title: Effect of sexual abstinence on the proportion of X-bearing sperm as assessed by multicolor fluorescent in situ hybridization.
abstract: OBJECTIVE
  To document the relation between sexual abstinence and the proportion of X-bearing sperm in the ejaculate.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Medical college.
  
  
  METHODS
  Ten normospermic men, aged 30 to 40 years, provided two semen samples: the first sample was obtained 1.0 to 1.5 days after ejaculation; the second, 7 to 10 days after ejaculation.
  
  
  METHODS
  Abstinence.
  
  
  METHODS
  Proportion of X- and Y-bearing sperm in two ejaculates.
  
  
  RESULTS
  Multicolor fluorescent in situ hybridization using directly labeled alpha-satellite probes specific for chromosomes 18, X and Y were used to analyze 40,273 sperm. After 1.0 to 1.5 days of abstinence, there were 47.6% +/- 1.7% (mean +/- SD) X-bearing sperm, and after 7 to 10 days of abstinence, there were 49.6% +/- 2.1% X-bearing sperm. The X:Y ratio increased marginally from 0.905 to 0.981.
  
  
  CONCLUSIONS
  Sexual abstinence marginally increases the proportion of X-bearing sperm in the ejaculate as assessed by multicolor fluorescent in situ hybridization. This change of borderline statistical significance probably has little impact on the secondary sex ratio.
authors.affiliation: Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Hilsenrath
authors.forename: M
authors.initials: M
authors.lastname: Swarup
authors.forename: F Z
authors.initials: FZ
authors.lastname: Bischoff
authors.forename: J E
authors.initials: JE
authors.lastname: Buster
authors.forename: S A
authors.initials: SA
authors.lastname: Carson
mesh_terms: D000328:Adult; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D012725:Sexual Behavior; D013094:Spermatozoa / Q000648:ultrastructure*; D014960:X Chromosome; D014998:Y Chromosome