1. Logarithmic curves depicting initial level and rise of serum beta human chorionic gonadotropin and live delivery outcomes with in vitro fertilization: An analysis of pregnancies 
Mousa I. Shamonki, M.D., John L. Frattarelli, M.D., Paul A. Bergh, M.D., Richard T. Scott, M.D. 
Fertility and Sterility 
Volume 91, Issue 5, Pages (May 2009)
DOI: /j.fertnstert
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Logarithmic curves for initial β-hCG and live-birth rates for groups A–D. Group A = age <35 years; group B = age 35–37 years; group C = 38–40 years; group D = 41–42 years.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

3. Figure 2
Logarithmic curves for initial and percent rise in β-hCG and live-birth rates for all age groups combined.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions