Feminine Hygiene
Prof A. Kulenthran
01-20-2008

The silent guardian of the vaginal ecosystem is an acid-producing
bacteria.

THE vagina and its exterior, the vulva, are the most intimate part of
a woman's body. Measuring about seven centimetres, the vagina is a
muscular organ that connects the uterus to the outside. It is the path
to procreation. Its inner lining, referred to as the mucosa, is a
multi-layered cell structure. This lining needs to be kept moist.

What is little realised however is that the vagina possesses an
ecosystem of its own. It is a dynamic environment and the vaginal
mucosa in particular, undergoes changes with differing stages of a
woman's life.

What is seldom understood too is that the consequences of any change
in this eco-system can have a profound effect not only on the vagina
itself, but also to the vulva.

Evolution of the vaginal ecosystem

Before birth, the vaginal lining is only single layered. That does not
pose a problem, because at that stage there is no need for protection
against any ascending infection.

But at birth the vagina becomes exposed. The cells of the lining
become flattened and multi-layered so as to form an effective barrier
against trauma or infection.

How the Doderleins bacillus keeps the vaginal environment healthy.
Besides this physical barrier, the ecosystem also evolves so as to
provide a biochemical barrier to any infection. Thankfully, the
mother's oestrogens are still circulating in the child and these
hormones encourage the cells to store glycogen, a sort of sugar.

There is an important purpose for this because, over time, the origins
of which are still unclear, the vagina becomes colonised by an acid
producing bacteria named Doderleins bacillus. Its scientific name is
Lactobacillus acidophilus.

Living up to its name, these bacilli are capable of using the glycogen
stored in the cells as a substrate to render the pH of the vagina
acidic by producing lactic acid.

By convention, a pH of 7 is neutral. Anything above that is alkaline
and anything below is acidic. The lower it is, the more acidic the
environment and the more protection it affords.

The lactic acid produced renders and maintains the pH of the vaginal
secretions to be between 3.8 to 4.2. This has a bonus effect - it
promotes further growth of the bacillus and a favourable cycle is set
in motion.

However as the child grows, the maternal oestrogens begin to deplete.
Furthermore, the ovaries have not begun to secrete oestrogens. This
results in reducing the amount of lactic acid being produced. The
child may therefore be prone to infection.

Fortunately the main culprit for vaginal infections - sexual
intercourse - does not occur and most children sail through without
any untoward incident, unless of course there are poor toilet habits.

Changes during puberty

But with puberty, the scenario changes drastically. The out-pouring of
oestrogen from the ovaries stimulates the cells to store glycogen and
reactivate the Doderleins bacillus. The vaginal pH becomes acidic and
protects it from infection; it is nature's way of protection because
puberty come the child-bearing years.

During each menstrual cycle too, the hormones undergo cyclical
changes. In the first half, oestrogens dominate, but during the second
half, another hormone, progesterone dominates. Progesterone renders
the cells less likely to store glycogen and indirectly, affects the
acidity of the environment. Infection is more likely. Thankfully, the
period is short.

Changes during pregnancy

The next change comes with pregnancy. The vagina becomes very vascular
and the secretions are more copious. However in pregnancy the dominant
hormone is not oestrogen but progesterone. This hormone counteracts
the effect of oestrogen.

Together with the increased sugar levels in the vaginal secretions
that occur in pregnancy, it creates a milieu that promotes yeast
infection, in particular the Candida species. Not surprisingly
therefore, it is an infection commonly seen in pregnancy.

Changes during menopause

The last significant change in the vaginal ecosystem comes with the
menopause. The oestrogen level drastically falls. The vaginal mucosa
thins out and the cells become devoid of glycogen. The acidic
protection is lost.

The vagina now becomes vulnerable to infections. Fortunately, sexual
intercourse at this stage is less frequent and the change in lifestyle
acts as a check and balance.

Why is feminine hygiene important?

This is because developmentally, the vagina and the anal canal have a
common origin and it was inevitable therefore that the two would be
closely related.

Therein lay the problem. The surrounding exterior is very likely to be
contaminated with bacteria or other organisms and the vagina provides
a perpetual "open-house" to this exterior.

Whether from poor feminine hygiene or from repeated sexual
intercourse, ascending infection is always a risk.

The vagina is able to keep these ascending infections at bay because
of its acidic environment. But if this defence is lost, the
opportunistic infections, either bacteria or fungi, are capable of
taking over. There is a compounding effect to this.

These infections tend to raise the pH of the vaginal milieu and this
further inhibits the growth of the acidophilus bacteria. A vicious
cycle is set in motion.

The answer to the problem therefore is to always be on top of it - be
proactive. A knee-jerk response would be to use antiseptics. But this
would remove all, the good and the bad bacteria.

A more sensible and longer lasting way would be to maintain a
consistent and favourable vaginal and vulval ecosystem, the central
role being to provide for an acidic environment.

Common sense dictates that if lactic acid plays a central role in
doing so, enhancing the vaginal milieu with washings of lactic acid is
the logical choice.

Furthermore, it promotes an appropriate environment both for
maintaining and promoting the growth of the Doderleins bacillus.

Prof A. Kulenthran is a consultant obstetrician & gynaecologust. This
article is courtesy of sanofi-aventis.

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