How does cfs relate to pregnancy?

CFS: Chr. Fatigue S. Chronic fatigue syndrome is poorly understood. Many things have been blamed to cause it i.e. Epstein barr virus, cyromegalovirus, toxoplasmosis. Most of the time we don't find a cause. During pregnancy many hormones are produced by the placenta and there is some biochemical interaction between fetus and mother. In general pregnancy causes fatigue especially at the end. Pregnancy triggers cfs?
Chronic Fatigue. There is no data to state that chronic fatigue syndrome is correlated with pregnancy or any risk to the fetus.