title: Cryptorchidism according to maternal gestational smoking.
abstract: BACKGROUND
  It has been suggested that maternal smoking during pregnancy is a risk factor for low sperm counts and testicular cancer in the offspring. Cryptorchidism is associated with both of these disorders and might share causal mechanisms.
  
  
  METHODS
  We used prospective information on prenatal exposures and obstetric information on the birth of 5716 boys, collected from 1984 to 1987. During the 16-19 years of follow-up, 270 cases of cryptorchidism were diagnosed, and 185 of these boys underwent orchiopexy.
  
  
  RESULTS
  Compared with nonsmokers, the adjusted risk ratio for being diagnosed with cryptorchidism was 1.1 (95% confidence interval = 0.8-1.6) if the mothers smoked 10-19 cigarettes/day and 2.3 (1.1-5.0) if they smoked > or = 20 cigarettes/day. The risk ratios for orchiopexy were 1.4 (0.9-2.1) and 1.8 (0.6-5.0), respectively.
  
  
  CONCLUSIONS
  An excess risk of cryptorchidism was observed among sons of mothers who smoked 10 cigarettes or more per day during pregnancy. In recognition of the limited power of this study, the findings should be replicated in larger cohorts.
authors.affiliation: Department of Occupational Medicine, Aarhus University Hospital, Aarhus, Denmark. morten@sondergaard-jensen.dk
authors.forename: Morten Søndergaard
authors.initials: MS
authors.lastname: Jensen
authors.forename: Gunnar
authors.initials: G
authors.lastname: Toft
authors.forename: Ane Marie
authors.initials: AM
authors.lastname: Thulstrup
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Bonde
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003456:Cryptorchidism / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D018811:Maternal Exposure; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012907:Smoking / Q000009:adverse effects*