1. Seasonal variability in fertilization and embryo quality rates in women undergoing IVF 
Nathan Rojansky, M.D., Abraham Benshushan, M.D., Samuel Meirsdorf, M.D., Aby Lewin, M.D., Neri Laufer, M.D., Anat Safran, Ph.D. 
Fertility and Sterility 
Volume 74, Issue 3, Pages (September 2000)
DOI: /S (00)

2. FIGURE 1
The seasonal variability, in assisted reproduction, of the three outcomes studied. (A) The seasonal changes in fertilization rate; F(3,301) = 2.80; P<.04. (B) The seasonal changes in quality-A embryos; F(3,299) = 3.81; P<.05. (C) Seasonal variability in conception rate (per embryo transfer); N.S.
Rojansky. Seasonal variation in human reproduction. Fertil Steril 2000.
Fertility and Sterility  , DOI: ( /S (00) )

3. FIGURE 2
The correlation between (A) monthly fertilization rates and (B) the changes (Δ increase/decrease) in monthly light hours (as measured at the 22nd day of each month); r = 0.18; P<.05. Dashed line denotes mean annual fertilization rates (±SD).
Rojansky. Seasonal variation in human reproduction. Fertil Steril 2000.
Fertility and Sterility  , DOI: ( /S (00) )

4. FIGURE 3
The correlation between (A) monthly rates of quality-A embryos and (B) the monthly changes (Δ increase/decrease) in light hours (at 22nd day of each month); r = 0.13; P<.05. (C) Correlation with the absolute number of light hours; r = 0.15, P<.05. Dashed line denotes mean annual rate (±SD) of quality-A embryos.
Rojansky. Seasonal variation in human reproduction. Fertil Steril 2000.
Fertility and Sterility  , DOI: ( /S (00) )