Folic Acid Supplementation During Early Pregnancy and the Risk of Gestational Hypertension and Preeclampsia

Maternal folic acid supplementation to prevent preeclampsia: a systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review was to examine the association between folic acid supplementation during pregnancy and the risk of preeclampsia.

METHODS

Relevant studies were included by searching Embase, PubMed, Scope, Web of science, Cochrane Library databases. Studies were reviewed according to prespecified inclusion and exclusion criteria. Study characteristics were summarized, and study quality was assessed. Risk ratios (RR) and 95% confidence intervals (CI) were used as indicators of effect to assess the relationship between folic acid supplementation and risk of preeclampsia.

RESULTS

The protocol of this study was prospectively registered with the PROSPERO (registration No. CRD42022380636). A total of nine studies were included, divided into three groups according to the type of study, containing a total of 107 051 and 105 222 women who were supplemented and not supplemented with folic acid during pregnancy. The results showed that folic acid supplementation during pregnancy could not be proven to reduce the risk of preeclampsia.

CONCLUSION

The results of the study suggest that folic acid supplementation alone is not associated with a decreased risk of pre-eclampsia,but the inferences are somewhat limited by the low methodological quality of the included literature, and therefore higher quality studies are needed to prove this point.

An association of deficiencies in balanced dietary practices and inadequate iron and folic acid supplement's intake during pregnancy and increasing risk of pre-eclampsia or eclampsia among Indian women

Pre-eclampsia or eclampsia is a serious reproductive health problem which can cause maternal, fetal and neonatal morbidity and mortality worldwide. However till the notable reasons of it is not very clear at all. The main essence of the present study was to examine the association between dietary intake, iron and folic acid consumption during pregnancy and the chances of occurrences of pre-eclampsia or eclampsia among Indian women. A cross sectional observational study was performed by using NFHS-5 (2019-21) data. 190,797 ever married women aged between 15-49 years who had a live birth in the past five years preceding the survey were availed for this study. Multivariable logistic regression analysis was carried out to find out the association between dietary and supplementary intake and occurrences of eclampsia. About 3.6% of the sample women had pre-eclampsia or eclampsia. The results of the study indicated that the likelihood of the prevalence of pre-eclampsia or eclampsia was significantly higher among those women who did not take adequate diet and as well as not consumed iron and folic acid tablet or syrup for at least 90 days during pregnancy compared to those women who took adequate diet and iron and folic acid supplementation even after controlling some maternal, health and lifestyle, socio-economic and demographic characteristics. Integrated and quality ANC services can only ensure adequate nutritional intake in terms of healthy and balanced diet. So, quality ANC services and with this micronutrients intake could be an effective way to reduce the prevalence of pre-eclampsia or eclampsia.

Folic acid: The key to a healthy pregnancy - A prospective study on fetomaternal outcome

Objectives

The objective of the study is to study the fetomaternal outcome associated with folic acid deficiency in pregnancy.

Materials and Methods

This hospital-based observational study was conducted in the Department of Obstetrics and Gynaecology at Base Hospital, Delhi Cantt, and a total of 351 participants were enrolled who were fulfilling the inclusion criteria. The plasma folic acid level of the selected patients was measured in the booking visit by automated chemiluminescence assay. The cutoff levels of folic acid were taken at 8.6 ng/mL. Based on these values, the study population was divided into two groups, one with folic acid values <8.6 ng/mL and the other with values ≥8.6 ng/mL. Plasma Vitamin B12 levels were measured to check for any concurrent deficiencies. Obstetric outcomes included first- and second-trimester miscarriages, development of anemia, gestational hypertension/preeclampsia, gestational diabetes mellitus, hypothyroidism, placental abruption, and intrauterine fetal growth restriction (FGR). Furthermore, the period of gestation at delivery, fetal weights, APGAR scores at 5 min were documented. The study also considered fetal neural tube defects, intrauterine fetal demise for data collection. Collected data were analyzed statistically to find the association of the above-mentioned outcomes with levels of folic acid.

Results

The rate of preterm deliveries was significantly higher in the folic acid group with levels <8.6 ng/mL (16.94%). The incidence of small for gestational age/FGR was higher in the folic acid group with levels <8.6 ng/mL (27.11%) compared to the high folic acid group with levels ≥8.6 ng/mL (13.38%). The differences in the incidence of anemia, gestational hypertension, gestational diabetes, and preeclampsia between the two groups were not statistically significant and no cases of intrauterine fetal demise or placental abruption were observed in either group. Moreover, there was no significant difference in the relative risk of low Apgar scores at 5 min between the two groups.

Conclusion

The present study suggests that low folic acid levels during pregnancy are associated with a higher risk of adverse pregnancy outcomes such as anemia, miscarriages, preterm delivery, and FGR. Therefore, adherence to nutritional recommendation of folic acid supplementation during pregnancy is essential to prevent these adverse outcomes.

Association of age at menarche with gestational hypertension and preeclampsia: A large prospective cohort in China

This study explored the potential association between age at menarche and the risks of gestational hypertension and preeclampsia in Chinese women. Data were sourced from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. Our study consisted of 209 411 women pre-registered for pregnancy in two provinces in South China. Trained healthcare workers measured blood pressure at registration and recorded other pertinent health information. Using logistic regression, we assessed the correlations between age at menarche and the likelihood of developing gestational hypertension and preeclampsia, considering confounders such as maternal age, body mass index, ethnicity, parity, folic acid supplementation, education level, and occupation. The observed incidences for gestational hypertension and preeclampsia were 9.65% and 2.54%, respectively. The adjusted odds ratios (ORs) for gestational hypertension, based on age at menarche, were as follows: ≤13 years, 1.18 (95% confidence interval: 1.11-1.26); 14 years, 1.09 (1.04-1.15); 15 years, 1.11 (1.06-1.16); 16 years, 1.06 (1.01-1.12); and ≥17 years, 1.00 (reference; P for trend < .001). The correlation between age at menarche and preeclampsia varied across age groups, with the following respective ORs: 1.35 (1.20-1.52), 1.21 (1.09-1.34), 1.27 (1.15-1.39), 1.14 (1.03-1.26), and 1.00 (reference; P for trend < .001). This association appeared to be more pronounced in women with no folic acid supplementation and those with a lower education level. In conclusion, an earlier age at menarche seems to be linked to increased risks of gestational hypertension and preeclampsia.

Folate, vitamin B6, and vitamin B12 intakes are negatively associated with the prevalence of hypertension: A national population-based study

We hypothesized that the prevalence of hypertension is related to B-vitamin intake in the general population, but it has not been sufficiently studied. This study aimed to investigate the intakes of dietary folate, vitamin B₆, and vitamin B₁₂ concerning hypertension in US adults. A total of 55 569 adults from National Health and Nutrition Examination Survey III and 1999-2014 were included in this study. Nutrient intake was collected from subjects through one or two 24-hour dietary reviews. Multiple logistic regression models were used to examine the relationship between these nutrient intakes and hypertension. Among male participants, dietary folate, vitamin B₆, and vitamin B₁₂ intakes were significantly and negatively associated with the prevalence of hypertension, with multivariate-adjusted odds ratios (ORs) of 0.61 (95% confidence interval [CI], 0.55-0.68), 0.65 (95% CI, 0.59-0.72), and 0.84 (95% CI, 0.75-0.95) for the highest quartile group compared with the lowest group. Results were similar for female participants, with multivariate-adjusted ORs of 0.63 (95% CI, 0.57-0.71), 0.60 (95% CI, 0.53-0.66), and 0.87 (95% CI, 0.77-0.98) for the highest quartile group. Moreover, there was a linear trend (P_trend < .001) in both men and women that the prevalence of hypertension tended to decrease with increased intake of folate, vitamin B₆, and vitamin B₁₂; however, the decreases above the third quartile were negligible. Dietary folate, vitamin B₆, and vitamin B₁₂ were significantly associated negatively with hypertension, indicating that these nutrients might have a protective effect against hypertension in United States adults.

Health-Promoting Ingredients in Goat's Milk and Fermented Goat's Milk Drinks

The present study aimed to determine the content of health-promoting compounds, and fatty acids, with particular emphasis on the content of cis9trans11 C18:2 (CLA) acid, selected minerals, folates in organic and commercial goat's milk and fermented goat's milk drinks. The analyzed milk and yoghurts had various contents of particular groups of fatty acids, CLA, minerals, and folates. Raw organic goat's milk had a significantly (p < 0.05) higher content of CLA (3.26 mg/g fat) compared to commercial milk (2.88 mg/g fat and 2.54 mg/g fat). Among the analyzed fermented goat's milk drinks, the highest CLA content (4.39 mg/g fat) was determined in commercial natural yoghurts, while the lowest one was in organic natural yoghurts (3.28 mg/g fat). The highest levels of calcium (1322.9-2324.4 µg/g), phosphorus (8148.1-11,309.9 µg/g), and copper (0.072-0.104 µg/g) were found in all commercial products and those of manganese (0.067-0.209 µg/g) in organic products. The contents of the other assayed elements (magnesium, sodium, potassium, iron, and zinc) did not depend on the production method, but only on the product type, i.e., the degree of goat's milk processing. The highest folate content in the analyzed milks was found in the organic sample (3.16 µg/100 g). Organic Greek yoghurts had a several times higher content of folates, reaching 9.18 µg/100 g, compared to the other analyzed fermented products.

Biological Role of Folic Acid in Pregnancy and Possible Therapeutic Application for the Prevention of Preeclampsia

The rationale and importance of folic acid supplementation during pregnancy for fetal congenital defect prevention are accepted worldwide. Moreover, a sufficient plasma concentration of folates can reduce the incidence of spontaneous abortions, and support the normal expansion of placental blood vessels, ensuring physiological placental blood flow, thus promoting appropriate fetal growth and development. Furthermore, there is emerging evidence that long-term supplementation with folic acid can effectively prevent preeclampsia. Preeclampsia is unique to the human species in complications during pregnancy, which contributes to maternal and perinatal mortality worldwide. In the pathogenesis of preeclampsia abnormal placental invasion, the excess of antiangiogenic factors and maternal-placental syndrome play a key role. Increased blood levels of homocysteine during pregnancy are associated with the risk of preeclampsia. Moreover, hyperhomocysteinemia has been proposed to be an independent risk factor for preeclampsia. Folate supplementation helps to decrease elevated levels of homocysteine; thus, the role of folic acid supplementation in pregnancy is even more important. Multiple reports suggest that folate administration decreases the level of serum homocysteine and, therefore, reduce the risk and severity of preeclampsia. However, the association between folic acid supplementation and the decreased risk of preeclampsia has been investigated with controversial conclusions. Currently, the optimal dose of folic acid that is effective for preeclampsia prevention remains uncertain. In this review, we aim to summarize the accumulated knowledge on the role of folic acid in the pathogenesis of preeclampsia, and the possible impact of folate supplementation on the decreased risk of preeclampsia.

Health-Promoting Nutrients and Potential Bioaccessibility of Breads Enriched with Fresh Kale and Spinach

Bread is a staple food and can be a potential product to be enriched with various deficient nutrients. The objective of the study was to characterize the nutritional properties of toasted bread enriched with 10% and 20% of kale and wholemeal bread with 20% and 40% of spinach. The supplementation increased the phenolic content up to 2−3 times in the bread with the addition of 20% spinach and 40% kale. The highest antioxidant properties were noticed in extracts of bread with 20% kale. The in vitro digestion released the hydrophilic and lipophilic antioxidative compounds, leading to higher bioaccessibility of the breads enriched with these selected green vegetables. Even more than a 2-fold increase in folate content was observed in breads with the greatest addition of kale (20%) and spinach (40%), from 18.1 to 45.3 µg/100 g and from 37.2 to 83.2 µg/100 g, respectively, compared to the non-enriched breads. Breads with spinach showed significantly (P < 0.05) higher contents of all of the tested minerals, Cu, Mn, Fe, Zn, Mg, Ca, Na, K, and P, whereas kale enriched breads showed most of them. The results suggest that the addition of fresh green vegetables can enhance the daily supply of micronutrients and significantly increase the bioavailability of bioactive compounds with high antioxidant status.

Impact of gestational hypertension and pre-eclampsia on preterm birth in China: a large prospective cohort study

OBJECTIVE

To investigate the impact of gestational hypertension and pre-eclampsia on preterm birth.

DESIGN

The data were collected from the China-US Collaborative Project for Neural Tube Defect Prevention; this was a large population-based cohort study.

SETTING AND PARTICIPANTS

We selected participants registered in two southern provinces, for whom we had exact information on gestational blood pressure and pregnancy outcomes, and who were not affected by chronic hypertension. In total, 200 103 participants were recruited from 1993 to 1995.

OUTCOME MEASURES

Preterm birth was defined as a singleton pregnancy and birth before 37 gestational weeks.

RESULTS

The incidences of gestational hypertension and pre-eclampsia were 5.47% and 5.44%, respectively, for women who gave birth at full term, and 5.63% and 7.33%, respectively, for those who gave birth preterm. After adjusting for potential confounders, the risk ratios (RRs) of preterm birth in women with gestational hypertension and pre-eclampsia were 1.04 (95% CI 0.98 to 1.11) and 1.39 (95% CI 1.25 to 1.55), respectively. The associations were stronger for early-onset (<28 weeks of gestation) gestational hypertension (adjusted RR=2.13, 95% CI 1.71 to 2.65) and pre-eclampsia (adjusted RR=8.47, 95% CI 5.59 to 12.80).

CONCLUSIONS

Pre-eclampsia was associated with a higher risk of preterm birth. The early-onset gestational hypertension and pre-eclampsia were associated with more severe risks than late-onset conditions.

Association between Folic Acid Supplementation and Hypertensive Disorder Complicating Pregnancy in Jiangsu Province: A Cross-Sectional Study

Objectives

To investigate the association of folic acid (FA) supplementation with hypertensive disorder complicating pregnancy (HDCP) and preeclampsia in Jiangsu Province, China.

Materials and Methods

In this cross-sectional study, a total of 10,662 women with infants born between January 2017 and December 2018 were enrolled in Jiangsu Province, China. Maternal women with and without FA supplement intake were compared in this study. FA supplementation included 0.4 mg FA (0.4 FA), multivitamins with 0.4 mg FA (multivitamin (MV)+0.4 FA), and multivitamins with 0.8 mg FA (MV + 0.8 FA). Associations between FA intake, FA supplement dose or duration, (MV + FA) dosage per weight, and HDCP were analysed using ANOVA, the chi-square test, and logistic regression analysis.

Results

Over the study follow-up period, the incidences of HDCP and preeclampsia were 3.5%, 1.4%, and 2.2%, 0.6% in the non-FA supplementation and FA supplementation groups, but only 1.5% and 0.1% in the MV + 0.8 FA group in early pregnancy. Compared with the non-FA group, HDCP and preeclampsia had the lowest risk in the MV + 0.8 FA group among the seven FA supplementation groups (HDCP: RR = 0.42, 95% CI = 0.27-0.68, P=0.001; preeclampsia: RR = 0.09, 95% CI = 0.03–0.33, P=0.001) in early pregnancy. Compared with the 0.4 FA alone group, the risk of HDCP and preeclampsia in women taking MV + 0.8 FA was significantly reduced (RR = 0.60, 95% CI = 0.41–0.87, P=0.008; preeclampsia: RR = 0.18, 95% CI = 0.06–0.60, P=0.005) in early pregnancy. (MV + FA)/BMI supplementation was associated with the risk of HDCP in early pregnancy (P trend = 0.002).

Conclusions

MV supplement with 0.8 mg FA during early pregnancy may be effective in reducing HDCP and preeclampsia risk. The study provided the viewpoint that (MV + FA)/BMI could be used as a reference for FA intake in pregnant women of different weights.

Characteristics of Dietary Supplements with Folic Acid Available on the Polish Market

One way of increasing folate status, especially in a state of increased demand (e.g., women of childbearing age), is dietary supplementation with folic acid (FA). The dietary supplements market in Poland shows a controversial situation and, for many reasons (the ease of placing them on the market, the lack of control of chemical composition), the possibility of inaccurate information provided on the supplement’s label arises. We questioned whether FA supplements available in Poland are indeed complying with regulations and if they could actually improve folate status amongst the target population groups consuming them. Almost 500 products containing FA were identified and available for sale in pharmacies, all of them including specific information provided by manufacturers on the packaging, such as the amount of FA, their intended use and daily dosage. HPLC analysis of FA content in 30 randomly purchased supplements exposed that in four of the tested products, FA content was less than 4% of the declared value (DV). Another 11 samples exposed that the difference with declared FA content varied from 25% up to 80% of the DV. The obtained results are in agreement with the ones from inspections previously conducted on the Polish dietary supplements market and indicate the urgent need to implement improvements in the notification system as well as the monitorization of these product’s authenticity.

Folic acid supplementation in pregnant women with hepatitis B surface antigen improves infant hepatitis B surface antibody mediated by infant IL-4

Immunoprophylaxis has not completely eliminated hepatitis B virus (HBV) infection due to hyporesponsiveness to hepatitis B vaccine (HepB). We explored the impact of folic acid supplementation (FAS) in pregnant women with positive hepatitis B surface antigen (HBsAg) on their infant hepatitis B surface antibody (anti-HBs) and the mediation effect of infant interleukin-4 (IL-4). We recruited HBsAg-positive mothers and their neonates at baseline. Maternal FAS was obtained via a questionnaire, and neonatal anti-HBs and IL-4 were detected. Follow-up was performed at 11-13 months of age of infants, when anti-HBs and IL-4 were measured. We applied univariate and multivariate analyses. A mediation effect model was performed to explore the mediating role of IL-4. A total of 399 mother-neonate pairs were enrolled and 195 mother-infant pairs were eligible for this analysis. The infant anti-HBs geometric mean concentrations in the maternal FAS group were significnatly higher than those in the no-FAS group (383·8 mIU/ml, 95 % CI: 294·2 mIU/ml to 500·7 mIU/ml v. 217·0 mIU/ml, 95 % CI: 147·0 mIU/ml to 320·4 mIU/ml, z = -3·2, P = 0·001). Infants born to women who took folic acid (FA) within the first trimester were more likely to have high anti-HBs titres (adjusted β-value = 194·1, P = 0·003). The fold change in IL-4 from neonates to infants partially mediated the beneficial influence of maternal FAS on infant anti-HBs (24·7 % mediation effect) after adjusting for confounding factors. FAS during the first trimester to HBsAg-positive mothers could facilitate higher anti-HBs levels in infants aged 11-13 months partly by upregulating IL-4 in infants.

Continuous supplementation of folic acid in pregnancy and the risk of perinatal depression-A meta-analysis

BACKGROUND

The blood folic acid¹(FA) level of depressed patients seems to be lower than that of normal, and pregnant women are at greater risk of FA deficiency. The relationship between FA and perinatal depression has not been well described.

METHODS

We conducted a meta-analysis of the evidence for the association between the two, using current FA supplementation behavior during pregnancy and blood FA levels as exposures, and the incidence of perinatal depressive symptoms and mean Edinburgh Postnatal Depression Scale² (EPDS) scores as outcomes. The present study was recorded in PROSPERO (2019 CRD: 42,020,211,509).

RESULTS

Fifteen studies were identified, covering a total of 26,275 women from eleven observational studies and four randomized controlled trials. For the primary outcome of folic acid supplementation behavior and risk of perinatal depression, the overall odds ratio was 0.742 (95% CI: (0.647-0.852)), with a combined effect value of 0.84 (95% CI: (0.76, 0.93)) for studies in which an OR could be extracted. A negative association was observed between blood folate levels and depressive symptoms (Standardized mean difference (SMD) =-0.127, 95% CI:(-0.183,-0.071)). No association was observed between folic acid intervention and EPDS score. Continuous supplementation of folic acid during pregnancy may reduce the incidence of perinatal depressive symptoms (R = 0.017, (95 CI%:(0.014, 0.021)).

LIMITATIONS

Lack of rigorous randomized controlled trials due to ethical issues, and the research is heterogeneous and does not consider the influence of genetic factors.

CONCLUSIONS

Continuous use of FA during pregnancy may reduce the incidence of perinatal depressive symptoms.

Effects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review

Background

Almost two billion people who are deficient in vitamins and minerals are women and children in low- and middle-income countries (LMIC). These deficiencies are worsened during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child. To reduce micronutrient deficiencies, several strategies have been implemented, including diet diversification, large-scale and targeted fortification, staple crop bio-fortification and micronutrient supplementation.

Objectives

To evaluate and summarize the available evidence on the effects of micronutrient supplementation during pregnancy in LMIC on maternal, fetal, child health and child development outcomes. This review will assess the impact of single micronutrient supplementation (calcium, vitamin A, iron, vitamin D, iodine, zinc, vitamin B12), iron-folic acid (IFA) supplementation, multiple micronutrient (MMN) supplementation, and lipid-based nutrient supplementation (LNS) during pregnancy.

Search Methods

We searched papers published from 1995 to 31 October 2019 (related programmes and good quality studies pre-1995 were limited) in CAB Abstracts, CINAHL, Cochrane Central Register of Controlled Trials, Embase, International Initiative for Impact Evaluations, LILACS, Medline, POPLINE, Web of Science, WHOLIS, ProQuest Dissertations & Theses Global, R4D, WHO International Clinical Trials Registry Platform. Non-indexed grey literature searches were conducted using Google, Google Scholar, and web pages of key international nutrition agencies.

Selection Criteria

We included randomized controlled trials (individual and cluster-randomized) and quasi-experimental studies that evaluated micronutrient supplementation in healthy, pregnant women of any age and parity living in a LMIC. LMIC were defined by the World Bank Group at the time of the search for this review. While the aim was to include healthy pregnant women, it is likely that these populations had one or more micronutrient deficiencies at baseline; women were not excluded on this basis.

Data Collection and Analysis

Two authors independently assessed studies for inclusion and risk of bias, and conducted data extraction. Data were matched to check for accuracy. Quality of evidence was assessed using the GRADE approach.

Main Results

A total of 314 papers across 72 studies (451,723 women) were eligible for inclusion, of which 64 studies (439,649 women) contributed to meta-analyses. Seven studies assessed iron-folic acid (IFA) supplementation versus folic acid; 34 studies assessed MMN vs. IFA; 4 studies assessed LNS vs. MMN; 13 evaluated iron; 13 assessed zinc; 9 evaluated vitamin A; 11 assessed vitamin D; and 6 assessed calcium. Several studies were eligible for inclusion in multiple types of supplementation. IFA compared to folic acid showed a large and significant (48%) reduction in the risk of maternal anaemia (average risk ratio (RR) 0.52, 95% CI 0.41 to 0.66; studies = 5; participants = 15,540; moderate-quality evidence). As well, IFA supplementation demonstrated a smaller but significant, 12% reduction in risk of low birthweight (LBW) babies (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). MMN supplementation was defined as any supplement that contained at least 3 micronutrients. Post-hoc analyses were conducted, where possible, comparing the differences in effect of MMN with 4+ components and MMN with 3 or 4 components. When compared to iron with or without FA, MMN supplementation reduced the risk of LBW by 15% (average RR 0.85, 95% CI 0.77 to 0.93; studies = 28; participants = 79,972); this effect was greater in MMN with >4 micronutrients (average RR 0.79, 95% CI 0.71 to 0.88; studies = 19; participants = 68,138 versus average RR 1.01, 95% CI 0.92 to 1.11; studies = 9; participants = 11,834). There was a small and significant reduction in the risk of stillbirths (average RR 0.91; 95% CI 0.86 to 0.98; studies = 22; participants = 96,772) and a small and significant effect on the risk of small-for-gestational age (SGA) (average RR 0.93; 95% CI 0.88 to 0.98; studies = 19; participants = 52,965). For stillbirths and SGA, the effects were greater among those provided MMN with 4+ micronutrients. Children whose mothers had been supplemented with MMN, compared to IFA, demonstrated a 16% reduced risk of diarrhea (average RR 0.84; 95% CI 0.76 to 0.92; studies = 4; participants = 3,142). LNS supplementation, compared to MMN, made no difference to any outcome; however, the evidence is limited. Iron supplementation, when compared to no iron or placebo, showed a large and significant effect on maternal anaemia, a reduction of 47% (average RR 0.53, 95% CI 0.43 to 0.65; studies = 6; participants = 15,737; moderate-quality evidence) and a small and significant effect on LBW (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). Zinc and vitamin A supplementation, each both compared to placebo, had no impact on any outcome examined with the exception of potentially improving serum/plasma zinc (mean difference (MD) 0.43 umol/L; 95% CI -0.04 to 0.89; studies = 5; participants = 1,202) and serum/plasma retinol (MD 0.13 umol/L; 95% CI -0.03 to 0.30; studies = 6; participants = 1,654), respectively. When compared to placebo, vitamin D supplementation may have reduced the risk of preterm births (average RR 0.64; 95% CI 0.40 to 1.04; studies = 7; participants = 1,262), though the upper CI just crosses the line of no effect. Similarly, calcium supplementation versus placebo may have improved rates of pre-eclampsia/eclampsia (average RR 0.45; 95% CI 0.19 to 1.06; studies = 4; participants = 9,616), though the upper CI just crosses 1.

Authors' Conclusions

The findings suggest that MMN and vitamin supplementation improve maternal and child health outcomes, including maternal anaemia, LBW, preterm birth, SGA, stillbirths, micronutrient deficiencies, and morbidities, including pre-eclampsia/eclampsia and diarrhea among children. MMN supplementation demonstrated a beneficial impact on the most number of outcomes. In addition, MMN with >4 micronutrients appeared to be more impactful than MMN with only 3 or 4 micronutrients included in the tablet. Very few studies conducted longitudinal analysis on longer-term health outcomes for the child, such as anthropometric measures and developmental outcomes; this may be an important area for future research. This review may provide some basis to guide continual discourse around replacing IFA supplementation with MMN along with the use of single micronutrient supplementation programs for specific outcomes.

Effects of prenatal micronutrients supplementation timing on pregnancy-induced hypertension: Secondary analysis of a double-blind randomized controlled trial

In this secondary analysis of data from a double‐blind randomized controlled trial (clinicaltrials.gov identifier: NCT00133744) of micronutrient supplementation (multiple micronutrients [MMN], iron–folic acid [IFA] and folic acid [FA] alone), we examined the potential modifying effect of gestational age at enrolment on the association of antenatal supplementation and pregnancy‐induced hypertension (PIH). We included 18,775 nulliparous pregnant women with mild or no anaemia who were enrolled at 20 weeks of gestation or earlier from five counties of northern China. Women were randomly assigned to receive daily FA, IFA or MMN from enrolment until delivery. We used logistic regression to evaluate the association between PIH and timing of micronutrient supplementation. The incidence of PIH was statistically significantly lower among women who began MMN supplementation before 12 gestational weeks compared with women who began MMN supplementation at 12 weeks or later (RR = 0.74, 95% CI: 0.60–0.91). A similar protective effect was observed for both early‐onset (<28 weeks, RR 0.45, 0.21–0.96) and late‐onset of PIH (≥28 weeks, RR 0.77, 0.63–0.96). No statistically significant association was observed between PIH occurrence and timing of supplementation for FA or IFA. Maternal MMN supplementation and antenatal enrolment during the first trimester of pregnancy appeared to be of importance in preventing both early‐ and late‐onset of PIH.

Impact of gestational hypertension and preeclampsia on low birthweight and small-for-gestational-age infants in China: A large prospective cohort study

Studies have shown that maternal blood pressure level is associated with neonatal birthweight, but the results are not exactly consistent. As the most common hypertensive disorders during pregnancy, the mechanism of gestational hypertension and pre‐eclampsia that affect fetal growth remain unclear. Our objective was to examine the association of gestational hypertension and pre‐eclampsia with the risk of low birthweight (LBW) and small‐for‐gestational‐age (SGA). Data were obtained from the China–US Collaborative Project for Neural Tube Defects Prevention, a large population‐based cohort study. We selected participants who were registered in two southern provinces, had exact information on gestational blood pressure and pregnancy outcomes, and were not affected by chronic hypertension. Logistic regression was used to adjust for the effects of the main potential confounders, including age, body mass index, education, occupation, ethnicity, folic acid use, and parity. The overall incidences of LBW and SGA were 2.25% and 5.86%, respectively. The incidences of LBW/SGA were 3.58%/7.58% and 6.02%/10.67% for gestational hypertension and pre‐eclampsia group, relative to 2.11%/5.68% and 2.16%/5.74% for normal group. The adjusted odds ratios associated with gestational hypertension/pre‐eclampsia were 1.77 (95% CI: 1.63, 1.92)/3.01 (95% CI: 2.67, 3.40) for LBW and 1.40 (95% CI: 1.32, 1.48)/2.02 (95% CI: 1.84, 2.22) for SGA, respectively. The early onset of gestational hypertension/pre‐eclampsia appeared to be a relatively more detrimental exposure window for both LBW and SGA. Our results support an association between gestational hypertension or pre‐eclampsia and the increased risk of LBW and SGA.

Increased Uric Acid, Gamma-Glutamyl Transpeptidase and Alkaline Phosphatase in Early-Pregnancy Associated With the Development of Gestational Hypertension and Preeclampsia

Background: Previous studies have reported that biomarkers of liver injury and renal dysfunction were associated with hypertensive disorders of pregnancy (HDP). However, the associations of these biomarkers in early pregnancy with the risk of HDP and longitudinal blood pressure pattern during pregnancy were rarely investigated in prospective cohort studies. Methods: A total of 1,041 pregnant women were enrolled in this prospective cohort study. BP was assessed in four stages throughout pregnancy. The following biomarkers were measured at early pregnancy before 18 weeks gestation: lactate dehydrogenase (LDH), aspartate aminotransferase to alanine aminotransferase ratio (AST/ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), uric acid (UA), and estimated glomerular filtration rate (eGFR). Linear mixed-effects and logistic regression models were used to examine the associations of these biomarkers with longitudinal BP pattern during pregnancy and HDP incidence, respectively. Results: In unadjusted models, higher serum UA, GGT, ALP, and LDH levels, as well as lower eGFR and AST/ALT, were associated with higher BP levels during pregnancy and an increased risk of HDP. After adjustment for maternal age, pre-pregnancy BMI and other potential confounders, UA, GGT, ALP, and LDH remained positively associated with both BP and HDP. However, eGFR and AST/ALT were not associated with HDP after adjusting for potential confounders. When including all 6 biomarkers simultaneously in multivariable analyses, increased UA, GGT, and ALP significantly associated with gestational hypertension and preeclampsia. Conclusion: This study suggests that increased UA, GGT, and ALP in early-pregnancy are independent risk factors of gestational hypertension and preeclampsia.

Knowledge and awareness of folic acid usage in Saudi pregnant women in Riyadh city from 2019-2020

BACKGROUND

Folic acid (FA) supplementation is an important intervention to avoid nutritional deficiencies during pregnancy and later on will have an effect on mother and fetus. Inadequate dietary intake will lead to nutritional deficiency which further requires to depend on supplementation. FA is one of the vital nutrients which is mandatory for improving pregnancy outcomes. Previous studies have documented the pregnant women who know about supplementation of FA but not consuming during pregnancy will lead to complications in their neonates. This study aimed to inspect the knowledge and awareness about supplementation of FA in Saudi pregnant women and to compare present study results with other prior studies carried out in the Saudi population.

METHODS

In this study, we have opted 406 Saudi pregnant women with the age range of 18-65 years of age through questionnaire-based research, was further assessed for FA supplementation usage during the pregnancy. Involved pregnant women have filled questionnaire and signed the consent form.

RESULTS

The results of this study showed 38% of women were pregnant during 31-40 years of the age range. Almost 96% of pregnant women have awareness about FA supplementation during pregnancies, and 5.9% of women had histories for not using FA supplementation and had abnormal offspring. The current study questionnaire survey confirms 55.7% of pregnant women have information about FA supplementations. Nearly 89% of women have used FA in their previous pregnancies.

CONCLUSION

Saudi pregnant women has good knowledge and awareness about the usage of FA supplementation during pregnancy. Limited efforts should be implemented national wide in all the hospitals and clinics to improve the awareness about maternal nutrition during pregnancy. Nutritional counselling should be conducted in remote areas to get a perception in Saudi Arabia.

Epigenetic Modification in Methylene Tetrahydrofolate Reductase (MTHFR) Gene of Women with Pre-eclampsia

Background

Genetic and epigenetic factors play significant roles in the aetio-pathogenesis of pre-eclampsia (PE). The effects may vary across racial and geographical boundaries. The role of epigenetic modification in pre-eclampsia was studied among African populations in Lagos, Nigeria.

Aim and Objectives

This study aimed to determine the pattern of Methylene tetrahydrofolate reductase gene (MTHFR) CpG island methylation in pre-eclampsia, and evaluate associated covariates.

Methodology

This study was an observational, cross-sectional, study conducted at the Lagos University Teaching Hospital and the Lagos State Island Maternity Hospital. A total of 400 pregnant women consisting of 200 pregnant women diagnosed with pre-eclampsia (study group) and 200 pregnant normotensive and apparently healthy women (control group) were recruited for the study. Demographic and clinical histories were obtained through questionnaires. The DNA Methylation status of the CpG Island in promoter region of the MTHFR gene was assessed using bisulphite conversion and methylation specific PCR method. The biochemical parameters measured in the study were: red cell folate, vitamin B12, plasma homocysteine (Hcy) and methylene tetrahydrofolate reductase enzyme level.

Results

Homozygous MTHFR CpG island hypomethylation pattern was significantly associated with pre-eclampsia (χ ² = 22.96; p = 0.000), Mean values of plasma homocysteine in PE women with homozygous hypomethylation (26.1 ± 9.1 umol/L) were significantly higher than (20.1 ± 4.2 umol/L) observed in PE subjects with homozygous hypermethylation (p = 0.008). Homozygous CpG island hypomethylated pattern of the MTHFR promoter region, was associated with the lowest median MTHFR enzyme level (72.8 ± 39.8 pmol/L) compared with heterozygous methylated pattern (91.3 ± 60.9 pmol/L; p = 0.047) and homozygous methylated pattern (82.3 ± 31.0 pmol/L; 0.047). Red cell folate and Vitamin B12 levels were not significantly associated with CpG island methylation status.

Conclusion

Epigenetic modification plays significant role in the pathogenesis of pre-eclampsia.

Folic Acid Supplement Use and Increased Risk of Gestational Hypertension

Current results regarding the effect of folic acid (FA) supplement use on gestational hypertension (GH) and preeclampsia are limited and inconsistent. We aimed to investigate whether FA supplement use was associated with GH and preeclampsia. Participants from the Tongji Maternal and Child Health Cohort with information on periconceptional FA supplement use and diagnosis of GH/preeclampsia were included (n=4853). Robust Poisson regression was used to assess the association of FA supplement use and GH and preeclampsia. Among the 4853 participants in this study, 1161 (23.9%) and 161 (3.3%) women were diagnosed with GH and preeclampsia, respectively. The risk ratio of developing GH was higher in women who used ≥800 µg/d FA supplement from prepregnancy through midpregnancy than nonusers (risk ratio, 1.33 [1.08–1.65]). After adjusting for social-demographic, reproductive, lifestyle factors, family history of hypertension, other supplement use, and gestational weight gain, the adverse association remained significant (risk ratio, 1.32 [1.06–1.64]). Restricting the analysis among women with normal weight, without family history of hypertension, and without gestational diabetes mellitus, the positive FA-GH association still existed. We did not find any significant association between FA supplement use and preeclampsia regardless of adjustment. High-dose (≥800 µg/d) FA supplement use from prepregnancy through midpregnancy was associated with increased risk of GH. Attention should be given to avoid the potential risk of GH due to inappropriate FA supplement use in women who are planning or capable of pregnancy.

Preconception blood pressure and risk of gestational hypertension and preeclampsia: a large cohort study in China

Our objective was to examine whether high blood pressure in the preconception period was associated with gestational hypertension and preeclampsia in Chinese women. Data were obtained from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. We included 45,628 women who were registered before pregnancy in seven counties in South China. Blood pressure was measured during registration by trained health care workers, and other health-related information was recorded prospectively. We used logistic regression to evaluate the associations between preconception blood pressure and the risk of gestational hypertension and preeclampsia, adjusting for potential confounders. The prevalence of hypertension in the preconception study population was 4.57% (2083/45,628). The incidences of gestational hypertension and preeclampsia were 11.95% and 4.08%, respectively, in the hypertension group and 8.60% and 2.28%, respectively, in the nonhypertension group. Compared with the nonhypertension group, the hypertension group showed a significantly increased risk for gestational hypertension [adjusted risk ratio (RR) = 1.40, 95% confidence interval (CI): 1.22-1.60] and preeclampsia [adjusted RR = 1.75, 95% CI: 1.39-2.19]. When participants with normal blood pressure were used as the reference, the adjusted ORs for gestational hypertension were 1.48 (95% CI: 1.37-1.59), 1.70 (95% CI: 1.44-2.01), and 1.29 (95% CI: 1.02-1.64), and for preeclampsia, the adjusted ORs were 1.55 (95% CI: 1.35-1.78), 1.95 (95% CI: 1.46-2.60), and 1.99 (95% CI: 1.39-2.85) for the participants with prehypertension, stage 1 hypertension, and stage 2 hypertension, respectively. Our results support an association between hypertension or higher blood pressure prior to pregnancy and an increased risk of gestational hypertension and preeclampsia.

Reference ranges and trajectories for blood pressure in pregnancy: findings from a follow-up study based on China Maternal and Newborn's Health Monitoring System

Objectives: This study aimed to establish normal blood pressure reference ranges across gestation and maternal characteristics.Methods: We conducted a follow-up study including 29,200 Chinese normal pregnant women. Multilevel restrictive cubic spline models were used to calculate normal blood pressure reference ranges among all population and stratified groups.Results: In all normal pregnancies, the normal reference range of systolic blood pressure were 93.94-118.74 mmHg(2.5^th-97.5^th) and 97.35-124.63 mmHg at 12 and 37 weeks gestation, respectively while 58.79-74.21 mmHg and 59.19-78.25 mmHg were for diastolic blood pressure at 12 and 37 weeks gestation, which differed in subgroups stratified by prepregnancy body mass index and maternal age.Conclusion: This study provides evidence for blood pressure management in Chinese pregnant women.

Evidence of a Role for One-Carbon Metabolism in Blood Pressure: Can B Vitamin Intervention Address the Genetic Risk of Hypertension Owing to a Common Folate Polymorphism?

Hypertension in adulthood is recognized as the leading risk factor contributing to mortality worldwide, primarily from cardiovascular disease, whereas hypertension in pregnancy leads to serious adverse fetal and maternal outcomes. This article explores the under-recognized role of one-carbon metabolism in blood pressure (BP) and the potential for folate-related B vitamins to protect against hypertension. Genome-wide association studies and clinical studies provide evidence linking the 677C→T polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR) with BP and increased risk of hypertension and hypertension in pregnancy. A novel role for riboflavin (the MTHFR cofactor) has recently emerged, however, with evidence from randomized trials that supplemental riboflavin can lower BP specifically in adults with the variant MTHFR 677TT genotype. Further studies are required to elucidate the biological mechanisms linking one-carbon metabolism with BP and explore the effect of riboflavin in modulating the genetic risk of hypertension in early and later life.

Gestational hypertension and pre-eclampsia and risk of spontaneous premature rupture of membranes: A population-based cohort study

OBJECTIVE

To examine whether gestational hypertension and pre-eclampsia are associated with spontaneous premature rupture of membranes (PROM).

METHODS

A retrospective, population-based cohort study was conducted in Hebei, Zhejiang, and Jiangsu provinces in China from 1993 to 1995. After excluding women with missing data of exposure and outcome, history of chronic hypertension, multiple births, and babies with major birth defects and ambiguous sex, this study comprised 199 231 singleton live births. Logistic regression was used to evaluate the association, adjusting for potential confounders.

RESULTS

The incidence of PROM was 17.7% and 8.9% in women with gestational hypertension and pre-eclampsia, respectively, and 5.9% for the normotensive group. Compared with normotension, gestational hypertension was associated with an increase in the odds of PROM of 4.21 times (95% confidence interval [CI] 3.77-4.70), while pre-eclampsia had an increase of 2.27 times (95% CI 1.78-2.88). Additionally, women with hypertensive disorders of pregnancy had higher risks for term PROM (adjusted risk ratio [RR] 3.83, 95% CI 3.43-4.27) than preterm PROM (adjusted RR 3.10, 95% CI 2.18-4.41). Consistent results of the association were also observed in the sensitivity analyses.

CONCLUSION

Gestational hypertension and pre-eclampsia were associated with an increased risk for PROM. Increased odds were observed for term PROM compared with preterm PROM.

Maternal hypertensive disorders in pregnancy and risk of hypoxic-ischemia encephalopathy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is one of the most serious birth complications for neonates. Few studies reported the relationship between maternal blood pressure disorders and risk of neonatal HIE.

OBJECTIVE

This study was conducted to examine whether maternal hypertensive disorders in pregnancy increase the risk of HIE.

METHODS

The analyses were performed using data from a large population-based cohort study aiming to prevent neural tube defects by supplementation with folic acid. The subjects comprised 183,981 women with singleton live births delivered at gestational ages of 32-42 weeks, who registered in two southern provinces in China. Blood pressure was measured by trained health care workers at each prenatal visit. Diagnosis information on HIE was recorded at the time of delivery.

RESULTS

Totally 19,298 women (10.49%) were diagnosed with maternal hypertensive disorders in pregnancy and 255 infants (1.4 per 1000) with HIE, respectively. Compared with the normotensive group, a great increment in the risk of HIE was observed in women with hypertensive disorders (adjusted RR = 2.40, 95% confidence interval [CI]: 1.79-3.22) after adjusting for maternal confounding factors. A greater association was presented among preterm (32-36 weeks) infants with an adjusted RR of 5.45 (95% CI: 2.79, 10.65) compared to a RR of 2.09 (95% CI: 1.49, 2.92) among full-term (37-42 weeks) infants (p for heterogeneity < .05). Further stratification analyses showed that no matter with or without small for gestational age (SGA), maternal hypertensive disorders were associated with the increased risk for HIE. Sensitivity analyses excluding infants with low or high birth weight did not appreciably change the findings.

CONCLUSIONS

Our present study demonstrated a positive association of maternal hypertensive disorders in pregnancy with the risk of neonatal HIE.

Vegetable dietary pattern associated with low risk of preeclampsia possibly through reducing proteinuria

BACKGROUND

Evidence on the potential roles that dietary patterns play in the risk of preeclampsia remains limited.

OBJECTIVE

To examine the associations between dietary patterns during pregnancy and the risk of preeclampsia.

STUDY DESIGN

We analyzed data from a cluster randomized controlled trial among 987 healthy pregnant women in three rural counties in northwestern China. Maternal diet during the whole pregnancy was assessed using a 107-item food frequency questionnaire with proportion size administered before delivery. Principal component factor analysis with varimax rotation was used to identify common dietary patterns. Preeclampsia was diagnosed by trained clinicians and recorded in delivery records.

RESULTS

Nineteen participants (1.9%) were diagnosed with preeclampsia. Gestational hypertension and proteinuria were only weakly correlated with each other (Kappa = 0.06): 10.7% participants with gestational hypertension only, 8.8% with proteinuria only, 1.9% with both, and 78.6% with neither. Five common dietary patterns were identified: vegetable, meat, fruit, snack, and wheat staple patterns. After adjusting for calories, other dietary pattern scores and baseline blood pressure, a higher vegetable pattern scores was associated with lower risk of preeclampsia (P for trend = 0.041; the highest vs lowest quartile, adjusted relative risk = 0.20 [95% confidence interval, 0.04-0.98]). A similar association was also observed for the risk of proteinuria (P for trend = 0.015): the highest vs lowest quartiles of the vegetable pattern score, adjusted relative risk = 0.44 (95% confidence interval, 0.24-0.80). The other four pattern scores were not associated with preeclampsia.

CONCLUSIONS

Adherence to vegetable dietary pattern may be associated with the lower risk of preeclampsia, possibly through reducing development of proteinuria. The original full study was registered at clinicaltrials.gov as NCT02537392.

Association of pre-eclampsia risk with maternal levels of folate, homocysteine and vitamin B12 in Colombia: A case-control study

BACKGROUND

Maternal serum concentrations of folate, homocysteine, and vitamin B12 have been associated with pre-eclampsia. Nevertheless, reported studies involve limited number of cases to reliably assess the nature of these associations. Our aim was to examine the relation of these three biomarkers with pre-eclampsia risk in a large Colombian population.

MATERIALS AND METHODS

Design: A case-control study. Setting: Cases of pre-eclampsia and healthy pregnant controls were recruited at the time of delivery from eight different Colombian cities between 2000 and 2012. Population or Sample: 2978 cases and 4096 controls were studied. Maternal serum concentrations of folate, homocysteine, and vitamin B12 were determined in 1148 (43.6%) cases and 1300 (31.7%) controls. Also, self-reported folic acid supplementation was recorded for 2563 (84%) cases and 3155 (84%) controls. Analysis: Adjusted odds ratios (OR) for pre-eclampsia were estimated for one standard deviation (1SD) increase in log-transformed biomarkers. Furthermore, we conducted analyses to compare women that reported taking folic acid supplementation for different periods during pregnancy. Main Outcomes Measures: Odds ratio for pre-eclampsia.

RESULTS

After adjusting for potential confounders in logistic regression models, the OR for pre-eclampsia was 0.80 (95% CI: 0.72, 0.90) for 1SD increase in log-folate, 1.16 (95%CI: 1.05, 1.27) for 1SD increase in log-homocysteine, and 1.10 (95%CI: 0.99, 1.22) for 1SD increase in log-vitamin B12. No interactions among the biomarkers were identified. Women who self-reported consumption of folic acid (1 mg/day) throughout their pregnancy had an adjusted OR for pre-eclampsia of 0.86 (95%CI: 0.67, 1.09) compared to women that reported no consumption of folic acid at any point during pregnancy.

CONCLUSIONS

Maternal serum concentrations of folate were associated as a protective factor for pre-eclampsia while concentrations of homocysteine were associated as a risk factor. No association between maternal vitamin B12 concentrations and preeclampsia was found.

Effect of high dose folic acid supplementation in pregnancy on pre-eclampsia (FACT): double blind, phase III, randomised controlled, international, multicentre trial

OBJECTIVE

To determine the efficacy of high dose folic acid supplementation for prevention of pre-eclampsia in women with at least one risk factor: pre-existing hypertension, prepregnancy diabetes (type 1 or 2), twin pregnancy, pre-eclampsia in a previous pregnancy, or body mass index ≥35.

DESIGN

Randomised, phase III, double blinded international, multicentre clinical trial.

SETTING

70 obstetrical centres in five countries (Argentina, Australia, Canada, Jamaica, and UK).

PARTICIPANTS

2464 pregnant women with at least one high risk factor for pre-eclampsia were randomised between 2011 and 2015 (1144 to the folic acid group and 1157 to the placebo group); 2301 were included in the intention to treat analyses.

INTERVENTION

Eligible women were randomised to receive either daily high dose folic acid (four 1.0 mg oral tablets) or placebo from eight weeks of gestation to the end of week 16 of gestation until delivery. Clinicians, participants, adjudicators, and study staff were masked to study treatment allocation.

MAIN OUTCOME MEASURE

The primary outcome was pre-eclampsia, defined as hypertension presenting after 20 weeks' gestation with major proteinuria or HELLP syndrome (haemolysis, elevated liver enzymes, low platelets).

RESULTS

Pre-eclampsia occurred in 169/1144 (14.8%) women in the folic acid group and 156/1157 (13.5%) in the placebo group (relative risk 1.10, 95% confidence interval 0.90 to 1.34; P=0.37). There was no evidence of differences between the groups for any other adverse maternal or neonatal outcomes.

CONCLUSION

Supplementation with 4.0 mg/day folic acid beyond the first trimester does not prevent pre-eclampsia in women at high risk for this condition.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN23781770 and ClinicalTrials.gov NCT01355159.

Supplementation of folic acid in pregnancy and the risk of preeclampsia and gestational hypertension: a meta-analysis

OBJECTIVES

We aimed to systematically assess the relationship between folic acid supplementation in pregnancy and risk of preeclampsia and gestational hypertension.

METHODS

The relevant studies were included by retrieving the Embase, PubMed and Cochrane library databases. Data extraction was conducted by two investigators independently. The risk ratio (RR) and 95% confidence interval (CI) were used as effect indexes to evaluate the relationship between folic acid supplementation and risk of gestational hypertension or preeclampsia. A subgroup analysis was performed according to the supplementation patterns of folic acid. The homogeneity of the effect size was tested across the studies, and publication biases were examined.

RESULTS

In total, 13 cohort studies and 1 randomized controlled trial study was included, containing 160,562 and 149,320 women with and without folic acid supplementation during pregnancy. Pooled results showed that risk of gestational hypertension was not associated with the supplementation of folic acid. However, folic acid supplementation during pregnancy could significantly reduce the risk of preeclampsia. Moreover, the results of subgroup analysis showed that the decreased preeclampsia risk was associated with supplementation of multivitamins containing folic acid rather than folic acid alone.

CONCLUSIONS

Our findings indicate that the supplementation of multivitamins containing folic acid during pregnancy could significantly lower preeclampsia risk.

Maternal folic acid supplementation for the prevention of preeclampsia: A systematic review and meta-analysis

BACKGROUND

Preeclampsia is a significant contributor to maternal and neonatal morbidity and mortality. Folic acid supplementation is recommended periconceptionally for the prevention of neural tube defects. Epidemiological evidence suggests that maternal folic acid supplementation may play a role in preventing other adverse birth outcomes. This systematic review aimed to investigate the effect of maternal folic acid supplementation during pregnancy on risk of preeclampsia and gestational hypertension.

METHODS

Multiple scientific databases and grey literature were searched for relevant studies. Studies were reviewed according to pre-specified inclusion and exclusion criteria. Study characteristics were summarised and study quality was assessed. A meta-analysis of observational studies was conducted to examine the effect of maternal folic acid supplementation on preeclampsia risk.

RESULTS

Meta-analysis of eight observational studies showed significantly lower odds of preeclampsia with folic acid supplementation in comparison to no folic acid supplementation: OR = 0.78 (95% CI 0.63, 0.98), with moderately high heterogeneity between studies. Subgroup analysis showed no significant subgroup difference between folic acid supplementation taken by itself, in comparison to folic acid taken in or alongside a multivitamin.

CONCLUSION

Low level evidence is available for a modest association between maternal folic acid supplementation and reduction in preeclampsia risk. Future studies should differentiate between early and late onset and mild vs severe preeclampsia, and should control for relevant confounders including the presence of multivitamin supplements. The protocol for this systematic review was prospectively registered with PROSPERO (CRD42015029310).

Effects of prenatal exposure to air pollution on preeclampsia in Shenzhen, China

The impact of ambient air pollution on pregnant women is a concern in China. However, little is known about the association between air pollution and preeclampsia and the potential modifying effects of meteorological conditions have not been assessed. This study aimed to assess the effects of prenatal exposure to air pollution on preeclampsia, and to explore whether temperature and humidity modify the effects. We performed a retrospective cohort study based on 1.21 million singleton births from the birth registration system in Shenzhen, China, between 2005 and 2012. Daily average measurements of particulate matter <10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), air temperature (T), and dew point (T_d) were collected. Logistic regression models were performed to estimate associations between air pollution and preeclampsia during the first and second trimesters, and during the entire pregnancy. In each time window, we observed a positive gradient of increasing preeclampsia risk with increasing quartiles of PM₁₀ and SO₂ exposure. When stratified by T and T_d in three categories (<5th, 5th -95th, and >95th percentile), we found a significant interaction between PM₁₀ and T_d on preeclampsia; the adverse effects of PM₁₀ increased with T_d. During the entire pregnancy, there was a null association between PM₁₀ and preeclampsia under T_d < 5th percentile. Preeclampsia risk increased by 23% (95% CI: 19-26%) when 5th < T_d < 95th percentile, and by 34% (16-55%) when T_d > 95th percentile. We also found that air pollution effects on preeclampsia in autumn/winter seasons were stronger than those in the spring/summer. This is the first study to address modifying effects of meteorological factors on the association between air pollution and preeclampsia. Findings indicate that prenatal exposure to PM₁₀ and SO₂ increase preeclampsia risk in Shenzhen, China, and the effects could be modified by humidity. Pregnant women should limit air pollution exposure, particularly during humid periods.

Micronutrient supplementation during pregnancy and the risk of pregnancy-induced hypertension: A randomized clinical trial

BACKGROUND & AIMS

Increasing evidence suggests that iron-containing multiple micronutrient may reduce the risk of pregnancy-induced hypertension including gestational hypertension or preeclampsia. We aimed to examine whether 30 mg iron plus folic acid or multiple micronutrients during pregnancy reduces the risk of pregnancy-induced hypertension.

METHODS

We conducted a secondary data analysis by the dataset from a double-blind randomized controlled trial in China from 2006 to 2009 that was conducted to investigate the effects of multiple micronutrient supplements on adverse pregnancy outcomes when provided to pregnant women with no/mild anemia. We used logistic regression to estimate the adjusted odds ratio and 95% confidence interval and test for effect modification.

RESULTS

The incidence of pregnancy-induced hypertension was 7.1% (423/5923), 6.3% (374/5933) and 6.3% (372/5914) among the pregnant women who took folic acid only, iron-folic acid and multiple micronutrient supplements, respectively. The adjusted odds ratios associated with iron-folic acid supplements and multiple micronutrient supplements for pregnancy-induced hypertension were both nearly 0.88 (95% confidence interval, 0.76-1.02), compared with folic acid supplements only. Among pregnant women aged 20-24 years, iron-folic acid (adjusted odds ratios: 0.81, 95% confidence interval: 0.67-0.96) or multiple micronutrient supplementation (adjusted odds ratios: 0.83, 95% confidence interval: 0.70-0.99) can significantly reduce the risk of pregnancy-induced hypertension compared to folic acid supplementation.

CONCLUSIONS

Overall, there were no significant differences in pregnancy-induced hypertension across supplement groups. However, among pregnant women aged 20-24 years, iron-containing multiple micronutrient supplementation was associated with a reduced risk of pregnancy-induced hypertension compared with folic acid supplements only.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00133744.

Vitamins supplementation affects the onset of preeclampsia

Preeclampsia may affect between 2-8% of all pregnancies. It seriously affects maternal health after pregnancy. This meta-analysis was performed to define the efficacy of vitamins supplementation on the risk of preeclampsia. Potential articles were systematically searched on the databases of Pubmed, Embase and Web of Science up to May 2016. Relative risk (RR) and 95% confidence intervals (95%CIs) were used to analyze the relationship of vitamins supplementation with risk of preeclampsia. Cochran Q test was used to test inter-study heterogeneity. Begg's funnel plot was adopted to assess the potential publication bias. 28 eligible studies were selected. Pooled results indicated that vitamins supplementation could reduce the risk of preeclampsia (RR = 0.74, 95%CI = 0.64-0.86). The studies with non-randomized controlled trial (RCT) analysis also suggested the significant relationship of vitamins supplementation with risk of preeclampsia (RR = 0.60, 95%CI = 0.42-0.85). However, negative results were observed in studies with RCT analysis. Subgroup analysis by vitamin type was performed among the studies with RCT analysis. The results indicated that vitamin D supplementation could significantly reduce the risk of preeclampsia (RR = 0.41, 95%CI = 0.22-0.78). Similar results were observed in the studies with multivitamins supplementation (RR = 0.69, 95%CI = 0.51-0.93). Vitamins supplementation could reduce the onset of preeclampsia.

Folic acid supplement use and the risk of gestational hypertension and preeclampsia

BACKGROUND

Hypertensive disorders of pregnancy are among the leading causes of maternal morbidity and mortality. Studies suggest that the use of folic acid may lower the risk of hypertensive disorders in pregnant women.

AIM

The aim of this study was to assess the effects of timing and duration of folic acid-containing supplement use on the risk for gestational hypertension and preeclampsia.

METHODS

Exposures and outcomes data were obtained through interviews and review of participant's medical records from the MotherToBaby cohort studies across the United States and Canada. Demographics, medical history, lifestyle factors, substance use, and fetal sex were assessed as potential confounders. Unadjusted and adjusted risks for gestational hypertension and preeclampsia were examined using odds ratios and 95% confidence intervals.

FINDINGS

3247 women were included in the study. Compared to non-supplement use, early and late supplement use were not significantly associated with the development of gestational hypertension or preeclampsia. The odds of developing gestational hypertension and preeclampsia were significantly reduced as the duration of folic acid-containing supplement use increased.

CONCLUSION

Findings from this study suggest that the use of folic acid-containing supplements may mitigate the risk for gestational hypertension and preeclampsia.

The impact of folic acid supplementation on gestational and long term health: Critical temporal windows, benefits and risks

Highlights

Associations between FA supplementation in pregnancy and effects on offspring's NTDs, allergy/respiratory problems, cancer and behaviour problems as been studied.There is growing concern about the effects of excessive FA supplementation, whether in terms of doses or times of exposure.FA supplementation in the periconceptional period is protective against NTDs while in later periods it could be deleterious.A daily dose of 0.4 mg FA in the periconceptional period seems to be effective and safe.

Abstract

Maternal folic acid (FA) supplementation is one of the most popular nutritional interventions during pregnancy for its protective effect against neural tube defects (NTDs).The purposes of this review are: (a) to gather the current evidence regarding supplementation of maternal diet with FA and (b) to problematize the available literature in terms of dosages, critical temporal windows, and its potential benefits and risks.The expression (pregnancy OR fetus OR offspring OR mother) AND ("folic acid" AND supplementation) was searched on PubMed database, filtering for articles published from 2005 to 2014. Publications referring to FA supplementation during the periconceptional period or pregnancy in which there was a conclusion about the effects of isolated FA supplementation on pregnant woman, pregnancy or offspring were included. Of the initial 1182 papers, 109 fulfilled the inclusion criteria.The majority of the publications reported FA supplementation outcomes on offspring's health, with emphasis in NTDs, allergy/respiratory problems, cancer and behaviour problems. Some inconsistency is observed on the impact of FA supplementation on different outcomes, except for NTDs. It is also visible an increased concern about the impact of excessive supplementation, either in terms of doses or exposure's duration.In conclusion, there is a growing interest in FA supplementation issues. The protective effect of FA supplementation over NTDs has been confirmed, being the periconceptional period a critical window, and it is frequently suggested that allergy/respiratory outcomes arise from (excessive) FA supplementation particularly later in pregnancy. Further research on critical doses and time of exposure should be conducted.

Pregnancy: An Underutilized Window of Opportunity to Improve Long-term Maternal and Infant Health-An Appeal for Continuous Family Care and Interdisciplinary Communication

Physiologic adaptations during pregnancy unmask a woman's predisposition to diseases. Complications are increasingly predicted by first-trimester algorithms, amplify a pre-existing maternal phenotype and accelerate risks for chronic diseases in the offspring up to adulthood (Barker hypothesis). Recent evidence suggests that vice versa, pregnancy diseases also indicate maternal and even grandparent's risks for chronic diseases (reverse Barker hypothesis). Pub-Med and Embase were reviewed for Mesh terms "fetal programming" and "pregnancy complications combined with maternal disease" until January 2017. Studies linking pregnancy complications to future cardiovascular, metabolic, and thrombotic risks for mother and offspring were reviewed. Women with a history of miscarriage, fetal growth restriction, preeclampsia, preterm delivery, obesity, excessive gestational weight gain, gestational diabetes, subfertility, and thrombophilia more frequently demonstrate with echocardiographic abnormalities, higher fasting insulin, deviating lipids or clotting factors and show defective endothelial function. Thrombophilia hints to thrombotic risks in later life. Pregnancy abnormalities correlate with future cardiovascular and metabolic complications and earlier mortality. Conversely, women with a normal pregnancy have lower rates of subsequent diseases than the general female population creating the term: "Pregnancy as a window for future health." Although the placenta works as a gatekeeper, many pregnancy complications may lead to sickness and earlier death in later life when the child becomes an adult. The epigenetic mechanisms and the mismatch between pre- and postnatal life have created the term "fetal origin of adult disease." Up to now, the impact of cardiovascular, metabolic, or thrombotic risk profiles has been investigated separately for mother and child. In this manuscript, we strive to illustrate the consequences for both, fetus and mother within a cohesive perspective and thus try to demonstrate the complex interrelationship of genetics and epigenetics for long-term health of societies and future generations. Maternal-fetal medicine specialists should have a key role in the prevention of non-communicable diseases by implementing a framework for patient consultation and interdisciplinary networks. Health-care providers and policy makers should increasingly invest in a stratified primary prevention and follow-up to reduce the increasing number of manifest cardiovascular and metabolic diseases and to prevent waste of health-care resources.

Supplémentation préconceptionnelle en acide folique / multivitamines pour la prévention primaire et secondaire des anomalies du tube neural et d'autres anomalies congénitales sensibles à l'acide folique

OBJECTIF

Offrir des renseignements à jour sur l'utilisation pré et postconceptionnelle d'acide folique par voie orale, avec ou sans supplément de multivitamines / micronutriments, aux fins de la prévention des anomalies du tube neural et d'autres anomalies congénitales. Ces renseignements aideront les médecins, les sages-femmes, les infirmières et les autres professionnels de la santé à contribuer aux efforts de sensibilisation des femmes quant à l'utilisation et aux posologies adéquates de la supplémentation en acide folique / multivitamines, avant et pendant la grossesse. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, Medline, CINAHL et la Cochrane Library en janvier 2011 au moyen d'un vocabulaire contrôlé et de mots clés appropriés (p. ex. « folic acid », « prenatal multivitamins », « folate sensitive birth defects », « congenital anomaly risk reduction », « pre-conception counselling »). Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre 1985 et juin 2014. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en juin 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques, et auprès de sociétés de spécialité médicale nationales et internationales. COûTS, RISQUES ET AVANTAGES: Les coûts financiers sont ceux de la supplémentation quotidienne en vitamines et de la consommation d'un régime alimentaire santé enrichi en folate. Les risques sont ceux qui sont liés à une association signalée entre la supplémentation alimentaire en acide folique et des modifications épigénétiques fœtales / la probabilité accrue d'obtenir une grossesse gémellaire. Ces associations pourraient devoir être prises en considération avant la mise en œuvre d'une supplémentation en acide folique. La supplémentation en acide folique par voie orale (ou l'apport alimentaire en folate combiné à un supplément de multivitamines / micronutriments) a pour avantage de mener à une baisse connexe du taux d'anomalies du tube neural et peut-être même des taux d'autres complications obstétricales et anomalies congénitales particulières.

VALEURS

La qualité des résultats est évaluée au moyen des critères décrits par le Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). DéCLARATION SOMMAIRE: RECOMMANDATIONS.

Comparison of high dose and low dose folic acid supplementation on prevalence, onset and severity of preeclampsia

BACKGROUND

Folic acid supplementation had previously mentioned as a protective factor against the onset of preeclampsia (PE). In this study, we aimed to compare the effect of high dose (5 mg daily) and low dose (1 mg daily) of folic acid supplementation on prevalence, onset and severity of PE.

MATERIALS AND METHODS

Pregnant women who were in the first trimester and referred to prenatal care university hospitals of Isfahan, Iran during October 2013-May 2015 were included in this study, then they were randomly divided into two groups of 5 mg and 1 mg (treated with daily 5 mg and 1 mg of folic acid, respectively), both groups received folic acid from the first trimester of pregnancy to 42 days after termination. Blood pressure, body mass index (BMI), and some urine and blood biochemistry parameters were measured. SPSS-22 used for statistical analysis.

RESULTS

A total of 943 pregnant women participated in the study (450 women in 1 mg group and 450 women in 5 mg group). Incidence rate of PE was 3.8% in 1 mg group and 2.4% in 5 mg group. In a comparison of preeclamptic patients in 1 mg and 5 mg group, no significant differences were seen regarding age, BMI, laboratory data, the severity of the disease, and onset (early or late) (P > 0.05).

CONCLUSION

Although our findings support that administration of high dose folic acid may decrease the prevalence of PE, there is not enough data to support that higher amount of folic acid administration can reduce the severity of presentation's signs or ameliorate the laboratory data and the onset of PE.

Evaluation of the effect of high-dose folic acid on endothelial dysfunction in pre-eclamptic patients: A randomized clinical trial

Background:

Pre-eclampsia as a hypertensive disorder of pregnancy complicates up to 5–10% of pregnancies worldwide. Endothelial dysfunction plays an important role in the pathogenesis of pre-eclampsia. In this study, we aim to evaluate the effect of high-dose folic acid on endothelial dysfunction in pre-eclamptic patients.

Materials and Methods:

In this triple-blinded randomized clinical trial, the enrolled patients were divided randomly into two groups. Folic acid 5.0 mg or placebo was taken daily by oral administration from the initiation of diagnosis until 2 months after delivery by the participants. Every patient's flow-mediated dilation (FMD) was evaluated at the beginning of the study and 2 months after delivery with the same experienced operator at the same period of time (3–5 p.m.) by high-resolution B-mode ultrasonography. Potential confounding variables were included in the independent samples t-test. t-test or Mann–Whitney U-test was used in the comparison of means between the intervention and placebo groups. To compare FMD in each group, before and after the intervention, paired t-test was used.

Results:

Mean value of FMD in intervention (9.64 ± 5.57) and control group (9.30 ± 4.25) has no significant difference before the consumption of drugs (P > 0.05). FMD in intervention group (13.72 ± 7.89) significantly increases after daily consumption of 5 mg folic acid in comparison with control group (10.02 ± 4.81) after daily consumption of placebo (P = 0.002).

Conclusion:

Increased mean of FMD in intervention group shows that this supplement can improve endothelial function and can be significantly affected by maternal blood pressure during pregnancy and some endothelium-dependent disease such as pre-eclampsia and its associated adverse outcomes.

Preconception Blood Pressure and Risk of Low Birth Weight and Small for Gestational Age

Our objective was to examine whether high blood pressure in the preconception period was associated with low birth weight (LBW) and small-for-gestational age (SGA) in Chinese women. Data were obtained from the China–US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. We included 43 718 singleton live births delivered at gestational ages of 28−45 weeks to women who were registered before pregnancy in 7 counties in southern China. Blood pressure was measured during registration by trained healthcare workers, and other health-related information was recorded prospectively. We used logistic regression to evaluate the associations between preconception blood pressure and the risk of LBW and SGA, adjusting for potential confounders. The prevalence of hypertension in the preconception study population was 4.62% (2019/43 718). The incidences of LBW and SGA were 2.33% and 5.05% for the hypertension group and 2.01% and 5.68% for the nonhypertension group. Compared with the nonhypertension group, the hypertension group did not show significantly increased risk for LBW overall (adjusted risk ratio =1.16, 95% confidence interval 0.86−1.57) or SGA (adjusted risk ratio =0.89, 95% confidence interval 0.73−1.09). When participants with normal blood pressure were used as the reference, the adjusted risk ratio of SGA for prehypertensive women was 1.13 (95% confidence interval 1.03−1.25). Our results do not support an association between hypertension or higher blood pressure before pregnancy and increased risk of LBW or SGA.

Are hypertensive disorders in pregnancy associated with congenital malformations in offspring? Evidence from the WHO Multicountry cross sectional survey on maternal and newborn health

BACKGROUND

Annually, around 7.9 million children are born with birth defects and the contribution of congenital malformations to neonatal mortality is generally high. Congenital malformations in children born to mothers with hypertensive disorders during pregnancy has marginally been explored.

METHODS

Country incidence of congenital malformations was estimated using data on the 310 401 livebirths of the WHO Multicountry Survey which reported information from 359 facilities across 29 countries. A random-effect logistic regression model was utilized to explore the associations between six broad categories of congenital malformations and the four maternal hypertensive disorders "Chronic Hypertension", "Preeclampsia" and "Eclampsia" and "Chronic hypertension with superimposed preeclampsia".

RESULTS

The occupied territories of Palestine presented the highest rates in all groups of malformation except for the "Lip/Cleft/Palate" category. Newborns of women with chronic maternal hypertension were associated with a 3.7 (95 % CI 1.3-10.7), 3.9 (95 % CI 1.7-9.0) and 4.2 (95 % CI 1.5-11.6) times increase in odds of renal, limb and lip/cleft/palate malformations respectively. Chronic hypertension with superimposed preeclampsia was associated with a 4.3 (95 % CI 1.3-14.4), 8.7 (95 % CI 2.5-30.2), 7.1 (95 % CI 2.1-23.5) and 8.2 (95 % CI 2.0-34.3) times increase in odds of neural tube/central nervous system, renal, limb and Lip/Cleft/Palate malformations.

CONCLUSIONS

This study shows that chronic hypertension in the maternal period exposes newborns to a significant risk of developing renal, limb and lip/cleft/palate congenital malformations, and the risk is further exacerbate by superimposing eclampsia. Additional research is needed to identify shared pathways of maternal hypertensive disorders and congenital malformations.

Effect of folic acid supplementation during pregnancy on gestational hypertension/preeclampsia: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of folic acid supplementation during pregnancy on the risk of gestational hypertension/preeclampsia.

METHODS

A systematic review and meta-analysis were conducted. Medline, Embase, Scopus, and the Web of Science were searched from inception to December 2014.

RESULTS

Out of 1224 potentially relevant studies, 13 studies met our inclusion criteria (2 randomized controlled trials (RCTs), 10 cohort studies, and 1 case-control study). The pooled relative risk (RR) and 95% confidence interval (CI) of the two RCTs were 0.62 (0.45-0.87) in the trial arm as compared with the placebo arm. The pooled RR was 0.92 (95% CI: 0.79-1.08) for nine cohort studies with available data on folic acid supplementation in pregnancy and gestational hypertension/preeclampsia. Pooled RR was 0.88 (95% CI: 0.76-1.02) for eight cohort studies with available data on folic acid supplementation and preeclampsia.

CONCLUSION

Whether folic acid supplementation in pregnancy can prevent the occurrence of gestational hypertension/preeclampsia remains uncertain.

Maternal supplementation of omega-3 fatty acids and micronutrients reduces cardiometabolic variables in pregnancy induced hypertension rats

AIMS

Reports indicate that during pregnancy hypertension is known to have long term adverse effects both in the mother and offspring. However, the effect of maternal micronutrient supplementation on this association of in utero exposure and risk of non-communicable diseases in the later life remains unclear. The present study examines the effect of maternal micronutrient and omega-3 fatty acid supplementation either individual or in combination on cardiometabolic risk factors both in the mother and offspring using an animal model of hypertension.

MAIN METHODS

Pregnant Wistar rats were randomly assigned to the following groups; control, PIH (Pregnancy induced hypertention) Induced, PIH+vitamin B12, PIH+ folic acid, PIH+omega-3 fatty acids and PIH+combined smicronutrient supplementation (vitamin B12+folic acid + omega-3 fatty acids). The dams and their offspring were shifted to a control diet after delivery and the offspring continued on these diets till 3mo of age. Hypertension during pregnancy was induced using l-Nitroarginine methylester (50mg/kgbody weight/day).

KEY FINDINGS

Omega-3 fatty acid supplementation during pregnancy demonstrated lower levels (p<0.05) of plasma cholesterol while a combined supplementation of folic acid, vitamin B12 and omega 3 fatty acids demonstrated lower (p<0.05) triglyceride levels as compared to PIH induced dams. PIH induction increased (p<0.01) the triglyceride levels in the offspring at 3mo of age and maternal supplementation of either individual or combined micronutrients demonstrated lower (p<0.01) triglyceride levels.

SIGNIFICANCE

Our findings have implications for planning intervention studies in women with pregnancy induced hypertension.

The Effect of High Dose Folic Acid throughout Pregnancy on Homocysteine (Hcy) Concentration and Pre-Eclampsia: A Randomized Clinical Trial

Pre-eclampsia is a pregnancy-related multi-systemic hypertensive disorder and affects at least 5% of pregnancies. This randomized clinical trial aimed at assessing the effect of low doses and high doses of folic acid on homocysteine (Hcy) levels, blood pressure, urea, creatinine and neonatal outcome. A randomized clinical trial was done at Alzahra Teaching Hospital, Tabriz University of Medical Sciences from April 2008 to March 2013. Four-hundred and sixty nulliparous pregnant women were randomly assigned into two groups. Group 1 (n = 230) received 0.5 mg of folic acid and group 2 (n = 230) received 5 mg of folic acid per daily. They were followed until delivery. Blood pressure and laboratory changes, including plasma Hcy levels, were measured and compared between the groups. Homocysteine concentrations were significantly higher at the time of delivery in group 1 (13.17±3.89 μmol/l) than in group 2 (10.31±3.54, μmol/l) (p<0.001). No statistically significant differences were observed in systolic and diastolic blood pressure (p = 0.84 and 0.15, respectively). Birth weight was significantly higher in group 2 (p = 0.031) and early abortion was significantly higher in group 1 than group 2 (p = 0.001). This study has provided evidence that a high dosage of folic acid supplements throughout pregnancy reduces Hcy concentrations at the time of delivery.

Trial Registration: Iranian Registry of Clinical Trials IRCT201402175283N9

Folic acid supplementation: what is new? Fetal, obstetric, long-term benefits and risks

The association between folic acid supplementation, prior to conception and/or during pregnancy and pregnancy outcomes, has been the subject of numerous studies. The worldwide recommendation of folic acid is at least 0.4 mg daily for all women of reproductive age, and 4–5 mg in high-risk women. In addition, evidence shows that folic acid supplementation could modulate other adverse pregnancy outcomes, specifically, in pregnancies complicated by seizure disorders, preeclampsia, anemia, fetal growth restriction and autism. This review summarizes the available national and international guidelines, concerning the indications and dosage of folic acid supplementation during pregnancy. In addition, it describes the potential preventive benefits of folic acid supplementation on multiple maternal and fetal outcomes, as well as potential risks.

Epigenetic Biomarkers of Preterm Birth and Its Risk Factors

A biomarker is a biological measure predictive of a normal or pathogenic process or response. Biomarkers are often useful for making clinical decisions and determining treatment course. One area where such biomarkers would be particularly useful is in identifying women at risk for preterm delivery and related pregnancy complications. Neonates born preterm have significant morbidity and mortality, both in the perinatal period and throughout the life course, and identifying women at risk of delivering preterm may allow for targeted interventions to prevent or delay preterm birth (PTB). In addition to identifying those at increased risk for preterm birth, biomarkers may be able to distinguish neonates at particular risk for future complications due to modifiable environmental factors, such as maternal smoking or alcohol use during pregnancy. Currently, there are no such biomarkers available, though candidate gene and epigenome-wide association studies have identified DNA methylation differences associated with PTB, its risk factors and its long-term outcomes. Further biomarker development is crucial to reducing the health burden associated with adverse intrauterine conditions and preterm birth, and the results of recent DNA methylation studies may advance that goal.

Folate status and health: challenges and opportunities

Each year approximately 2400 pregnancies develop folic acid-preventable spina bifida and anencephaly in Europe. Currently, 70% of all affected pregnancies are terminated after prenatal diagnosis. The prevalence of neural tube defects (NTDs) has been significantly lowered in more than 70 countries worldwide by applying fortification with folic acid. Periconceptional supplementation of folic acid also reduces the risk of congenital heart diseases, preterm birth, low birth weight, and health problems associated with child mortality and morbidity. All European governments failed to issue folic acid fortification of centrally processed and widely eaten foods in order to prevent NTDs and other unwanted birth outcomes. The estimated average dietary intake of folate in Germany is 200 μg dietary folate equivalents (DFE)/day. More than half of German women of reproductive age do not consume sufficient dietary folate to achieve optimal serum or red blood cell folate concentrations (>18 or 1000 nmol/L, respectively) necessary to prevent spina bifida and anencephaly. To date, targeted supplementation is recommended in Europe, but this approach failed to reduce the rate of NTDs during the last 10 years. Public health centers for prenatal care and fortification with folic acid in Europe are urgently needed. Only such an action will sufficiently improve folate status, prevent at least 50% of the NTD cases, reduce child mortality and morbidity, and alleviate other health problems associated with low folate such as anemia.

Folic acid alone or multivitamin containing folic acid intake during pregnancy and the risk of gestational hypertension and preeclampsia through meta-analyses

Objective

The objective of this study was to assess the effect of folic acid and multivitamin use during pregnancy on the risk of developing of hypertensive disorder of pregnancy.

Methods

Two reviewers independently determined all prospective cohort study, retrospective cohort study, large population based cohort study, retrospective secondary analysis, and double blinded, placebo-controlled, randomized clinical trial published using PubMed Medline database, KERIS (Korea Education and Research Information Service), Scopus, and the Cochrane Central Register of controlled trials comparing before conception throughout pregnancy intake oral multivitamin containing folic acid or folic acid alone. Meta-analyses were estimated with odds ratios and 95% confidence intervals (CIs) using random effect analysis according to heterogeneity of studies.

Results

Data from six effect sizes from six studies involving 201,661 patients were enrolled. These meta-analyses showed multivitamin containing folic acid or folic acid alone was not significantly effective in reducing gestational hypertension or preeclampsia incidence (odds ratio, 0.91; 95% CI, 0.81 to 1.03) than the placebo. And the difference of effective sizes of preeclampsia and gestational hypertension according to two dependent variables, multivitamin and folic acid were not significant, respectively (point estimate, 0.66; 95% CI, 0.46 to 0.96).

Conclusion

These meta-analyses demonstrate multivitamin containing folic acid or folic acid alone was not significantly effective in reducing gestational hypertension or preeclampsia incidence.

Effects of folic acid supplementation on serum homocysteine and lipoprotein (a) levels during pregnancy

Introduction:There are many ideas concerning the etiology and pathogenesis of preeclampsia including endothelial dysfunction, inflammation and angiogenesis. Elevated levels of total homocysteine (Hcy) and lipoprotein (a) [Lp(a)] are risk factors for endothelial dysfunction. This study aimed to evaluate the effect of high dose folic acid (FA) on serum Hcy and Lp(a) concentrations with respect to methylenetetrahydrofolate reductase (MTHFR) polymorphisms 677C→T during pregnancy.

Methods: In a prospective uncontrolled intervention, 90 pregnant women received 5 mg FA supplementation before pregnancy till 36th week of pregnancy. The MTHFR polymorphisms 677C→T, serum lactate dehydrogenase activity, urine protein and creatinine concentrations were measured before starting folic acid administration. Serum levels of Hcy and Lp(a) were determined before and after completion of folic acid supplementation period.

Results: Supplementation of the patients with FA for 36 week decreased the median (minimum– maximum) levels of serum Hcy from 11.40 μmol/L (4.40-28.70) to 9.70 (1.60-20.80) μmol/L (p=0.001). There was no significant change in serum Lp(a) after FA supplementation (p=0.17). The overall prevalence of genotypes in pregnant women that were under study for MTHFR C677T polymorphism was 53.3% CC, 26.7% CT and 20.0% TT. There was no correlation between decreasing level of serum Hcy in the patients receiving FA and MTHFR polymorphisms.

Conclusion:Although FA supplementation decreased serum levels of Hcy in different MTHFR genotypes, serum Lp(a) was not changed by FA supplements. Our data suggests that FA supplementation effects on serum Hcy is MTHFR genotype independent in pregnant women.