title: Parturition itself is the basis for fetal adrenal involution.
abstract: BACKGROUND
  Newborn infants show a postnatal decline in androgen levels as the fetal adrenal glands involute.
  
  
  OBJECTIVE
  Placental factors up-regulate dehydroepiandrosterone sulfate (DHEA-S) generation. Hence, regardless of age, parturition will result in fetal adrenal involution and decline in DHEA-S levels.
  
  
  METHODS
  Premature neonates (n = 30) with gestational age 26-35 wk were studied. Adrenal volume by ultrasonography and serum DHEA-S, cortisol, and androstendione levels were followed weekly between d 1 and 28 of life.
  
  
  RESULTS
  Serum DHEA-S was high on d 1 of life, declining rapidly regardless of gestational age during the first week of life (P < 0.001), and serum androstenedione and cortisol levels followed a similar pattern. Androstenedione levels showed a rise as of d 21 of life in boys but not in girls. The adrenals decreased in ultrasonographic volume from d 1 to 14 of life (P < 0.001), regardless of gestational age.
  
  
  CONCLUSIONS
  Involution of the adrenal is faster than previously reported and, regardless of gestational age, occurs within the first week of life in terms of hormone secretion and within 2 wk in adrenal size. Involution involves a decline in DHEA-S but also in androstenedione and cortisol secretion, with a change in enzymatic activity. Males and females differ in their androstenedione levels and enzymatic activity. Parturition itself is the basis for fetal adrenal involution, supporting a key role for placental factors in maintaining the fetal adrenal and generating adrenal androgens.
authors.affiliation: Department of Neonatology, Meyer Children's Hospital, Haifa 31096, Israel.
authors.forename: Shlomit
authors.initials: S
authors.lastname: Ben-David
authors.forename: Nehama
authors.initials: N
authors.lastname: Zuckerman-Levin
authors.forename: Monica
authors.initials: M
authors.lastname: Epelman
authors.forename: Zila
authors.initials: Z
authors.lastname: Shen-Orr
authors.forename: Moshe
authors.initials: M
authors.lastname: Levin
authors.forename: Polo
authors.initials: P
authors.lastname: Sujov
authors.forename: Ze'ev
authors.initials: Z
authors.lastname: Hochberg
mesh_terms: D000311:Adrenal Glands / Q000000981:diagnostic imaging / Q000196:embryology* / Q000254:growth & development; D000735:Androstenedione / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D005260:Female; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007231:Infant, Newborn; D008297:Male; D036801:Parturition / Q000502:physiology*; D011247:Pregnancy; D014463:Ultrasonography
chemical_list: D000735:Androstenedione; D019314:Dehydroepiandrosterone Sulfate; D006854:Hydrocortisone