title: The impact of cigarette smoking on zona pellucida thickness of oocytes and embryos prior to transfer into the uterine cavity.
abstract: BACKGROUND
  Smoking has been reported to promote infertility. The zona pellucida plays an important role in fertilization and implantation. We report, for the first time, the effect of cigarette smoking on zona pellucida thickness of oocytes and embryos as one of the factors that may interfere with fertility.
  
  
  METHODS
  This study comprised 169 women, grouped according to their smoking habits: 31 active smokers, whose husbands do not smoke; 44 active smokers, whose husbands smoke; 65 passive smokers, because of smoking husbands and 29 non-smokers (women and husbands). Zona pellucida thickness was measured prospectively on printed photos of 903 oocytes and 456 embryos.
  
  
  RESULTS
  The zona pellucida thickness of oocytes and embryos of non-smoking women was significantly thinner than those of active and passive smokers. However, no significant differences were observed in the natural ability of the zona pellucida to become thinner after 48 h in culture.
  
  
  CONCLUSIONS
  Our study demonstrates that active and passive cigarette smoking increases the zona pellucida thickness of oocytes and embryos. Our findings also show that active and passive smoking has no significant effect on the thinning mechanism of the zona pellucida, which implies that it is independent of the initial zona pellucida thickness.
authors.affiliation: IVF Unit, Department of Obstetrics and Gynecology, Carmel Medical Center, 7 Michal St, Haifa 34362, Israel. jshiloh@rafael.co.il
authors.forename: H
authors.initials: H
authors.lastname: Shiloh
authors.forename: S
authors.initials: S
authors.lastname: Lahav-Baratz
authors.forename: M
authors.initials: M
authors.lastname: Koifman
authors.forename: D
authors.initials: D
authors.lastname: Ishai
authors.forename: D
authors.initials: D
authors.lastname: Bidder
authors.forename: Z
authors.initials: Z
authors.lastname: Weiner-Meganzi
authors.forename: M
authors.initials: M
authors.lastname: Dirnfeld
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009865:Oocytes / Q000648:ultrastructure*; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects*; D018454:Spouses; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D015044:Zona Pellucida / Q000648:ultrastructure*
chemical_list: D014028:Tobacco Smoke Pollution