Patterns of Plasma Corticotropin-Releasing Hormone, Progesterone, Estradiol, and Estriol Change and the Onset of Human LaborSmith, Roger; Smith, Julia I.; Shen, Xiaobin; Engel, Patricia J.; Bowman, Maria E.; McGrath, Shaun A.; Bisits, Andrew M.; McElduff, Patrick; Giles, Warwick B.; Smith, David W. · The Journal of Clinical Endocrinology & Metabolism · 2009