Do neuroactive steroids cause fatigue in pregnancy?

To elucidate factors causing widespread fatigue in pregnancy we studied plasma samples from 23 healthy pregnant volunteers, measuring endogenous neuroactive steroids, endozepines and benzodiazepines by receptor binding assays. The samples were taken at different gestational ages and the women were asked about their feeling of fatigue at the time of sample collection. We found a significant correlation between fatigue in pregnancy and presence of neuroactive steroid-like activity, but could not detect endogenous benzodiazepine-like factors. These results suggest that neuroactive steroids may be involved in fatigue during pregnancy. Their site of synthesis and their biological role remain unclear.