Bacterial vaginal infections are a pain in the
bottom anytime, but during pregnancy, they can actually
cause other serious problems with respect to the outcome
of the pregnancy. Bacterial vaginosis is associated
with preterm labor, premature rupture of the bag of
waters which leads to preterm labor, infection of
the amniotic fluid, placenta and baby during labor.
In fact it is estimated that 15%-20% of all pregnant
women have bacterial vaginosis, BV.
A recent article, Hammill H: Bacterial vaginal infections
in the pregnant patient. The Female Patient, 1999
(Aug);suppl 25-28, looked at the diagnosis and management
of BV infections during pregnancy.
Are there different types of bacterial vaginal
infections?
There are two main types of bacterial vaginal infections,
a general mixed bacteria infection called bacterial
vaginosis (BV) and a streptococcal bacterial vaginosis.
Either one of them can be associated with complications
for a pregnant woman. BV can lead to preterm labor
and delivery. Streptococcal vaginitis can do the same
and, in addition, it can cause an infection in the
newborn baby. This is a very serious infection and
about 4% of babies who get this infection die and
the ones who survive have other serious infections
in the brain, lung and bone.
What is a streptococcal vaginosis?
Vaginosis caused by streptococcus presents as a creamy,
white discharge. There is not usually a burning of
the vulva as there is with yeast infection and the
discharge is not very odorous like a bacterial vaginosis.
If the doctor looks at the discharge under a microscope,
there are no white blood cells and no lactobacilli,
the normal bacteria of the vagina.
There are several streptococcal species that can
be present in the vagina, group A, B and D strep.
About 70% of strep vaginosis is due to group B and
about 30% are due to group D. Group A infections are
rare.
Strep vaginosis can occur spontaneously but very
often it is caused by the antibiotic treatment given
for bacterial vaginosis. Metronidazole (Flagyl®)
is the usual treatment for BV but it does not treat
strep, therefore an overgrowth of streptococcus frequently
occurs. This is such a problem that one vaginal cream,
clindamycin vaginal cream, which was frequently used
for bacterial vaginosis during pregnancy, is no longer
approved because it results in a strep vaginosis.
Oral clindamycin is still approved for bacterial vaginosis
and there is no evidence that it produces a strep
overgrowth.
Should I be routinely tested for bacterial
vaginosis during pregnancy?
Any woman who has had a previous streptococcal vaginal
infection during pregnancy or even a history of preterm
labor or preterm rupture of the membranes during a
previous pregnancy should be tested again or even
just empirically treated as if she had such an infection.
This testing should be both for bacterial vaginosis,
by microscopic exam of vaginal secretions or special
amine spot tests, and for streptococcal vaginosis
by streptococcal bacterial cultures or reliable screening
test. The testing or treatment for bacterial vaginosis
should take place after 16 weeks pregnancy and the
testing or treatment for streptococcal vaginosis should
take place at 35-37 weeks or anytime during presentation
for labor, suspected labor or with a history of rupture
of the bag of waters (membranes) prior to the onset
of labor.
For most lower risk women, there are generally two
different strategies:
Bacterial vaginosis
Aggressively diagnose and treat any pregnant woman
for vaginosis who has symptoms of vaginal discharge,
odor or vulvar irritation
Routinely screen after 16 weeks pregnancy for BV,
and treat and follow-up those with BV to make sure
recurrences are minimized (note that this approach
has not yet been excepted as cost effective by many
providers but it makes sense if 15-20% of all pregnant
women have BV and up to 50% are completely asymptomatic)
Streptococcal vaginosis
Screen all low risk pregnant women for group B streptococcus
at 35-37 weeks gestation and those who are positive
should be treated for active infection during labor
automatically
Screen or treat only high risk patients with a past
history of preterm complications or with intrapartum
fever of more than 100.4 deg F (38.0 deg C) or membrane
rupture more than 18 hours
If bacterial vaginosis causes complications
of pregnancy, will it also cause difficulty conceiving
or cause miscarriage?
No, it does not seem to cause difficulty getting pregnant.
Yes, it is associated with an increased incidence
of miscarriage. A recent study, Ralph SG, Rutherford
AJ, Wilson JD: Influence of bacterial vaginosis on
conception and miscarriage in the first trimester:
cohort study.BMJ 1999 Jul 24;319(7204):220-3, showed
a miscarriage rate of 31.6% in women with bacterial
vaginosis compared with 18.5%, a normal background
rate, in women with normal vaginal bacteria.
Is there anything I can do during pregnancy
or before to prevent or detect bacterial vaginosis?
Self-care diagnosis and treatment are just beginning
to be introduced into standard medical therapy recommendations.
A study in Germany to prevent premature births used
a vaginal pH glove that women used to check their
vaginal pH twice a week during pregnancy. An elevated
pH of over 4.7 (pH is a measure of acidity of the
vaginal secretions) was associated with bacterial
vaginosis. It was then treated with lactobacillus
tablets (normal vaginal bacteria) or antibiotics and
the incidence of preterm labor and very low birthweight
infants was reduced. The vaginal pH glove is not yet
available in the U.S. but it may soon be.
Tablets containing lactobacillus to place in the
vagina to restore the normal bacteria flora are available
at many pharmacies and health food stores. Doctors
would not recommend that you use them routinely unless
there is a need for them because routine use of douching
has been shown to actually produce more bacterial
vaginosis than it cures. Thus the concept of putting
any medical substance into the vagina on a routine
basis if not really needed is thought to be able to
potentially cause alterations that can lead to an
infection.
A better strategy might be to work with your doctor
to be sure to check vaginal secretions either before
conception or after about 16 weeks of pregnancy (
because there is a very low incidence of new occurrence
of vaginosis after 16 weeks). The doctor may do a
microscopic exam or just check a vaginal pH. If either
are positive, discuss antibiotic treatment for this
and then consider following up to make sure the infection
is gone. If you have trouble with recurrent BV, ask
the doctor if you can use the vaginal lactobacillus
tablets to try to decrease the chance of recurrence.
It also goes without saying that douching is not something
you should do during pregnancy and even when not pregnant,
you should consider not douching on a routine basis.
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