title: Postnatal developmental changes in the pituitary-ovarian axis in preterm and term infant girls.
abstract: BACKGROUND
  Postnatal pituitary-testicular activation in infant boys is well characterized. However, the ovarian response to pituitary activation in infancy is less well understood.
  
  
  OBJECTIVE
  The aim of the study was to compare postnatal developmental changes in the pituitary-ovarian axis in preterm and term infant girls.
  
  
  METHODS
  Sixty-three infant girls, divided into three groups according to gestational age (GA) [i.e. full term (FT; n = 29; GA, 37-42 wk), near term (NT; n = 17; GA, 34-37 wk), and preterm (PT; n = 17; GA, 24-34 wk)] were examined monthly from 1 wk (D7) to 6 months (M1-M6) of age and reexamined at the corrected age of 14 months (cM14).
  
  
  METHODS
  We performed a longitudinal follow-up of urinary FSH and serum anti-Müllerian hormone (AMH) levels and the number of follicles in transabdominal ovarian ultrasonography.
  
  
  RESULTS
  The postnatal FSH surge was stronger and more prolonged in NT and PT girls than in FT girls (P ≤ 0.001). Increased folliculogenesis and a rise in AMH levels were observed in all three groups after the FSH surge. In NT and PT girls, follicular development was delayed in comparison with FT girls, and a decrease in high FSH levels around the 40th postmenstrual week was temporally associated with the appearance of antral follicles in ultrasonography and an increase in AMH levels.
  
  
  CONCLUSIONS
  The postnatal FSH surge results in transient ovarian stimulation in term and preterm girls. A delay in ovarian folliculogenesis shown in ovarian ultrasonography and by low serum AMH levels may provide an explanation for the exaggerated FSH surge in NT and PT girls.
authors: Department of Pediatrics, University of Eastern Finland and Kuopio University Hospital, FI-70211 Kuopio, Finland.
authors: Tanja
authors: T
authors: Kuiri-Hänninen
authors: Sanna
authors: S
authors: Kallio
authors: Raija
authors: R
authors: Seuri
authors: Erja
authors: E
authors: Tyrväinen
authors: Annikki
authors: A
authors: Liakka
authors: Juha
authors: J
authors: Tapanainen
authors: Ulla
authors: U
authors: Sankilampi
authors: Leo
authors: L
authors: Dunkel
mesh_terms: D054304:Anti-Mullerian Hormone / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000652:urine; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008137:Longitudinal Studies; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000254:growth & development*; D010053:Ovary / Q000000981:diagnostic imaging / Q000254:growth & development*; D010902:Pituitary Gland / Q000254:growth & development*; D014463:Ultrasonography
chemical_list: D054304:Anti-Mullerian Hormone; D005640:Follicle Stimulating Hormone