PRENATAL RISK-FACTORS FOR CRYPTORCHIDISM - A RECORD LINKAGE STUDY

Using data from the Oxford Record Linkage Study (ORLS), we conducted a case-control study to examine prenatal risk factors for cryptorchidis m. We identified 1449 boys born during 1970-86 for whom there was a re cord of an orchidopexy during 1970-87. Up to eight controls were match ed to each case on year of birth and hospital or place of delivery. Fo r each boy and his mother we extracted abstracts of maternity and gene ral hospital records from the ORLS. Low birthweight (trend P < 0.001), low social class (trend P < 0.001), breech presentation (relative ris k 1.67; 95% confidence interval [CI] 1.16, 2.41), pre-eclampsia (1.17 [1.00, 1.37]), artificial feeding (1.22 [1.04, 1.45]) and episiotomy ( 1.13 [1.00, 1.27]) were identified as independent risk factors for cry ptorchidism. Gestational age was not independently associated with cry ptorchidism after adjusting for birthweight (P=0.33), and this observa tion suggested that some cryptorchid boys may have suffered from intra uterine growth retardation. Low birthweight, breech presentation and p re-eclampsia may have in common poor placental function and impaired f etal growth, which may be causes of cryptorchidism.