Table I.

Levels of androgens in maternal serum.

Androgen	Non-pregnant	First trimester	Second trimester	Third trimester	References
fT (pmol/l)	6.2	11.1	7.5	13.3	Wilke and Utley (1987)
tT (mmol/l)	0.21–2.98	0.90–7.32	1.20–8.40	2.20–10.70	O'Leary et al. (1991)
A4 (ng/ml)	1.0–2.0	2.5–3.5	0.6–7.8	1.6–14.0	Castracane et al. (1998), Carlsen et al. (2006)
DHT (ng/ml)	0.022–0.107	0.113	0.18	0.1–0.3	Buster et al. (1979), Dawood and Saxena (1977)
SHBG (nmol/l)	42.2	68.1	279.3	246.1	Wilke and Utley (1987)
DHEA (nmol/l)	1.0–40.0	10.0–60.0	5.0–50.0	5.0–50.1	Tagawa et al. (2004)
DHEAS (nmol/l)	2000–4000	2000–4000	500–2000	500–200	Tagawa et al. (2004)

The table shows the mean concentrations of androgens as given in references quoted. tT, total testosterone; fT, free testosterone; SHBG, sex hormone binding globulin; DHEA, dehydroepiandrosterone; DHEAS, dehydroepiandrosterone sulphate; A4, androstenedione; DHT, dihydrotestosterone.