Bacteria may play a role in preterm premature rupture of
fetal membranes, reveal researchers.
This finding was published online in the recent edition of PLOS ONE.
when the baby is delivered before 37 weeks of pregnancy. Preterm delivery puts
the baby at a number of health risks and may even affect the survival of the
baby. Thus, it is necessary to
understand various reasons for preterm delivery and control them where
Recent research suggests that preterm premature
rupture of membranes (PPROM), which could trigger preterm delivery, could be
possibly due to bacteria. Normally,
fetal membranes - the chorion and the amnion - surround the fetus
amniotic fluid. A break in the
membranes, also referred to as breaking of the bag of waters, is often followed
by the delivery of the fetus.
The study included 48 women, who were divided into
three groups. The first group consisted
of women with PPROM between 24 to 34 weeks of gestation
confirmed by various tests. The second group consisted of 16 preterm women
between 24 to 34 weeks of gestation, who either underwent labor or delivered by
cesarean section. The third group
consisted of 18 term women between 37 to 41 weeks of gestation who again either
underwent labor or delivered by cesarean section.
Fetal membranes were collected from the rupture site
after delivery in those who underwent labor
and a site
over the cervix in those who underwent caesarian section
. Another sample was also collected from an
intact site far away from the rupture site, referred to as the distant
site. Membrane thickness was measured
in each case. The Fluorescence in situ
Hybridization (FISH) test was used to detect the presence of bacteria in the
In the PPROM group, the mean time duration from the
rupture of membranes to the delivery was 13.1 days. Antibiotics were given following the rupture for around 7 days.
The researchers found that the chorion layer of the fetal
membranes was thinner at the site of rupture in all patients as compared to the
distant site. Patients with PPROM had
thinning of the chorion at the rupture site as well as the distant site,
indicating an overall thinning of the membrane in patients with PPROM.
The mean bacterial count was higher at the rupture
site than the distant site in all patients.
Though all the samples had bacteria
the counts were higher in those with PPROM.
Higher bacterial counts were associated with thinner chorion in these
The study thus suggests that that the chorion layer
of the fetal membrane is thinner in patients with PPROM throughout the fetal
membrane. It also suggests that
bacteria may play a role in the thinning of the chorion layer.
The researchers suggest that further studies should
be done to identify the bacteria found in PPROM
patients. If specific bacteria are
found to be associated with PPROM, diagnosing and treating such as infection
during pregnancy could possibly reduce the chances of premature birth and
therefore its consequences.
Causes of Premature Birth
The exact cause of premature birth is not known. Some
of the factors that increase the risk of premature birth are:
Illnesses like pre-eclampsia
disease and infections in the mother
, drug abuse
or excessive intake of alcohol
A weak cervix, the lower part of the uterus
Placenta previa, a condition where the placenta is
located lower than normal
Physical injury or mental stress
Fortner KB et al. Bacteria Localization and Chorion Thinning among Preterm
Premature Rupture of Membranes. DOI: