Folic acid supplements in pregnancy and birth outcome: re-analysis of a large randomised controlled trial and update of Cochrane review. Reduction of incidence of prematurity by folic acid supplementation in pregnancy. A randomised trial of low dose folic acid to prevent neural tube defects. The Irish Vitamin Study Group. Influence of routine administration of folic acid and iron during pregnancy. A prophylactic supplementation of iron and folate in pregnancy. Double-blind randomised controlled trial of folate treatment before conception to prevent recurrence of neural-tube defects. Randomized trial of a physician-based intervention to increase the use of folic acid supplements among women. Effect of time of initiation and dose of prenatal iron and folic acid supplementation on iron and folate nutriture of Korean women during pregnancy. Multicentric study of efficacy of periconceptional folic acid containing vitamin supplementation in prevention of open neural tube defects from India.
Periconceptual folic acid prevents neural tube defects. The effect of folic acid taken throughout pregnancy is unclear, however. We re-analysed data from a large randomised controlled trial performed between 1966 and 1967 and combined the results with those from trials included in a Cochrane review. A total of 2928 women were randomised: 1977 were allocated to placebo, 466 to folic acid 200 microg/day and 485 to folic acid 5 mg/day. Folic acid supplementation was not associated with any difference in mean birthweight, placental weight or gestational age. When combined with trials in the Cochrane review folic acid at high doses was associated with reduced risk of low birthweight (pooled relative risk 0.73 [95% CI 0.53, 0.99]). We found no conclusive evidence of benefit for folic acid supplementation in pregnant women given from time of booking onwards. Folic acid administered to pregnant Bantu, whose diet is low in folate, was associated with a significant reduction in the incidence of prematurity. No such effect could be demonstrated in White patients subsisting on an average Western diet. This suggests that folate deficiency may contribute to the "pregnancy wastage" in populations whose dietary folate intake is low, and is a further indication for folic acid supplementation during pregnancy in these groups. A randomised trial was initiated in Ireland in 1981 to determine if periconceptional supplementation with either folic acid alone or a multivitamin preparation alone could reduce the recurrence risk of neural tube defects (NTDs) in women with a previously affected pregnancy from 5.0% to 1.0% or less. The trial was concluded before the initial target number of study subjects was reached and without a clear treatment effect being observed. A total of 354 women were randomised to receive one of three treatments: folic acid, multivitamins without folic acid, and folic acid plus multivitamins. At the end of the trial 257 women had had a first trial pregnancy outcome (261 infants/fetuses) where the presence or absence of NTDs was ascertainable. There was one NTD recurrence in the 89 infants/fetuses of women in the multivitamin group and no recurrence in the 172 infants/fetuses of women in the folic acid groups, a non-significant difference. Otherwise eligible women who were pregnant when first contacted constituted a non-randomised control group; there were three recurrences among the 103 infants in this group. The difference in the recurrence rate between the folic acid groups and the non-randomised controls was statistically significant but we have reservations about the validity of this comparison. Although our findings do not provide clear evidence of a protective effect of folic acid supplementation they are consistent with those of the Medical Research Council (MRC) trial which demonstrated the efficacy of folic acid in preventing recurrence of NTDs and they raise the possibility that folic acid may be protective at a much lower dosage than that used in the MRC trial. Haematological and folic acid status were assessed in 200 women in the 6th month of pregnancy. Folic acid deficiencies with no or little haematological impairment were found in one third of the cases, and their occurrence increased when the socioeconomic level was low. During the last trimester of pregnancy, the women were given either iron alone or iron and folic acid supplementation. In the mothers, the rise of folate values in serum and red blood cells, in the folic acid-supplemented group, had no obvious haematological consequences, showing that iron therapy alone can, in developed countries, prevent the anaemia in pregnancy. In the infants, there was no difference in the haematological indices, whatever the mothers' treatment had been. However, a significant difference appeared for the gestational age and, therefore, the height and weight. Folic acid supplementation during pregnancy increased its duration by virtually 1 week. The supplementation of iron and folic acid were studied in 567 pregnant women with 18 and 26 weeks of gestation. Sixty mg and 180 mg of iron were given daily to pregnant women of group I and group II respectively while 180 mg of iron and 5 mg folic acid were given to group III. The Hb values increased significantly in group II and III after supplementation for 1 1/2 months, however if supplementation was extended for 3 months, highly significant increase in Hb levels were observed in all these groups. These findings indicated that in supplementation for a shorter period, i.e. 1 1/2 months at least 180 mg of iron was needed, and only 60 mg of iron was sufficient to increase Hb levels for a supplementation of 3 months. Vitamin B12 deficiency was not detected in pregnant women both before and after supplementation with iron and iron plus folate for 3 months. It was suggested therefore that perhaps it was not necessary to supplement vitamin B12 to Thai pregnant women. In this study 15% of pregnant women had low serum folate with normal red cell folate level, and a greater number of women with low serum folate concentrations were observed after supplementation with iron alone for 3 months. However, increased serum folate and red cell folate levels after supplementation with 5 mg folic acid indicated that some pregnant women needed folate supplementation in preventing folic acid deficiency during pregnancy. A randomized controlled double-blind trial was undertaken in south Wales to prevent the recurrence of neural-tube defects in women who had had one child with a neural-tube defect. Sixty women were allocated before conception to take 4 mg of folic acid a day before and during early pregnancy and 44 complied with these instructions. Fifty-one women were allocated to placebo treatment. There were no recurrences among the compliant mothers but two among the non-compliers and four among the women in the placebo group. Thus there were no recurrences among those who received supplementation and six among those who did not; this difference is significant (p = 0.04). It is concluded that folic acid supplementation might be a cheap, safe, and effective method of primary prevention of neural-tube defects but that this must be confirmed in a large, multicentre trial. Fewer than one third of American women take folic acid daily, although many women report that they would take folic acid if their physicians advised them to do so. This study determined the impact of a physician intervention during routine gynecologic visits on folic acid supplementation.
                Patients were assigned randomly to receive brief folic acid counseling, a reminder phone call, and 30 folic acid tablets (n = 162 women; intervention group) or to receive counseling about other preventive health behaviors and a folic acid informational pamphlet (n = 160 women; control group). Self-reported folic acid use was compared at baseline and at 2 months.
                Of the 279 patients who completed the study, weekly folic acid intake increased in the intervention group by 68%, compared with 20% in the control group ( P =.008). No significant differences were found in daily intake. The women who were most influenced by the intervention were black and lower income and not planning pregnancies.
                With little effort expended to encourage folic acid use, gynecologists could potentially reduce the risk of folate-preventable birth defects among their patients by as much as 11%. In Korea, it is customary to prescribe iron and folic acid supplements to pregnant women after the 20th wk of gestation; however, little evidence exists to support this practice.
                The objective was to determine the effects of time of initiation and dose of prenatal iron and folic acid supplementation on the iron and folate nutriture of Korean women during pregnancy.
                A total of 131 pregnant women were placed into 1 of 5 experimental groups, either the control group or 1 of 4 supplemented groups. The supplemented groups varied by time of initiation, which was either during the first trimester or at week 20 of gestation, and by dose of iron and folic acid supplements provided, which consisted of either 30 mg Fe plus 175 microg folic acid or 60 mg Fe plus 350 microg folic acid. All supplemented groups continued supplementation until delivery.
                Improvements in iron and folate nutriture were highly dependent on when the supplement program was initiated, but both supplement doses were equally effective. In contrast, the influence of folic acid supplementation on maternal folate status was not as pronounced as was the influence of iron supplementation on iron status.
                In pregnant Korean women, initiating iron and folic acid supplementation earlier during pregnancy may prevent the deterioration of iron and folate nutriture more than does increasing supplement doses in later stages of pregnancy. A folic acid containing multivitamin preparation was evaluated for its efficacy in preventing recurrence of open neural tube defect (NTD) in a blind, placebo-controlled randomized trial. The trial was carried out at the five centres in India, viz., Bangalore, Mumbai, Lucknow, New Delhi and Pune.
                The preparation contained 4 mg of folic acid besides calcium, iron, zinc and vitamins A, B1, B2, B6, C, D and nicotinamide. The placebo contained calcium and iron only. A total of 466 women with previous history of giving birth to a child with open NTD were included in the trial (231 in the vitamin group and 235 in the placebo group). The supplementation was given for at least one month prior to conception and up to three months after conception. All women were offered antenatal diagnosis with screening of maternal serum alpha foetoprotein (AFP) and ultrasound.
                Pregnancy outcome with reference to recurrence of NTD was unknown in 137 women in the vitamin group and 142 in the placebo group. The recurrence of open NTD in the vitamin group was 2.92 per cent compared to 7.04 per cent in the placebo group, a reduction by about 60 per cent. The difference, however, was not statistically significant (P = 0.06).
                The study seems to support the role of periconceptional folic acid supplementation in prevention of recurrence of NTDs in the Indian population. The reason for high recurrence rate observed in the placebo group requires further investigation.
We found no conclusive evidence of benefit of folic acid supplementation during pregnancy on pregnancy outcomes.