Risk factors for different phenotypes of hypospadias: results from a Dutch case-control study.

Unlabelled: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The various phenotypes of hypospadias may result from disturbances of dissimilar embryonic processes in different time windows, suggesting aetiological heterogeneity; however, only a few studies have investigated the risk factors for the different hypospadias phenotypes. The study confirmed that genetic predisposition possibly plays a role in anterior and middle hypospadias, as shown by the large effect estimates for familial occurrence of these forms of hypospadias. By contrast, the posterior phenotype was more often associated with pregnancy-related factors, such as primiparity, preterm delivery, and being small for gestational age.

Exploration of gene-environment interactions, maternal effects and parent of origin effects in the etiology of hypospadias.

Purpose: Hypospadias is a common congenital malformation of the male external genitalia. Association studies for single nucleotide polymorphisms in genes encoding steroid 5alpha-reductase, estrogen receptors 1 and 2, and activating transcription factor 3 have been equivocal. We examined whether nonreplication of findings for 4 single nucleotide polymorphisms in these genes could be due to interaction with environmental exposures.

Occupational exposure to endocrine disruptors and time to pregnancy among couples in a large birth cohort study: the Generation R Study.

Objective: To study the influence of occupational exposure to endocrine disruptors (EDs) on time to pregnancy (TTP).

Design: Cross-sectional analysis within a prospective, population-based cohort study.

Setting: Medical center.

Estrogenic and androgenic activities in total plasma measured with reporter-gene bioassays: relevant exposure measures for endocrine disruptors in epidemiologic studies?

Measurements of estrogenic and androgenic activities in total plasma with Chemically Activated LUciferase gene eXpression (CALUX®) bioassays could provide biologically relevant measures for exposure to endocrine disruptors in epidemiologic studies. The objective of this study was to explore the effects of a variety of sources of potential endocrine disruptors on estrogenic and androgenic activities in total plasma measured by CALUX®. Plasma samples and interview data on sources of potential endocrine disruptors were collected from 108 men with different exposures profiles.

Risk factors for undescended testis.

Objective: To contribute to the understanding of the etiology of undescended testis (UDT), by exploring a wide range of potential risk factors in a case-referent study.

Patients And Methods: Cases and referents were recruited at five hospitals and included 200 boys with surgically corrected UDT and 629 boys with persistent middle ear effusion. Risk factor data were obtained by postal questionnaires to both parents.

Maternal and paternal risk factors for anorectal malformations: a Dutch case-control study.

Background: Anorectal malformations (ARM) are major congenital malformations that usually require a multitude of surgical procedures at a very early age and have a large impact on the lives of patients and their parents. The causes of ARM are still largely unknown, but they are assumed to have a multifactorial etiology. A few studies focused on environmental risk factors, but evidence is still scarce.

Hypospadias: risk factor patterns and different phenotypes.

Objective: To obtain more insight into the origin of hypospadias by exploring a wide range of potential risk factors in a case-referent study in which a distinction was made between different phenotypes.

Patients And Methods: Cases and referents were 305 boys with hypospadias and 629 boys with middle ear effusion whose parents completed postal questionnaires. Hypospadias phenotype was classified as distal (195 boys), middle (67), and proximal (43).

Risk factors for hypospadias.

Despite being one of the most common congenital defects in boys, the etiology of hypospadias remains largely unknown. In this case-referent study, we evaluated a wide spectrum of potential risk factors for hypospadias. Cases were identified from the hospital information system, and referents were recruited through the parents of the cases.