road, London W12 0NN, United Kingdom(e). Electronic address: e.castro-sanchez@imperial.ac.uk.
authors.forename: Enrique
authors.initials: E
authors.lastname: Castro-Sánchez
authors.affiliation: Department of Preventive Medicine and Public Health, Universitat de Valencia, Avda. Blasco Ibañez, 15, 46.010 Valencia, Spain(f). Electronic address: jose.maria.martin@uv.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Martin-Moreno
mesh_terms: D000328:Adult; D001724:Birth Weight; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D011247:Pregnancy; D011248:Pregnancy Complications; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D011897:Random Allocation; D012907:Smoking / Q000009:adverse effects*; D013030:Spain; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution
keywords: BMI; Birth weight; Cessation; Pregnancy; Tobacco