The maturation index (MI) described the relative proportion of parabasal, intermediate and superficial cells in vaginal cytology. This reflects the level of estrogen effect on cellular maturation. This can be quantitated using the maturation value (MV).


Specimen: Vaginal cytology collected from the vaginal pool or lateral vaginal wall and stained with the Papanicolaou stain. Superficial cells are a dark eosinophilic color with pyknotic nuclei, while parabasal cells are light greyish blue with relatively large nuclei. Groups of 3 or more cells should not be counted. At least 100 cells should be counted.



(1) total number of cells counted

(2) number of parabasal cells

(3) number of intermediate cells

(4) number of superficial cells


percent of each cell type =

= (number of cell type counted) / (total number of cells counted) * 100


maturation index =

= P : I : S



• P = percent parabasal cells

• I = percent intermediate cells

• S = percent superficial cells


maturation index =

= ((percent parabasal cells) * 0) + ((percent intermediate cells) * 0.5) + ((percent superficial cells) * 1) =

= (percent superficial cells) + (0.5 * (percent intermediate cells))



• SUM(P + I + S) = 100

• minimum maturation value: 0 (all parabasal cells)

• maximum maturation value: 100 (all superficial cells)

• The typical maturation index for a normal woman at ovulation is 0:35:65. The corresponding maturation value would be 82.5. A normal menstruating woman should have a maturation value > 50.

• The typical maturation index for a postmenopausal woman without estrogen replacement and marked atrophy is 90:10:0. The corresponding maturation value would be 5.


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