Changes to the communities of microbes
living in the reproductive tract of pregnant women could help to spot women at
risk of giving birth prematurely, according to Imperial College London
researchers.
A study of hundreds of women, carried
out at Imperial College London, found that subtle changes to the bacteria
present in the vagina were strongly associated with the mother's waters
breaking early and preterm birth -- the baby being born before 37 weeks.
According to the researchers, the
findings show that a shift away from the usual healthy balance of vaginal
bacteria was associated with waters breaking early, and could have an impact on
the health of mother and baby, including increasing the risk of sepsis for
newborns.
Samples were collected from a
prospective group of 250 pregnant women with and without risk factors for
giving birth prematurely -- such as having a history of preterm birth or
miscarriage -- of which 27 did in fact have a premature birth. They also
collected samples from a second, smaller group of 87 women who presented to
hospital with premature membrane rupture. All patients were seen at Queen
Charlotte's and Chelsea Hospital and Chelsea and Westminster Hospital.
Previous research has shown that over
the course of pregnancy the bacteria that colonise the vagina become less
diverse and are dominated chiefly by Lactobacillus species, the same type of
bacteria found elsewhere in the body including the gut and mouth.
Analysis of the team's samples revealed
that premature membrane rupture was associated with a shift in microbiota, with
a drop in Lactobacillus and an increase in other types of bacteria, including potentially
harmful bugs such as Staphylococcus and Streptococcus.
The team also analysed samples from the
small group of women with premature rupture before and after the preventative
antibiotic treatment -- oral erythromycin, four times a day for 10 days. Swabs
were taken before treatment and then at 48 hours, one week and two weeks.
For those women whose microbial makeup
was dominated by Lactobacillus before the treatment, the antibiotics resulted
in a decline in Lactobacillus and a greater diversity of bugs. However, in
those women with reduced Lactobacillus to begin with, the treatment was
beneficial in some, reducing the amount of potentially harmful bacteria as
well.
See:
Posted by Dr. Tim Sandle