[Risk factors for cryptorchidism].

OBJECTIVES

To identify the main risk factors for cryptorchidism in southeast Spain, and their possible association with environmental factors.

METHODS

In this retrospective case-control study, the target population consisted of babies born in the University of Granada Hospital (UGH) in Granada, Spain, between 1 January 1992 and 31 December 1999, both inclusive. All boys from the target population aged 1 year or more diagnosed at the Pediatric Urology or Endocrinology Services of the UGH as having cryptorchidism (n = 70) were included, and a random sample of 144 baby boys born without cryptorchidism or any other related genitourinary abnormality or disease formed the control group. The mother's hospital record in the obstetrics clinic was checked to record information on potential risk factors, such as residence (specific health care district), parents' occupation, obstetric antecedents, diseases during pregnancy, gestational age at birth, birth weight and type of delivery. To search for associations between cryptorchidism and each of the variables we calculated crude and adjusted odds ratios with unconditional logistic regression analysis.

RESULTS

Low gestational age at birth (37 weeks) and cesarian section were significantly associated with cryptorchidism. We also found an association with residence of the mother in the Costa-Alpujarra health care district, but its magnitude decreased when the association was adjusted for the father's occupation in agriculture. This last factor was also associated with cryptorchidism, although the association was not statistically significant.

CONCLUSIONS

Our findings are consistent with those of other studies, except for the absence of association between low birth weight and cryptorchidism. Geographic variations in our study population suggested that environmental factors possibly related with farm work are involved in cryptorchidism.