“…Among the studies on women in their reproductive years, 62 provided information on the mean age or the age range of the sample. We analyzed the studies according to the above-mentioned 5 age sub-groups, and found a mean ovarian volume of 6.46 [5.83â7.09] ml in the 1st group (< 20 years; n = 9 studies) [ 29 , 42 , 48 b, 55 , 57 a, 73 a and b, 85 , 98 ], 5.79 [5.04â6.55] ml in the 2nd group (â„ 20 and < 25 years; n = 9 studies) [ 24 , 34 , 36 , 39 , 56 , 71 , 77 , 82 , 87 ], 6.02 [5.38â6.67] ml in the 3rd group (â„ 25 and < 30 years; n = 17 studies) [ 3 , 4 , 25 , 26 , 37 , 43 , 44 , 47 , 50 , 65 , 67 , 69 , 74 , 92 , 100 â 102 ], 5.98 [5.44â6.51] ml in the 4th group (â„ 30 and < 35 years; n = 18 studies) [ 28 , 38 , 46 , 51 â 53 , 61 , 64 , 66 , 70 , 78 â 80 , 84 , 86 , 96 , 97 , 99 ], and 6.28 [5.43â7.13] ml in the 5th group (â„ 35 years; n = 9 studies) [ 41 , 49 , 54 , 62 , 83 , 91 b and c, 94 , 95 ], respectively (Fig. 4 ).…”