LONGITUDINAL-STUDY OF MATERNAL PLASMA BIOAVAILABLE TESTOSTERONE AND ANDROSTANEDIOL GLUCURONIDE LEVELS DURING PREGNANCY

OBJECTIVE The aim of this study to evaluate during normal pregnancy pl asma bioavailable testosterone and androstanediol glucuronide levels. MEASUREMENTS Bioavailable testosterone, androstanediol glucuronide and SHBG levels were evaluated every 4 weeks from week 6 to week 38 in 10 normal pregnant women. We also measured plasma oestradiol, oestriol, Delta(4)-androstenedione, 17-hydroxyprogesterone, progesterone and tes tosterone. RESULTS The mean bioavailable testosterone levers were with in the range of non-pregnant women but with an increasing trend until delivery. Androstanediol glucuronide had increased at weeks 6 and 8, d ecreased at week 14, remained low at week 30, and increased again at w eek 34. SHBG was significantly correlated with testosterone, oestradio l and oestriol. No correlation could be established between androstane diol glucuronide and any other parameter. DISCUSSION Bioavailable test osterone (non-SHBG bound testosterone) represents the sum of free test osterone plus albumin bound testosterone. The increase in testosterone concentrations with decreased albumin levels during pregnancy, could suggest reduced metabolic clearance of testosterone throughout pregnan cy. No correlation was established between the decrease in androstaned iol glucuronide and increase in progesterone, suggesting that the decr ease in androstanediol glucuronide is not a consequence of the inhibit ory effect of progesterone on 5 alpha-reductase activity.