PLACENTA IS ELECTRICALLY ACTIVE. “In placenta, there is evidence that steroid hormones, which are present in high concentrations during pregnancy in humans, have some influence in secretory and absorbing processes … the control of Maxi-chloride channels by steroid hormones may be of great importance in placental physiology.”
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300006