Which of the following statement regarding Prolactin levels is TRUE?

Maternal plasma levels of prolactin increase markedly during normal pregnancy and concentrations are usually 10-fold greater at term--about 150 ng/mL--compared with nonpregnant women. Paradoxically, plasma concentrations decrease after delivery even in women who are breast feeding. During early lactation, there are pulsatile bursts of prolactin secretion in response to suckling. Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 5. Maternal Physiology. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.