Neurosteroid involvement in threatened preterm labour

Area of Science:

• Neuroendocrinology
• Obstetrics
• Neuropharmacology

Background:

• The neurosteroid allopregnanolone influences oxytocin expression via the GABA_A receptor.
• The role of neurosteroid levels and GABA_A receptor function in preterm labor risk is not understood.

Purpose of the Study:

• To investigate whether neurosteroid levels and GABA_A receptor function are associated with threatened preterm labor (TPL) in pregnant women.

Main Methods:

• Prospective study of pregnant women with (n=16) or without (n=20) TPL.
• Measured plasma levels of allopregnanolone, progesterone, and oxytocin.
• Assessed GABA_A receptor function using saccadic eye velocity test (SEVT).

Main Results:

• Plasma oxytocin levels were significantly higher in the TPL group.
• Allopregnanolone and progesterone levels did not differ between groups, but oxytocin showed a negative association with allopregnanolone in the TPL group.
• GABA_A receptor function, as measured by SEVT, was similar in both groups.

Conclusions:

• Peripheral neurosteroid levels were not altered in women with TPL, despite increased oxytocin.
• GABA_A receptor function appeared unchanged in women experiencing TPL.
• Further investigation using GABA_A receptor agonist challenge tests is recommended to confirm GABA_A receptor function reliability.