Researchers at the UCL Institute of Child Health are
investigating a new treatment that could work alongside folic acid
to boost its effectiveness and prevent a greater proportion of
neural tube defects - such as spina bifida - in early
pregnancy.
A new study shows that the new treatment, when tested in mice,
reduced the incidence of neural tube defects (NTDs) by 85 per cent.
This new approach was also successful in preventing some kinds of
NTDs that are currently unresponsive to folic acid.
The researchers believe the findings could make way for future
trials in patients, to investigate whether the same level of
prevention can be achieved for human NTDs.
NTDs such as spina bifida and anencephaly are still among the
most common birth defects worldwide, affecting about 1 in 1,000
pregnancies with much higher rates in some countries.
Folic acid supplements taken in the very early stages of human
pregnancy, when an embryo's central nervous system is still
developing, currently prevent a proportion of NTDs (20-80 per cent
depending on geographic region). Folic acid works by helping the
embryo's neural tube to close normally, which is an essential step
of development (failure of this process results in NTDs). However,
a significant number of NTDs are unresponsive to folic acid
supplements.
One reason why folic acid might not always be effective is that
a 'genetic blockage' can occur in the way folic acid is handled, or
metabolised, in cells. In such cases, even if folic acid is taken
early in pregnancy it is blocked from having the desired effect on
the embryo. The new treatment involves supplementing with
'nucleotides', which are needed to make DNA as cells divide in the
growing embryo. Nucleotides can bypass the blockage in the way
folic acid is handled, ensuring the growth of crucial cells in the
embryo.
NTDs are likely to have many possible causes and the team
considers that the most effective way to reduce the risk of NTDs is
to use a combination of different treatments. In previous studies
they found that a particular vitamin, inositol, has a protective
effect and this is being tested in a clinical trial.
Similar studies are now proposed for the 'nucleotide' treatment,
and researchers envisage that a single tablet could eventually be
developed for women planning a baby, which would contain folic acid
and the new protective compounds.
Commenting on the new research, Nicholas Greene of the Institute
of Child Health, said: "We are still in the early stages of this
research, but we hope that these promising results in mice can
eventually be replicated with human NTDs. If it is found to be
effective, this nucleotide treatment could boost the effects of
folic acid and offer expectant mothers an even more reliable
safeguard against relatively common defects like spina bifida."
Professor Greene added: "While we continue our research into
this new treatment, it's important to emphasise that folic acid
supplements remain the most effective prevention against NTDs
currently available for women who are planning a baby. While we are
greatly encouraged by these new findings, I would strongly urge
women to continue taking folic acid in its current form until we
reach a point where additional supplements might become
available."
The paper, Nucleotide precursors prevent folic acid-resistant neural tube
defects in the mouse, is published inBrain.