Utilization
of the Maturation Index from a Pap Smear
The body manufactures three main kinds of
estrogen: estradiol, estrone, and estriol. Estrogens are promoters
of tissue growth,
stimulating the proliferation of cells in the reproductive organs
of women, particularly in the endometrium, the blood-rich lining
of the uterus that is shed during menstruation. The collective
effect of estrogen (the “estrogen effect”) in a woman’s
body can be estimated through evaluation of the squamous cell
layer that lines the vagina in a test known as a maturation index.
The relationship between hormone cycles and
the maturation of vaginal squamous cells were initially noted
by Rameriz and then
later by Papanicolaou in the 1920’s. Papanicolaou’s
research focused on the hormonal cycles of the female genitalia,
and the efficacy of exfoliative cytology in the detection of
cervical cancer was an incidental finding. A Maturation Index
(MI) is based on the assumption that the sex hormones estrogen,
progesterone and androgens (testosterone) bring about maturation
in squamous cells that can be detected by cytological examination.
The higher the number of mature cells (those designated ‘superficial’ and ‘intermediate’,
the higher the maturation index or estrogen effect in the body.
This provides doctors with information regarding levels of estrogen
and hormonal influence in their female patients.1
An MI is a ratio obtained through performing
a random count of three major cell types (parabasal cells,
intermediate cells
and superficial cells) that are shed from the squamous epithelium.
The cell count is expressed as a percentage that reads as follows:
MI= % parabasal cells, % intermediate cells, % superficial cells.
Parabasal cells are the least mature cells having not been affected
by estrogen or progesterone. Intermediate cells display mild
maturation, having been affected by progesterone, and superficial
cells display the most maturity, having been affected by estrogen.
A patient’s MI can vary on a daily basis, and of course
MIs vary from patient to patient. There are only two absolutes
when it comes to cellular patterns in an MI: the first is that
a predominance of parabasal cells indicates an absence of estrogen
stimulation, and second is that a predominance of superficial
cells indicates estrogen stimulation. Intermediate cells have
little clinical usefulness. The maturation index is useful for
the evaluation of therapies designed to treat vaginal hormonal
symptoms.2
The Maturation Index provides practitioners with a simply obtained
(samples are taken during the course of obtaining a pap smear)
sample that is easily analyzed to detect hormonal changes in
the vagina that are age-appropriate or an early sign of possible
hormonal related disease processes. The best samples for an MI
should be taken with a gentle scrape along the lateral wall of
the upper vagina at the level of the cervix. Cellular tissue
from this area accurately reflects the hormonal status at the
time of collection. Samples obtained must be free from signs
of inflammation (white blood cells) and endocervical cells, both
of which may falsely elevate the MI. MIs are useful for evaluating
hormonal function, evaluating cellular composition of the surface
layers of vaginal tissue which reflects the balance of estrogen
and progesterones effects on this tissue, and diagnosing conditions
that produce abnormal hormonal balance (pituitary gland dysfunction,
ovarian dysfunction, and hormone secreting tumors). Additionally,
MIs can detect the beginnings of endometrial cancer in menopausal
women, and have been used to screen for other cancerous process
such as vaginal adenosis and clear cell carcinoma in women who
were exposed in utero to diethylstilbestrol (DES), a synthetic
estrogen. The sensitivity of using a smear to determine a maturation
index in the diagnosis of vaginal intraepithelial neoplasia was
estimated to be at 83% percent in one recent study.3
Taking the following table into account,
practitioners can decide on a course of treatment for the patient
that presents with clinical
symptoms once this hormonal ‘cross check’ has been
measured. The maturation index is most useful for detecting hormonal
effects in menopausal and post-menopausal women, who may be experiencing
symptoms with and without treatment.4 Additionally, practitioners
may find the use of an MI in post-menopausal woman to be a good
screening tool for as-of-yet undetected vaginal cancers. Cellular
cytology is useful in this process, detecting cellular changes
prior to organ dysfunction, when the disease is in an advanced
state.
Various treatments for female hormonal health
and normalization exist, from standard hormone replacement
therapies (HRT) and
dietary and botanical medicines. Botanical medicines such as
phytoestrogens have been shown to increase the MI in women consuming
soy-rich diets over a 6-month period.5 Because of these effects,
soy and other phytoestrogens should be considered as part of
a preventative intervention in treating menopausal symptoms related
to estrogen deficiency. However, the use of the maturation index
should be correlated with clinical/symptomatic findings in order
to accurately treat the patient’s symptoms and take steps
to prevent worsening of symptoms or disease processes.
TYPICAL MATURATION INDEXES*
MI=% Parabasal Cells: % Intermediate Cells: % Superficial Cells
*This is an example only; actual patients will show marked
variability depending on history.
| Day 14 - Ovulation |
MI = 0:40:60 |
Indicates mostly estrogen stimulation. |
| Day 28 - Premenstrual |
MI = 0:70:30 |
Indicates mostly progesterone stimulation. |
| Menopausal |
MI = 0:100:0 |
Progesterone only, no estrogen. |
| Atrophic |
MI = 100:0:0 |
No progesterone or estrogen. |
| Child |
MI = 100:0:0 |
No progesterone or estrogen. |
| Puberty |
MI = 0:90:10 |
Mostly progesterone stimulation, minimal estrogen. |
| Pregnancy |
MI = 0:100:0 |
Progesterone only, no estrogen. |
| Post Partum |
MI = 90:10:0 |
Minimal hormonal stimulation. Ovarian function returns
in 6-8 weeks. |
1 McEndree B. Clinical application of the vaginal maturation
index. Nurse Pract. 1999 Sep;24(9):48, 51-2, 55-6.
2 Van der Laak JA, Schijf CP, Kerstens HM, Heijnen-Wijnen TH,
de Wilde PC, Hanselaar GJ. Development and validation of a computerized
cytomorphometric method to assess the maturation of vaginal epithelial
cells. Cytometry. 1999 Mar 1;35(3):196-202.
3 Davila RM, Miranda MC. Vaginal intraepithelial neoplasia and
the Pap smear. Acta Cytol. 2000 Mar-Apr;44(2):137-40.
4 Greendale GA, Zibecchi L, Petersen L, Ouslander JG, Kahn B,
Ganz PA. Development and validation of a physical examination
scale to assess vaginal atrophy and inflammation. Climacteric.
1999 Sep;2(3):197-204.
5 Chiechi LM, Putignano G, Guerra V, Schiavelli MP, Cisternino
AM, Carriero C. The effect of a soy rich diet on the vaginal
epithelium in postmenopause: a randomized double blind trial.
Maturitas. 2003 Aug 20;45(4):241-6.