1. Optimizing natural fertility: a committee opinion
Fertility and Sterility 
Volume 100, Issue 3, Pages (September 2013)
DOI: /j.fertnstert
Copyright © 2013 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Pregnancy rate (per 1,000 women) in various populations at different times in history. Modified from Larsen et al. (4). The 10 populations (in descending order at age 20 to 24) are Hutterites, marriages 1921 to 1930 (solid triangles); Geneva bourgeoisie, husbands born 1600 to 1649 (solid squares); Canada, marriages 1700 to 1730 (solid circles); Normandy, marriages 1760 to 1790 (open circles); Hutterites, marriages before 1921 (open squares); Tunis, marriages of Europeans 1840 to 1859 (open triangles); Normandy, marriages 1674 to 1742 (solid circles); Norway, marriages 1874 to 1876 (open squares); Iran, village marriages, 1940 to 1950 (solid triangles); Geneva bourgeoisie, husbands born before 1600 (open circles).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2013 American Society for Reproductive Medicine Terms and Conditions

3. Figure 2 Probability of pregnancy with a single act of intercourse.
Modified from Dunson et al. (14).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2013 American Society for Reproductive Medicine Terms and Conditions

4. Figure 3
Probability of pregnancy by cycle day, involving recurrent intercourse, by age.
Data from Stanford and Dunson 2007 (16).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2013 American Society for Reproductive Medicine Terms and Conditions

5. Figure 4
Estimates of the probability of conception according to vaginal secretion observations on the day of intercourse.
Data from Scarpa et al., 2006 (18).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2013 American Society for Reproductive Medicine Terms and Conditions