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. Impact of micronutrient supplementation during pregnancy on birth weight, duration of gestation, and perinatal mortality in rural western China: double blind cluster randomised controlled trial. Effect of N-3 polyunsaturated fatty acid supplementation in pregnancy: the Nuheal trial. [Folic acid and pregnancy, a real problem?]. Iron supplementation studies among pregnant women. Pregnancy outcomes in a randomised controlled trial of periconceptional multivitamin supplementation. Final report. Folic acid and vitamin B12 supplementation during pregnancy in a population subsisting on a suboptimal diet. Folic acid supplement and intrauterine growth. EFFECT OF FOLIC ACID AND VITAMIN B12 SUPPLEMENTATION ON TESTS OF FOLATE AND VITAMIN B12 NUTRITION IN PREGNANCY. Folate supplements during pregnancy. Fortified mineral water improves folate status and decreases plasma homocysteine concentration in pregnant women. A prophylactic trial of iron and folic acid supplements in pregnant Burmese women. Comparison of effect of daily versus weekly iron supplementation during pregnancy on lipid peroxidation. A randomised, double-blind placebo-controlled trial of ascorbic acid supplementation for the prevention of preterm labour. Effects of topical and systemic folic acid supplementation on gingivitis in pregnancy.
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. To examine the impact of antenatal supplementation with multiple micronutrients or iron and folic acid compared with folic acid alone on birth weight, duration of gestation, and maternal haemoglobin concentration in the third trimester.
                Cluster randomised double blind controlled trial.
                Two rural counties in north west China.
                5828 pregnant women and 4697 live births.
                Villages were randomised for all pregnant women to take either daily folic acid (control), iron with folic acid, or multiple micronutrients with a recommended allowance of 15 vitamins and minerals.
                Birth weight, length, and head circumference measured within 72 hours after delivery. Neonatal survival assessed at the six week follow-up visit.
                Birth weight was 42 g (95% confidence interval 7 to 78 g) higher in the multiple micronutrients group compared with the folic acid group. Duration of gestation was 0.23 weeks (0.10 to 0.36 weeks) longer in the iron-folic acid group and 0.19 weeks (0.06 to 0.32 weeks) longer in the multiple micronutrients group. Iron-folic acid was associated with a significantly reduced risk of early preterm delivery (<34 weeks) (relative risk 0.50, 0.27 to 0.94, P=0.031). There was a significant increase in haemoglobin concentration in both iron-folic acid (5.0 g/l, 2.0 to 8.0 g/l, P=0.001) and multiple micronutrients (6.9 g/l, 4.1 to 9.6 g/l, P<0.001) groups compared with folic acid alone. In post hoc analyses there were no significant differences for perinatal mortality, but iron-folic acid was associated with a significantly reduced early neonatal mortality by 54% (relative risk 0.46, 0.21 to 0.98).
                In rural populations in China antenatal supplementation with iron-folic acid was associated with longer gestation and a reduction in early neonatal mortality compared with folic acid. Multiple micronutrients were associated with modestly increased birth weight compared with folic acid, but, despite this weight gain, there was no significant reduction in early neonatal mortality. Pregnant women in developing countries need sufficient doses of iron in nutrient supplements to maximise reductions in neonatal mortality. Trial registration ISRCTN08850194. In this placebo controlled, randomised, double blind trial, pregnant women received from the 20th week of gestation onwards either 500 mg docosahexaenoic acid (DHA), 400 mg 5-methyl-tetra-hydro-folate (5-MTHF), or placebo, or a combination of 500 mg DHA and 400 mg 5-MTHF. The dietary supplements were well tolerated; the dropout rates did not differ significantly in the active arms of the study (10% to 19%) from that seen in the placebo group (13%). DHA supplementation resulted in significant enhancement of the contribution of DHA to maternal, placental and venous cord blood lipids. The efficacy of prophylactic treatment with ferrous sulfate (80 mg Fe++) and the combination of ferrous sulfate with folic acid (80 mg Fe++ and 350 microgram folic acid) were studied in a double blind trial in the 20th, and again in the 30th and 36th week of pregnancy (29 patients). At the beginning of the treatment (20th week) 29% of the patients showed a pathologically reduced serum folic acid level. Combined therapy has a favorable effect on the folic acid levels in the serum and red blood cells; this was confirmed statistically. At the end of pregnancy, 69% of the patients of the control group (ferrous sulfate) showed a pathologically reduced serum level and 23% a subnormal level in erythrocytes. These results unquestionably justify the prophylactic prescription of folic acid during pregnancy. The effect of iron supplementation alone or in combination with ascorbic acid as a preventive and or corrective measure against anemia were tested using pregnant women seeking pre-natal consultation at various health centers in Greater Manila Area. One tablet containing 65 mg iron alone or in combination with ascorbic acid per day during a supplementation period which varied from 16.5 to 17.8 weeks maintained initial hemoglobin and hematocrit levels in non-anemic women. Three tablets of the same iron preparation (total of 195 mg iron) daily resulted in significant increases in hemoglobin and hematocrit in anemic women. Ascorbic acid had no apparent beneficial effect. Considering the positive response to iron treatment, it is recommended that a nationwide program of iron supplementation of pregnant Filipinos be undertaken. The effect of periconceptional multivitamin/trace element supplementation on pregnancy outcomes was evaluated in a randomised controlled trial. The final data-base included 5,502 females with confirmed pregnancy. A multivitamin including 0.8 mg folic acid or a trace element were supplemented for at least 28 days before conception and continuing for at least until the second missed menstrual period. Number of pregnancies, terminations of pregnancies, four types of fetal deaths, livebirths including low birth weight, preterm birth and sex ratio were analysed. Periconceptional multivitamin supplementation increased fertility (higher rates of cumulative conceptions and multiple births), had no significant effect on the rate of different groups of fetal deaths, low birth weight and preterm birth in singletons. This primary preventive method can reduce the occurrence and recurrence of neural-tube defects and had no other significant effect on pregnancy outcomes except multiple births. nan The effect of a folic acid supplment on birth weight and placental weight in women delivering in the early summer in Denmark was investigated. Thirty-six women with normal pregnancy and expected delivery in the first half of June were selected consecutively. They were paired two and two, and allotted to two groups, one of which was supplied daily with 5 mg folic acid, and the second with tablets without folic acid, from the 23rd week of pregnancy. A significant correlation was found between erythrocyte folic acid and birth weight. The infants in the folic acid group were 12.7 per cent heavier than those in the control group (p less than 0.01). A similar difference was found with regard to placental weight and the number of placental cells. nan In a controlled, prospective trial, the effects of giving ferrous sulphate 50 mg daily to 76 pregnant women was compared with giving ferrous sulphate 50 mg daily plus folic acid 0.5 mg daily to 82 women in 12 general practices in South-east England.No differences in obstetric complications were found between the two groups, although the evidence of some of the listed complications may be too rare for detection in a sample of patients of this size. There is no mandatory folic acid fortification of food in Finland. We investigated the effects of mineral water fortified with folic acid, vitamins B6, B12, D and calcium on serum and erythrocyte folate concentrations, serum vitamin B12 and plasma homocysteine concentrations in pregnancy.
                A randomized, controlled, double-blind, parallel-group intervention study.
                Seventy-four pregnant women were recruited from two health care units. The study began at the eleventh week with a two-week run-in period, followed by an eight-week intervention period. The diet was monitored by food records. During the intervention, subjects consumed 1000 mL/day fortified or normal mineral water. The pregnancies were monitored carefully.
                The folate intake was 255 microg/day in the study group and 274 microg/day in the controls. Serum folate concentrations increased in the study group by 10.3 nmol/L and decreased in the controls by 2.7 nmol/L (P<0.05) during the study. The erythrocyte folate concentrations increased in the study group by 360.9 nmol/L and in the controls by 195.6 nmol/L (P=0.004) and serum homocysteine concentrations fell by 1.1 micromol/L and by 0.3 micromol/L, respectively (P<0.05).
                Finnish pregnant women have low dietary folate intake. Fortified mineral water improved folate status and reduced plasma homocysteine concentrations in the pregnant subjects. Hemoglobin (Hb) concentration, serum iron level, iron binding capacity and blood folate (Lactobacillus casei) activity were determined in 310 unselected pregnant Burmese women. Hb concentration was less than 11 g/dl in 72% of the women; the serum iron level was less than 50 mug/dl in 33%; serum folate activity was less than 3ng/ml in 13%; and red cell folate activity was less than 100 ng/ml in 17% of the women. Ninety-six of the women in our study were randomly divided into four groups, treated from the 22nd to the 25th week of pregnancy until full term with either ferrous sulfate containing 60 mg elemental iron twice daily, 5 mg folic acid twice daily, a combination of both, or a placebo only. At full term, Hb concentration fell in the groups given placebo or folic acid. On the other hand, in the groups given iron alone or iron plus folic acid there was an increase in Hb of 0.4 and 0.7 g/dl, respectively (intergroup difference not statistically significant). Serum iron and blood folate levels fell in the groups not receiving the appropriate hematinic. In spite of deficient serum and red cell folate levels in 30 and 40%, respectively, of the group on iron alone, the mean Hb concentration increased at full term and none of the women had a Hb concentration lower than 10 g/dl. Blood folate levels were lower in the iron-supplemented group than in the placebo group, indicating that iron deficiency does not aggravate the folate nutritional status. To compare the effect of daily versus weekly iron supplementation on lipid peroxidation, hemoglobin levels and maternal and perinatal outcome in non-anemic pregnant women.
                Of 109 women randomly allocated into three groups, 90 completed the study. Group I (n = 30) received daily iron folic acid; Group II (n = 30) received weekly iron folic acid; Group III (n = 30) received daily iron (III)-hydroxide polymaltose complex. Hemoglobin levels, hematological indices, thiobarbituric acid reactive substances (TBARS) and glutathione levels were measured at baseline (14-16 weeks) and at 30-34 weeks. Statistical analysis was done using the anova test.
                Group I had a highly significant increase in TBARS level (0.61 +/- 0.26 micromol/L, P = 0.000) compared to groups II and III in which the change in TBARS was not significant (0.02 +/- 0.06 and 0.007 +/- 0.06 micromol/L, respectively). There was an insignificant fall in glutathione levels in all groups. There was no significant difference in the mean period of gestation, pregnancy complications and neonatal outcome between the three groups. Among 22.2% of women who were non-compliant, Group I had significantly higher incidence of non-compliance (P = 0.016) and side-effects (P = 0.001). Final hemoglobin was higher in Group I than II (11.9 +/- 1.2, 11.3 +/- 0.9, respectively, P = 0.041). The TBARS level was not statistically different between preterm and term deliveries. Nine out of 11 patients who developed hypertension during pregnancy had preeclampsia. The final TBARS level was significantly higher in these women (P = 0.000).
                Daily supplementation with ferrous sulphate results in greater lipid peroxidation than weekly supplementation, the latter is comparable with daily iron (III)-hydroxide polymaltose complex. Lipid peroxidation levels are significantly higher in preeclampsia. In a previous study from this institution, patients at high risk for preterm labour were screened for the presence of bacterial vaginosis (BV). When BV was present, they were randomised to receive either treatment (metronidazole) or placebo (vitamin C). There were significantly more patients with preterm labour in the metronidazole group. The aim of this double-blind randomised placebo-controlled trial study was to determine whether vitamin C could indeed reduce the recurrence risk of preterm labour. Patients with a history of preterm labour in a preceding pregnancy were randomised to receive 250 mg vitamin C or a matching placebo twice daily until 34 weeks' gestation. They attended a dedicated premature labour clinic. Significantly more women delivered before term in the group that received vitamin C, but there was no difference in the outcome of the babies between the two groups. Supplementation with vitamin C did not prevent premature labour. A double-blind study evaluated the effects of systemic and topical folate on gingival inflammation during the fourth and eighth months of pregnancy. Thirty women were randomly divided into three groups. Group A received placebo mouthwash and tablets; Group B; placebo mouthwash and 5 mg folate tablets; Group C: folate mouthwash and placebo tablets. Supplementation lasted for 14 days during months 4 and 8. Subjects took one tablet daily and rinsed twice daily for 1 min with the mouthwash. At the start and finish of each 14-day period, fasting serum and red cell folate levels were estimated and oral status assessed by a plaque index (P1I), a gingival index (GI), and gingival exudate flow meter (GEF). Subjects completed 1-week diet sheets which were analysed for dietary folate. All groups were similar in each parameter at the start. Correlation was demonstrated between GI and P1I, and between GI and GEF. GI tended to increase throughout pregnancy in all groups except Group C, when in the eighth month there was a highly significant improvement (0.001 less than P 0.01) despite no significant change in P1I. Although dietary intake of folate was significantly higher during the eighth month in Group C as compared with Groups A and B, (0.001 less than P less than 0.01), the folate mouthwash produced highly significantly improvement in gingival health in pregnancy.
We found no conclusive evidence of benefit of folic acid supplementation during pregnancy on pregnancy outcomes.