The role of androgens in fetal growth: observational study in two genetic models of disordered androgen signalling.
OBJECTIVE
To examine the role of androgens on birth weight in genetic models of altered androgen signalling.


METHODS
Cambridge Disorders of Sex Development (DSD) database and the Swedish national screening programme for congenital adrenal hyperplasia (CAH).


METHODS
(1) 29 girls with XY karyotype and mutation positive complete androgen insensitivity syndrome (CAIS); (2) 43 girls and 30 boys with genotype confirmed CAH.


METHODS
Birth weight, birth weight-for-gestational-age (birth weight standard deviation score (SDS)) calculated by comparison with national references.


RESULTS
Mean birth weight SDS in CAIS XY infants was higher than the reference for girls (mean, 95% CI: 0.4, 0.1 to 0.7; p=0.02) and was similar to the national reference for boys (0.1, -0.2 to 0.4). Birth weight SDS in CAH girls was similar to the national reference for girls (0.0, -0.2 to 0.2) and did not vary by severity of gene mutation. Birth weight SDS in CAH boys was also similar to the national reference for boys (0.2, -0.2 to 0.6).


CONCLUSIONS
CAIS XY infants have a birth weight distribution similar to normal male infants and birth weight is not increased in infants with CAH. Alterations in androgen signalling have little impact on birth weight. Sex dimorphism in birth size is unrelated to prenatal androgen exposure.
Miles
Harriet L
HL
Department of Paediatrics, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
Gidlöf
Sebastian
S
Nordenström
Anna
A
Ong
Ken K
KK
Hughes
Ieuan A
IA
D000312:Adrenal Hyperplasia, Congenital / Q000235:genetics / Q000503:physiopathology*; D013734:Androgen-Insensitivity Syndrome / Q000235:genetics / Q000503:physiopathology*; D000728:Androgens / Q000502:physiology*; D001724:Birth Weight / Q000502:physiology; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D005865:Gestational Age; D006061:Gonadal Dysgenesis, 46,XY / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008957:Models, Genetic; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012727:Sex Characteristics; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
D000728:Androgens