Comparison of Pregnancy Stress Between In Vitro Fertilization/Embryo Transfer and Spontaneous Pregnancy in Women During Early Pregnancy. - Fen-Fen Shih; Chung-Hey Chen; Chia-Yi Chiao; Chi-Rong Li; Pi-Chao Kuo; Te-Jen Lai (Journal of Nursing Research (Lippincott Williams & Wilkins), 2015)