Parturition itself is the basis for fetal adrenal involution.
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.
Ben-David
Shlomit
S
Department of Neonatology, Meyer Children's Hospital, Haifa 31096, Israel.
Zuckerman-Levin
Nehama
N
Epelman
Monica
M
Shen-Orr
Zila
Z
Levin
Moshe
M
Sujov
Polo
P
Hochberg
Ze'ev
Z
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
D000735:Androstenedione; D019314:Dehydroepiandrosterone Sulfate; D006854:Hydrocortisone