Successful paediatric renography does not require sedation.

Introduction: Sedation is often used to optimise ren-ography in children < 3 years, but it requires continuous monitoring.

Methods: We discontinued routine use of chloral hydrate sedation of patients undergoing renography, and introduced that children < 2 years were placed in a child immobiliser for nuclear examinations at the Department of Paediatrics before being transported for renography. In addition, children < 3 years were offered melatonin, which is not a sedative.

Acquired cryptorchidism is frequent in infancy and childhood.

Accurate prevalence data for acquired cryptorchidism are currently sparse and systematic prospective studies have not yet been reported. Our aim was to determine the prevalence of testicular ascent in childhood. In a prospective longitudinal population-based child cohort from Copenhagen, Denmark (1997-2007), testicular position was examined according to a standardised protocol in a total of 1072 boys, at birth (n = 1051), at 3 months (n = 983), 18 months (n = 888), 36 months (n = 790) and again once between 4 1/2 and 10 years of age (n = 509).

Serum insulin-like growth factor-I (IGF-I) and growth in children born after assisted reproduction.

Context: Concern has been raised about the safety of assisted reproduction techniques for the offspring.

Objectives: The objective of the study was to investigate postnatal growth and growth factors in children born after intra-cytoplasmatic sperm injection (ICSI) and in vitro fertilization (IVF).

Design: The study had two cohorts: a population-based longitudinal infant cohort 0-36 months [236 ICSI, 173 IVF, 1530 naturally conceived (NC)], and a cross-sectional child cohort at 5 yr (68 ICSI, 67 IVF, 70 NC).

Larger testes and higher inhibin B levels in Finnish than in Danish newborn boys.

Context: Recent studies showed that male reproductive health problems, such as cryptorchidism, hypospadias, testicular cancer, and low sperm quality, are more prevalent in Denmark than in Finland.

Objectives: We hypothesized that, if fetal testicular dysgenesis contributed to these observations, differences in gonadal development and the hypothalamus-pituitary-testis axis would already be detectable perinatally. Thus, we investigated healthy newborn boys in both countries.

Hormonal changes in 3-month-old cryptorchid boys.

Context: Hormonal dysregulation has been suggested to be one of many etiological factors of cryptorchidism.

Objectives: The objective of this study was to assess the hypothalamic-pituitary-testicular axis in cryptorchid boys during the postnatal hormonal surge.

Design: This was a prospective, longitudinal, population-based study.

Postnatal penile length and growth rate correlate to serum testosterone levels: a longitudinal study of 1962 normal boys.

Objective: Infant boys show a brief activation of their hypothalamic-pituitary-gonadal axis shortly after birth, the physiological significance of which is poorly understood. The objective of the study was to investigate the correlation between endogenous testosterone levels and penile size and growth.

Design: Prospective, longitudinal population-based study taking place at two large primary obstetric centres at the University Hospitals of Copenhagen, Denmark, and Turku, Finland.