1. Menstrual cycle length is an age-independent marker of female fertility: results from treatment cycles of in vitro fertilization 
Thomas Brodin, M.D., Torbjörn Bergh, M.D., Ph.D., Lars Berglund, M.Sc., Nermin Hadziosmanovic, M.Sc., Jan Holte, M.D., Ph.D. 
Fertility and Sterility 
Volume 90, Issue 5, Pages (November 2008)
DOI: /j.fertnstert
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
The decline of mean MCL, days ± SEM, in relation to increasing age at OPU, illustrating the subtle but still significant difference between the younger and older women in the study group. Analysis was made on the first treatment only. Ptrend<.0001.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

3. Figure 2
Pregnancy rate per ET in relation to stratified MCL, unadjusted and adjusted for age. Mean values ± SEM (SEM not for adjusted values). Ptrend<.0001 for both.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions