1. Effect of preovulatory progesterone elevation and duration of progesterone elevation on the pregnancy rate of frozen–thawed embryo transfer in natural cycles 
Vivian Chi Yan Lee, M.B.B.S., Raymond Hang Wun Li, M.B.B.S., Joyce Chai, M.B.B.S., Tracy Wing Yee Yeung, M.B.B.S., William Shu Biu Yeung, Ph.D., Pak Chung Ho, M.D., Ernest Hung Yu Ng, M.D. 
Fertility and Sterility 
Volume 101, Issue 5, Pages (May 2014)
DOI: /j.fertnstert
Copyright © 2014 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Clinical and ongoing pregnancy rates of subjects with no P rise, or 2 day, 2 days, and 3 days of P rise. CPR = clinical pregnancy rate; OPR = ongoing pregnancy rate; P4 = progesterone.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2014 American Society for Reproductive Medicine Terms and Conditions