A team of British scientists have
figured out a way to predict miscarriage in pregnant
women with 94% accuracy. The striking early results
of their study are published in the March 12 issue of
"The aim of this study was to investigate
the mechanisms involved in unexplained miscarriages
and how these could be modulated to improve outcomes,"
explains lead author Dr Justin Konje, head of the clinical
division of obstetrics and gynecology at the University
of Leicester, via email to NRM. But finding that
one little molecule can predict miscarriage so well
opened up a whole other avenue of study, namely the
development of a miscarriage test.
Up to 25% of all pregnancies end
in miscarriages, according to some Canadian estimates.
Some diseases, like diabetes, or lifestyle habits such
as smoking raise the risk. But for many women, there's
no explanation for their miscarriages.
The key molecule to look for happens
to be an endogenous "cannabis" called anandamide. "Anandamide
is crucial to various stages in pregnancy," says Dr
Konje. It acts as a communicator between the embryo
and the endometrium, ensuring that the embryo is developed
enough for implantation and that the endometrium is
prepped to receive it, he adds.
The researchers gleaned that information partly from
animal studies and decided to look at anandamide levels
in 45 pregnant women who were at risk of miscarriage.
These are women who presented with bleeding in early
pregnancy but still had a viable baby. They tested the
women's blood for anandamide and found that the women
who miscarried had twice as much of the molecule than
those who went on to have a healthy, full-term pregnancy
3.47 nM versus 1.7 nM.
"The pilot data we've generated
has a 100% negative predictive value for miscarriage,
so any woman with a low level can be reassured that
she will have a live birth," says Dr Konje. And that's
even if she has some subsequent bleeding. Armed with
this knowledge, the need for repeat scans and extra
visits to the doctor can be minimized, which will cut
the overall healthcare cost, he points out.
As for the high level women, the
anandamide test pinpointed the doomed pregnancies with
94% accuracy. Although two of the high anandamide women
went on to have a live birth, one of them developed
pre-eclampsia and delivered at 33 weeks.
"For some women, knowing that the
pregnancy is destined to fail may help them come to
terms with the eventual outcome," Dr Konje suggests.
And though science has no tools now to alter that outcome,
Dr Konje and his team are starting to look at how anandamide
levels can be changed to favour a live delivery
but he's keeping quiet until more data is available.
The British team wasn't the first to figure out a connection
between anandamide and miscarriages. An April 2000 Lancet
study by Italian researchers found that women who had
low levels of fatty acid amide hydrolase (FAAH)
an enzyme that breaks down anandamide went on
But no predictor test came of that
study, partly because of the difficulties in measuring
FAAH levels, speculates Dr Konje. "The enzyme was quantified
from peripheral mononuclear blood cells. The process
is laborious and will be difficult to apply in clinical
practice," he says.
Dr Konje and colleagues decided
to go straight to the source: anandamide. Right now,
isolating it from blood samples can take up to 12 hours,
but the team hopes to develop a test that will spit
out results in 10 to 15 minutes. "The next step is to
confirm the observations [via a larger study]," says
Dr Konje. Once that's done, the plan is to investigate
the best way to test within the next three years.