Gestational Age-specific Reference Intervals for Androgens in Pregnancy

Androgen could impact cervical remodeling during pregnancy, and a higher level is associated with adverse pregnancy outcomes. A population-based gestation age-specific reference interval of total testosterone (TT), androstenedione (A4), and 17-hydroxyprogesterone (17-OHP) can help to diagnose maternal hyperandrogenism.

We enrolled 600 healthy Chinese women to obtain longitudinal serum samples across gestation. The serum androgen profile was measured by liquid chromatography-tandem mass spectrometry. The equations for medians of TT, A4, and 17-OHP were generated by MedCal, and the variances adjusted for 2-level modeling were generated by MLwiN, a system for the specification and analysis of a range of multilevel models.

A4 and TT levels increased across the gestation, and they closely correlated with each other (R = .90, P = <.001), whereas the 17-OHP level decreased from the 5th gestational week to the 16th gestational week and then increased afterward toward the end of pregnancy. Women diagnosed with preeclampsia (PE) were found to have a significantly higher level of A4, TT, and 17-OHP when compared with non-PE cases with P≤ .01, whereas mothers carrying male vs female fetuses have comparable levels of A4, TT, and 17-OHP.

The study highlights a methodology for constructing gestational age-specific TT, A4, and 17-OHP levels to provide a better interpretation of results in a cohort of healthy Chinese women. The observation in PE supports previous findings, and the higher levels of TT, A4, and 17-OHP were observed before the onset of PE.