hrp0097fc7.1 | Sex differentiation, gonads and gynaecology or sex endocrinology | ESPE2023

Polygenic scores for testosterone and SHBG are associated with hormone levels in male infants

Siegfried Busch Alexander , Lindhardt Ljubicic Marie , N. Upners Emmie , B. Fischer Margit , P Hagen Casper , Juul Anders

Background: The male Hypothalamic-Pituitary-Gonadal (HPG) axis undergoes a transient activity phase during the first months of life with surging serum concentrations of reproductive hormones. Theoretically, the hormonal surge could represent a passive postnatal feedback to the withdrawal from the high sex steroid levels in pregnancy. However, we believe that minipuberty rather represents an active, tightly genetically-regulated biological process. We therefore...

hrp0097rfc7.1 | Sex differentiation, gonads and gynaecology or sex endocrinology | ESPE2023

Penile width increases more clearly than penile length during minipuberty: a longitudinal study of 136 healthy infant boys

Mola Gylli , Siegfried Busch Alexander , Lindhardt Ljubicic Marie , N. Upners Emmie , Bistrup Fischer Margit , Juul Anders , P. Hagen Casper

Background: In minipuberty, the male hypothalamic-pituitary-gonadal (HPG) axis is transiently activated triggering a surge in reproductive hormones causing growth of the genitalia. Longitudinal individual growth of the infant penis during minipuberty and associations to the HPG axis and IGF-I have not been thoroughly assessed.Aim: To describe the development of penile length and width as well as their relation to serum c...

hrp0097rfc7.4 | Sex differentiation, gonads and gynaecology or sex endocrinology | ESPE2023

Serum steroid metabolome dynamics during infancy: a prospective, longitudinal cohort of healthy boys

Siegfried Busch Alexander , Lindhardt Ljubicic Mariee , N. Upners Emmie , B. Fischer Margit , P. Hagen Casper , Frederiksen Hanne , Juul Anders

Background: The circulating steroid metabolome in boys undergoes significant changes during infancy reflecting functional and structural rearrangements of the adrenal glands as well as the transient activity of the hypothalamic–pituitary–gonadal axis, also called minipuberty. Studies investigating the serum steroid metabolome dynamics during infancy in a longitudinal manner are however sparse.Objective: We ai...

hrp0097p1-204 | Adrenals and HPA Axis | ESPE2023

Longitudinal Changes in Serum DLK1 Concentrations During Minipuberty in Healthy Infant Girls; Association to Changes in Linear Growth and Fat Mass

Vilmann Lea , Siegfried Busch Alexander , Lindhardt Ljubicic Marie , N. Upners Emmie , Bistrup Fischer Margit , P. Hagen Casper , Juul Anders

Background: Growth in infancy is considered primarily to be regulated by nutrition and insulin, whereas less is known about the influence of IGF-I, reproductive hormones and other factors of importance. Recently, paternally inherited genetic defects of DLK1 (Delta-like 1 homolog) were found in girls with central precocious puberty (CPP) with a metabolic phenotype. In addition, low maternal serum DLK1 concentrations were significantly lower in pregnant women wh...

hrp0095rfc6.2 | Sex Development and Gonads | ESPE2022

Dynamic changes of reproductive hormones in male minipuberty: Temporal dissociation of Leydig- and Sertoli-cell activity

S. Busch Alexander , Lindhardt Ljubicic Marie , N Upners Emmie , Bistrup Fischer Margit , Lau Raket Lars , Frederiksen Hanne , Albrethsen Jakob , Holm Johannsen Trine , P Hagen Casper , Juul Anders

Background: The male Hypothalamic-Pituitary-Gonadal (HPG) axis is transiently active during the first months of life with surging serum concentrations of reproductive hormones. This period, termed minipuberty, promotes masculinization, including testicular, and penile growth, as well as further testicular descent in males. It appears to be essential for priming specific cell types, i.e. Sertoli-, Leydig-, and germ cells, including subsequent growth and maturat...