title: Placental Weight and Male Genital Anomalies: A Nationwide Danish Cohort Study.
abstract: The most consistently reported risk indicators for the male genital anomalies cryptorchidism and hypospadias are prematurity and low birth weight. Placental dysfunction has been hypothesized as a possible underlying cause, and an association between placental weight at birth and hypospadias has been indicated. In a population-based cohort of 388,422 Danish singleton boys born alive (1997-2008), we studied the association between placental weight and cryptorchidism and hypospadias. Missing data were handled with multiple imputation, and we estimated hazard ratios by means of Cox regression models. During follow-up, 1,713 boys were diagnosed with hypospadias and 6,878 with cryptorchidism (3,624 underwent corrective surgery). We observed an association between low placental weight and risk of both genital anomalies. Boys with a placental weight in the lowest decile (<10%) had higher risks of both cryptorchidism (hazard ratio = 1.52, 95% confidence interval: 1.31, 1.76) and hypospadias (hazard ratio = 1.97, 95% confidence interval: 1.59, 2.45) than boys in the reference decile (50.0-59.9%). In conclusion, we found higher risks of both genital malformations in boys born with a low placental weight. The relationship seemed stronger for hypospadias than for cryptorchidism. Taken together, our data support a role for placental dysfunction in the etiology of these anomalies.
authors.forename: Linn Håkonsen
authors.initials: LH
authors.lastname: Arendt
authors.forename: Cecilia Høst
authors.initials: CH
authors.lastname: Ramlau-Hansen
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Wilcox
authors.forename: Tine Brink
authors.initials: TB
authors.lastname: Henriksen
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.forename: Morten Søndergaard
authors.initials: MS
authors.lastname: Lindhard
mesh_terms: D015331:Cohort Studies; D003456:Cryptorchidism / Q000453:epidemiology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007021:Hypospadias / Q000453:epidemiology*; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D010920:Placenta / Q000033:anatomy & histology*; D011247:Pregnancy; D012307:Risk Factors
keywords: congenital abnormalities; cryptorchidism; hypospadias; placenta; pregnancy; risk factors