Minipuberty in Male Full-term Neonates Appropriate and Small for Gestational Age and in Preterm Babies: Data from a Single Centre

INTRODUCTION: The postnatal activation of the hypothalamic-pituitary-gonadal (HPG) axis is usually known as 'minipuberty'. There are still open questions about its biological function and significance depending on sex, gestational age (GA) and birth weight (BW) with few available longitudinal data. METHODS: A single-centre, longitudinal study to quantify urinary follicle stimulating hormone (uFSH), luteinizing hormone (uLH) and testosterone (uTs) in male neonates. Neonates were enrolled and stratified into three subgroups: full-term boys appropriate for GA (FT AGA); FT boys with BW ≤3rd centile [FT small for gestational age (SGA)]; and preterm (PT) boys ≤33 weeks of GA. Urinary hormones were correlated to simultaneous auxological parameters, linear growth and external genitalia at scheduled time-points. RESULTS: Forty-six boys were recruited, with subgroup sizes FT AGA n=23, FT SGA n=11 and PT n=12. PT boys display a pulsatile pattern of urinary gonadotropins (uGns) with higher levels of uLH and a gradual increase of uTs. Testicular descent started from 29-32 weeks with the peak of uTs. During the first 12-months post-term age (PTA), FT AGA boys displayed a better linear growth (p