RESUMEN
CONTEXT: Cryptorchidism is the most common malformation in newborn boys. Maternal diabetes has previously been suggested to be a risk factor for this disorder in one epidemiological study. OBJECTIVE: Evaluation of the prevalence of maternal glucose metabolism disorders during pregnancy in newborn boys having normal testicular descent or congenital cryptorchidism. DESIGN: Postnatal analysis of maternal history concerning glucose metabolism abnormalities during pregnancy among cryptorchid and healthy Finnish boys. SETTING AND PARTICIPANTS: The material of this case-control study comprises 1163 boys with normal testicular descent at birth and 125 boys with congenital cryptorchidism. All these singleton Finnish boys were born in Turku University Central Hospital (1997-2001) and were examined at birth and/or at the expected date of delivery. MAIN OUTCOME MEASURES: Information about maternal diabetes diagnosis and abnormality of the result of a 2-h 75-g oral glucose tolerance test during pregnancy were obtained from the hospital records after delivery. RESULTS: After adjustment for possible confounding factors, i.e. maternal smoking during pregnancy, maternal age at delivery, and risk factors of cryptorchidism, e.g. prematurity and weight for gestational age, abnormal maternal glucose metabolism was significantly more common in the group of cryptorchid boys [diet-treated gestational diabetes, P = 0.0001; odds ratio, 3.98 (95% confidence interval, 1.97-8.05); diet-treated gestational diabetes or only an abnormal result in oral glucose tolerance test, P = 0.0016; odds ratio, 2.44 (95% confidence interval, 1.40-4.25)] when compared with boys with normal testicular descent. CONCLUSIONS: Mildly abnormal glucose metabolism during pregnancy was associated with an increased risk for congenital cryptorchidism. The mechanism remains to be elucidated.
Asunto(s)
Criptorquidismo/epidemiología , Criptorquidismo/etiología , Diabetes Gestacional/epidemiología , Adulto , Glucemia/análisis , Estudios de Casos y Controles , Femenino , Prueba de Tolerancia a la Glucosa/estadística & datos numéricos , Humanos , Recién Nacido , Masculino , Embarazo , Factores de RiesgoRESUMEN
UNLABELLED: Phthalates adversely affect the male reproductive system in animals. We investigated whether phthalate monoester contamination of human breast milk had any influence on the postnatal surge of reproductive hormones in newborn boys as a sign of testicular dysgenesis. DESIGN: We obtained biologic samples from a prospective Danish-Finnish cohort study on cryptorchidism from 1997 to 2001. We analyzed individual breast milk samples collected as additive aliquots 1-3 months postnatally (n = 130; 62 cryptorchid/68 healthy boys) for phthalate monoesters [mono-methyl phthalate (mMP), mono-ethyl phthalate (mEP), mono-n-butyl phthalate (mBP), mono-benzyl phthalate (mBzP), mono-2-ethylhexyl phthalate (mEHP), mono-isononyl phthalate (miNP)]. We analyzed serum samples (obtained in 74% of all boys) for gonadotropins, sex-hormone binding globulin (SHBG), testosterone, and inhibin B. RESULTS: All phthalate monoesters were found in breast milk with large variations [medians (minimum-maximum)]: mMP 0.10 (< 0.01-5.53 microg/L), mEP 0.95 (0.07-41.4 microg/L), mBP 9.6 (0.6-10,900 microg/L), mBzP 1.2 (0.2-26 microg/L), mEHP 11 (1.5-1,410 microg/L), miNP 95 (27-469 microg/L). Finnish breast milk had higher concentrations of mBP, mBzP, mEHP, and Danish breast milk had higher values for miNP (p = 0.0001-0.056). No association was found between phthalate monoester levels and cryptorchidism. However, mEP and mBP showed positive correlations with SHBG (r = 0.323, p = 0.002 and r = 0.272, p = 0.01, respectively); mMP, mEP, and mBP with LH:free testosterone ratio (r = 0.21-0.323, p = 0.002-0.044) and miNP with luteinizing hormone (r = 0.243, p = 0.019). mBP was negatively correlated with free testosterone (r = -0.22, p = 0.033). Other phthalate monoesters showed similar but nonsignificant tendencies. CONCLUSIONS: Our data on reproductive hormone profiles and phthalate exposures in newborn boys are in accordance with rodent data and suggest that human Leydig cell development and function may also be vulnerable to perinatal exposure to some phthalates. Our findings are also in line with other recent human data showing incomplete virilization in infant boys exposed to phthalates prenatally.