The research from a team at the University College London (UCL) Institute of Child Health, the research partner of Great Ormond Street Hospital in the UK, followed increasing concerns that many forms of neural tube defects (NTDs) are not responsive to folic acid supplementation.
The results published in the British Journal of Nutrition suggest adding inositol may be more effective than folic acid alone, but the scientists warned women should not stop taking folic acid, and any additional supplements should be taken under close medical supervision.
Researchers from the PONTI study (Prevention of Neural Tube defects by Inositol) - funded by the children’s medical research charity Sparks and the Medical Research Council - hope to follow up with a large-scale controlled trial to further establish the effects of this vitamin on NTD.
Of 99 women with a history of a NTD pregnancy, just under half agreed to be randomised to receive either a daily dose of 5 mg folic acid (the standard UK dose for women at high risk of NTD) plus 1 g of inositol, or 5 mg folic acid plus 1 g placebo, before conception and for three months after.
Many of the women who chose not to be randomised also took the inositol supplement at the studied dose of their own accord, and their pregnancy outcomes were recorded.
In total, thirty-three randomised pregnancies produced one NTD recurrence in the placebo plus folic acid group, and no recurrences in the inositol plus folic acid group. Of 22 pregnancies in the women who declined randomisation there were two NTD’s in women who took folic acid alone.
No adverse pregnancy events were associated with inositol supplementation in the randomised group.
UCL's Professor Andrew Copp told us the results were encouraging, but failed to provide a statistically significant difference because of the low participant numbers.
One of the aims of the PONTI pilot study was to assess the feasibility of a larger controlled trial, and a different trial design – perhaps multi-national - may be preferable, say the scientists.
“There was actually a surprisingly large number of women who declined to be randomised and just wanted to take the inositol, so that would clearly be a factor that would make it more difficult to do a randomised controlled trial – clearly you need a control group,” said Professor Copp.
Discussing future public health recommendations, he said: “The main folic acid trial was also of women with a history, and that was positive back in the 1980’s and that then led to all women having it recommended, although the evidence was for women at high risk, so it might go in the same way.
"We would do a further study, if that then showed us a positive outcome for women at high risk, maybe then the next thing would be to recommend it to all women, but that’s further down the line and I wouldn’t like to predict on that really.”
The study was one of over 1000 research projects currently being carried out at Great Ormond Street Hospital and the UCL Institute of Child Health, to help develop treatments and cures for conditions affecting children and adolescents.
Source: British Journal of Nutrition
Published online ahead of print, http://dx.doi.org/10.1017/S0007114515005322
“Inositol for the prevention of neural tube defects: a pilot randomised controlled trial”
Authors: N.D.E Greene et al.