Perinatal correlates of specific histological types of testicular cancer in patients below 35 years of age: a case-cohort study based on midwives' records in Denmark.

Our aim was to estimate the risk of specific histological types of testicular cancer associated with perinatal factors. We conducted a case-control study with 357 cases and 704 controls born between 1950 and 1968. Cases were identified through a patient registry of all patients treated in Denmark. Data on parents' age, mothers' parity, birth weight, gestational age and undescended testes were extracted from midwives' records written shortly after delivery. The risk of testicular cancer was highest for those who has the oldest mothers (30-45 years) and for those who had the lowest parity (primipara). For newborns with 2 or more signs of prematurity (born before 8 months of gestation, birth weight below 2,500 g, birth length 40-49 cm, soft nails and undescended testis) the OR was 1.62. The association between undescended testis at birth and testicular cancer was not present for boys born after 1955. The high risk of testicular cancer among primipara was mainly seen for seminomas. All cancer types were associated with mother's age, but only the OR for teratomas was statistically significant.