Folic acid supplementation in pregnancy to prevent preterm birth: a systematic review and meta-analysis of randomized controlled trials

The association between preterm birth and the supplementation with vitamin D and calcium during pregnancy

BACKGROUND AND AIM

Although vitamin D (VD) supplementation or calcium supplementation during pregnancy has become publicly accepted and part of health care behavior, the effect of co-supplementation on preterm birth remains unclear.

OBJECTIVE

To explore whether the supplementation with vitamin D and calcium during pregnancy is associated with preterm birth.

METHODS

The study was the baseline survey from the birth cohort in Jinan, which was built at one month after the baby birth. Preterm birth and monthly VD and calcium supplementation during pregnancy were obtained by the questionnaire. The logistic model was conducted to exam the association. The distributed lag nonlinear model was applied to explore the critical window for the supplements.

RESULTS

Preterm birth occurred in 4.4 % (285/6501) of the study subjects with single live births and the rates were 39.7% and 82.6% for single VD supplementation or calcium supplementation in pregnancy. The adjusted OR (95% CI) for preterm birth was 1.428 (1.115-1.829) related to VD and 0.883 (0.652-1.216) related to calcium. It is interesting to note that the increased risk of preterm birth with VD supplementation during pregnancy was only seen in pregnant women who supplemented with calcium (OR was 1.600) and had a significant increase in preterm birth weight (P = 0.040). Besides, supplementation VD with calcium during pregnancy from the 3rd to 6th month during pregnancy was associated with preterm birth (OR3rd = 1.216, 95% CI: 1.119-1.320; OR4th = 1.275, 95% CI: 1.152-1.411; OR5th = 1.279, 95% CI: 1.130-1.446; OR6th = 1.208, 95% CI: 1.076-1.356). Moreover, birth weight mediated 10.8% of the total effect of supplementation on preterm birth.

CONCLUSION

Women who supplemented with VD among taking calcium during pregnancy were more likely to experience preterm birth, and birth weight partly mediates the effect. The critical window for association between supplements and preterm birth may be from the 3rd to 6th weeks of pregnancy.

Folate deficiency in pregnancy and the risk of preterm birth: A nested case-control study

Background

Preterm birth (PTB) and its complications are important public health problems. Its aetiology is multifactorial and involves both modifiable and non-modifiable factors. Among the modifiable risk factors, micronutrient deficiencies, including maternal folate deficiency, are increasingly being studied in PTB. In this study, we estimated the prevalence of folate deficiency during pregnancy and examined its association with PTB among rural Bangladeshi women.

Methods

We conducted a nested case-control study using data from a population-based cohort of 3000 pregnant women who were enrolled between 8 and 19 weeks of gestation following ultrasound confirmation of gestational age. Sociodemographic, epidemiologic, clinical, and pregnancy outcomes data were collected through home visits, while blood samples were collected at enrolment and 24-28 weeks of gestation during pregnancy. We included all women who delivered preterm (defined as live births <37 weeks of gestation) as cases (n = 235) and a random sample of women having a term birth as controls (n = 658). The main exposure was folate concentrations in maternal serum during 24-28 weeks of pregnancy. We categorised women into folate deficient (<3 ng/mL) and not deficient (≥3 ng/mL). We then performed multivariable logistic regression analysis to examine the association between maternal folate levels and PTB, adjusting for relevant covariates.

Results

Thirty-eight per cent of the enrolled pregnant women were folate deficient. Maternal serum folate deficiency was significantly associated with PTB (adjusted OR (aOR) = 1.73; 95% confidence interval (CI) = 1.27-2.36). The risk of PTB was also higher among women who were of short stature (aOR = 1.83; 95% CI = 1.27-2.63), primiparous (aOR = 1.60; 95% CI = 1.15-2.22), and had exposure to passive smoking (aOR = 1.54; 95% CI = 1.02-2.31).

Conclusions

The prevalence of folate deficiency was high among pregnant women in rural Bangladesh, and folate deficiency was significantly associated with an increased risk of preterm birth.

Cervical elastography using E-Cervix™ for prediction of preterm birth in twin pregnancies with threatened preterm labor

OBJECTIVE

To evaluate the prediction performance of E-Cervix™ for preterm birth in twin pregnancies with threatened preterm labor.

METHODS

This was a single-center retrospective cohort study of twin pregnancies presenting to obstetrics triage for threatened preterm labor (PTL) between 23 0/7 - 33 6/7 weeks who received screening for PTL with transvaginal ultrasound cervical length (TVU CL) and cervical elastography with E-Cervix™ at the time of triage. Cervical elastography parameters were examined and compared between women who delivered preterm and those who did not. The quantification of cervical strain was calculated by a data analysis system that directly analyzes raw data from the region of interest (ROI) and described as hardness ratio (HR), mean strain level within 1 cm from internal (IOS) and external (EOS) os.

RESULTS

63 twin gestations without prior preterm birth and with threatened PTL between 23 0/7 - 33 6/7 weeks of gestation were included in the study. 27 (42.9 %) had cervical length < 25 mm, and were admitted for true PLT. Out of the 36 women with cervical length ≥ 25 mm, 6 (16.7 %) were admitted. Women with threatened PTL had significantly higher HR compared to those with true PTL (p < 0.01), and significantly lower IOS and EOS. Women who delivered preterm had significantly higher HR compared to those who did not delivery preterm and significantly lower IOS and EOS, in overall cohort, and in the subset of women with true PTL. Incidences of HR < 50 % and < 35 % were statistically significantly higher in women who delivered preterm compared to those who did not (p < 0.01).

CONCLUSION

Cervical elastography with E-Cervix™ may be useful for assessment of twin gestations presenting to obstetrics triage for threatened PTL.

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.

Folic Acid and Risk of Preterm Birth, Preeclampsia, and Fetal Growth Restriction Among Women With Epilepsy: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES

Women with epilepsy treated with antiseizure medication (ASM) have increased risk of pregnancy complications including preterm birth, fetal growth restriction, and preeclampsia. We aimed to investigate whether folic acid supplementation is associated with these pregnancy complications in women with epilepsy using ASM.

METHODS

Singleton pregnancies in the prospective Norwegian Mother and Child Cohort Study (MoBa) (1999-2008) were included. Information on maternal epilepsy, ASM, folic acid supplementation, and pregnancy outcomes was obtained from the MoBa questionnaires and the Norwegian Medical Birth Registry. The main exposure, periconceptional folic acid supplementation, was defined as intake between 4 weeks before pregnancy and 12 weeks into pregnancy, retrospectively collected by recall of the mothers in weeks 17-19. The primary outcomes were preterm birth (gestational age <37 weeks at birth), small for gestational age (SGA), and preeclampsia.

RESULTS

The study included 100,105 pregnancies: 99,431 without maternal epilepsy, 316 with maternal epilepsy and ASM exposure in pregnancy, and 358 with untreated maternal epilepsy. Among ASM-treated women with epilepsy, the risk of preterm birth was higher in those who did not use periconceptional folic acid (n = 64) compared with those who did (n = 245, the reference) (adjusted odds ratio [aOR] 3.3, 95% CI 1.2-9.2), while the risk of preterm birth among the reference was similar to the risk among women without epilepsy using folic acid periconceptionally (aOR 0.9, 95% CI 0.5-1.6). ASM-treated women with epilepsy starting folic acid after the first trimester had a higher risk compared with women without epilepsy with similar timing of folic acid (aOR 2.6, 95% CI 1.1-6.5), and even higher if not using folic acid (aOR 9.4, 95% CI 2.6-34.8). Folic acid was not associated with risk of preterm birth among women with epilepsy without ASM or among women without epilepsy. Folic acid was not associated with risk of preeclampsia or SGA among women with epilepsy.

DISCUSSION

In women with epilepsy using ASM, periconceptional folic acid was associated with a lower risk of preterm birth. This finding supports the recommendation that ASM-treated women with epilepsy of childbearing potential should use folic acid supplementation on a regular basis.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for women with epilepsy using ASM, periconceptional folic acid supplementation decreases the risk of preterm birth.

Interventions for the prevention of spontaneous preterm birth: a scoping review of systematic reviews

BACKGROUND

Globally, 11% of babies are born preterm each year. Preterm birth (PTB) is a leading cause of neonatal death and under-five mortality and morbidity, with lifelong sequelae in those who survive. PTB disproportionately impacts low/middle-income countries (LMICs) where the burden is highest.

OBJECTIVES

This scoping review sought to the evidence for interventions that reduce the risk of PTB, focusing on the evidence from LMICs and describing how context is considered in evidence synthesis.

DESIGN

We conducted a scoping review, to describe this wide topic area. We searched five electronic databases (2009-2020) and contacted experts to identify relevant systematic reviews of interventions to reduce the risk of PTB. We included published systematic reviews that examined the effectiveness of interventions and their effect on reducing the risk of PTB. Data were extracted and is described narratively.

RESULTS

139 published systematic reviews were included in the review. Interventions were categorised as primary or secondary. The interventions where the results showed a greater effect size and consistency across review findings included treatment of syphilis and vaginal candidiasis, vitamin D supplementation and cervical cerclage. Included in the 139 reviews were 1372 unique primary source studies. 28% primary studies were undertaken in LMIC contexts and only 4.5% undertaken in a low-income country (LIC) Only 10.8% of the reviews sought to explore the impact of context on findings, and 19.4% reviews did not report the settings or the primary studies.

CONCLUSION

This scoping review highlights the lack of research evidence derived from contexts where the burden of PTB globally is greatest. The lack of rigour in addressing contextual applicability within systematic review methods is also highlighted. This presents a risk of inappropriate and unsafe recommendations for practice within these contexts. It also highlights a need for primary research, developing and testing interventions in LIC settings.

Oil-based vitamin E oral spray for oral health in pregnancy

Aim: To assess the efficacy of vitamin E oral spray in pregnancy. Materials & methods: This was a retrospective study aimed to evaluate efficacy of vitamin E oral spray (vitamin E acetate in a medium chain tryglicerides vehicle – patented formulation) starting from the first trimester of pregnancy, with a control group. Results: A total of 100 women were included in the study and were compared with a matched control group. Only 25/200 women reported to have at least one teeth cleaning during pregnancy. Women who received the oral spray had a significantly lower risk of preterm birth compared with the control group, and lower risk of periodontal diseases Conclusion: Use of oil-based vitamin E oral spray in pregnancy is associated with a decreased risk of periodontal diseases and therefore preterm birth.

Association of methylenetetrahydrofolate reductase gene polymorphisms and maternal folic acid use with the risk of congenital heart disease

BACKGROUND

To systematically evaluate the association of MTHFR genetic polymorphisms, maternal folic acid intake, and the time when folic acid intake was started with the risk of congenital heart disease (CHD) and investigated the role of their interaction on infant CHD risk in Chinese populations.

METHODS

A case-control study involving 592 CHD cases, 617 health controls, and their mothers was performed. The exposures of interest were single nucleotide polymorphisms (SNPs) of the MTHFR gene, maternal folic acid use, and the time when folic acid use was started. We applied the logistic regression model to explore the strength of association.

RESULTS

Our findings showed that mothers lacking folic acid intake had a significantly higher risk of CHD in offspring (aOR = 2.00; 95%CI: 1.34-2.98). Mothers who started to use folic acid from the first trimester of the fetation (aOR = 1.65; 95% CI: 1.22-2.23) or from the second trimester of the fetation (aOR = 7.77; 95% CI: 2.52-23.96), compared with those starting to use folic acid from 3 months previous to the conception, were at a significantly higher risk of CHD in offspring. Genetic variants at rs2066470 (AA vs. GG: aOR = 5.09, 95%CI: 1.99-13.03), rs1801133 (AA vs. GG: aOR = 2.49, 95%CI: 1.58-3.93), and rs1801131 (TG vs. TT: aOR = 1.84, 95%CI: 1.36-2.50; GG vs. TT: aOR = 3.58, 95%CI: 1.68-7.63) were significantly associated with the risk of CHD based on the multivariate analysis. Additionally, statistically significant interactions between maternal folic acid intake and genetic variants of the MTHFR gene at rs1801133 and rs1801131 were observed.

CONCLUSION

An association of maternal folic acid intake and the time when intake was started with the risk of CHD in offspring was found. What's more, maternal folic acid fortification may help counteract partial of the risks of CHD in offspring attributable to MTHFR genetic mutations.

REGISTRATION NUMBER

http://www.chictr.org.cn/edit.aspx?pid=28300&htm=4, identifier: ChiCTR1800016635.

Efficacy of 4.0 mg versus 0.4 mg Folic Acid Supplementation on the Reproductive Outcomes: A Randomized Controlled Trial

Folic acid (FA) supplementation prevents neural tube defects (NTDs), but the effects on other reproductive outcomes are unclear. While common recommendation is 0.4 mg/day in addition to regular nutrition, the most appropriate dose of FA is still under debate. We investigated the effects of a higher dose of periconception FA on reducing adverse reproductive outcomes. In this multicenter double-blind randomized controlled trial (RCT), 1060 women (aged 18-44 years and planning a pregnancy) were randomly assigned to receive 4.0 mg or 0.4 mg of FA daily. The primary outcome was the occurrence of congenital malformations (CMs). A composite outcome including one or more adverse pregnancy outcomes was also evaluated. A total of 431 women had a natural conception within 1 year. The primary outcome occurred in 8/227 (3.5%) women receiving 4.0 mg FA and 9/204 (4.4%) women receiving 0.4 mg FA (RR 0.80; 95%CI 0.31 to 2.03). The composite outcome occurred in 43/227 (18.9%) women receiving 4.0 mg FA and 75/204 (36.8%) women receiving 0.4 mg FA (RR 0.51; 95%CI 0.40 to 0.68). FA 4.0 mg supplementation was not associated with different occurrence of CMs, compared to FA 0.4 mg supplementation. However, FA 4.0 mg supplementation was associated with lower occurrence of other adverse pregnancy outcomes.

Folic acid supplementation during pregnancy and associations with offspring size at birth and adiposity: a cohort study

Objective

Previously we observed that maternal multiple micronutrient supplementation in pregnancy was associated with increased offspring size at birth and adiposity, as well as with maternal gestational diabetes risk, in the Cambridge Baby Growth Study. In this study we therefore investigated whether folic acid supplementation specifically is associated with similar changes, to test the hypothesis that folic acid supplementation mediates such changes.

Results

The majority of mothers who reported supplementing with folic acid in pregnancy (n = 776 in total, 526 of which took multiple micronutrient preparations) did so either from pre- (n = 139) or post-conception (n = 637) largely for all or just the first half of pregnancy. A minority of mothers (n = 198) reported not supplementing with folic acid. Folic acid supplementation in pregnancy was not associated with birth weight [β’ = − 0.003, p = 0.9], height [β’ = − 0.013, p = 0.6], head circumference [β’ = 0.003, p = 0.09] or adiposity (ponderal index [β’ = 0.020, p = 0.5], skinfolds thicknesses [β’ = − 0.029 to + 0.008, p = 0.4–0.9]). Neither was it associated with the development of maternal gestational diabetes (risk ratio 1.2 [0.6‒2.2], p = 0.6). These results suggest that folic acid supplementation in pregnancy did not mediate the previously observed increases in offspring size at birth and adiposity, or the raised gestational diabetes risk, in response to supplementation with multiple micronutrients.

Effects of Maternal Nutritional Supplements and Dietary Interventions on Placental Complications: An Umbrella Review, Meta-Analysis and Evidence Map

The placenta is a vital, multi-functional organ that acts as an interface between maternal and fetal circulation during pregnancy. Nutritional deficiencies during pregnancy alter placental development and function, leading to adverse pregnancy outcomes, such as pre-eclampsia, infants with small for gestational age and low birthweight, preterm birth, stillbirths and maternal mortality. Maternal nutritional supplementation may help to mitigate the risks, but the evidence base is difficult to navigate. The primary purpose of this umbrella review is to map the evidence on the effects of maternal nutritional supplements and dietary interventions on pregnancy outcomes related to placental disorders and maternal mortality. A systematic search was performed on seven electronic databases, the PROSPERO register and references lists of identified papers. The results were screened in a three-stage process based on title, abstract and full-text by two independent reviewers. Randomized controlled trial meta-analyses on the efficacy of maternal nutritional supplements or dietary interventions were included. There were 91 meta-analyses included, covering 23 types of supplements and three types of dietary interventions. We found evidence that supports supplementary vitamin D and/or calcium, omega-3, multiple micronutrients, lipid-based nutrients, and balanced protein energy in reducing the risks of adverse maternal and fetal health outcomes. However, these findings are limited by poor quality of evidence. Nutrient combinations show promise and support a paradigm shift to maternal dietary balance, rather than single micronutrient deficiencies, to improve maternal and fetal health. The review is registered at PROSPERO (CRD42020160887).

Association Between Folate and Health Outcomes: An Umbrella Review of Meta-Analyses

Background: There is no study that has systematically investigated the breadth and validity of the associations of folate and multiple health outcomes. We aimed to evaluate the quantity, validity, and credibility of evidence regarding associations between folate and multiple health outcomes by using umbrella review of meta-analysis. Methods: We searched the MEDLINE, EMBASE, and Cochrane Library databases from inception to May 20, 2018, to identify potential meta-analyses that examined the association of folate with any health outcome. For each included meta-analysis, we estimated the summary effect size and their 95% confidence interval using the DerSimonian and Laird random-effects model. We used the AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) to assess methodological quality and the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation working group classification) to assess the quality of evidence for each outcome included in the umbrella review. Results: Overall, 108 articles reporting 133 meta-analyses of observational studies and 154 meta-analyses of randomized controlled trials (RCTs) were included in the study. Among them, 108 unique exposure-outcome-population triplets (referred to as unique meta-analyses hereafter) of RCTs and 87 unique meta-analyses of observational studies were reanalyzed. Beneficial effects of folate were observed in the all-cause mortality rate and in a number of chronic diseases, including several birth/pregnancy outcomes, several cancers, cardiovascular disease and metabolic-related outcomes, neurological conditions, and several other diseases. However, adverse effects of folate were observed for prostate cancer, colorectal adenomatous lesions, asthma or wheezing, and wheezing as an isolated symptom and depression. Conclusions: Current evidence allows for the conclusion that folate is associated with decreased risk of all-cause mortality and a wide range of chronic diseases. However, folate may be associated with an increased risk of prostate cancer. Further research is warranted to improve the certainty of the estimates.

The association between periconceptional folic acid supplementation and the risk of preterm birth: a population-based retrospective cohort study of 200,000 women in China

PURPOSE

The aim of this study was to examine the association between periconceptional folic acid (FA) supplementation and risk of preterm birth.

METHODS

We conducted a retrospective cohort study in women aged 18-49 who participated in the NFPHEP from 2010 to 2018, and had a singleton livebirth in 129 counties in southwest China. Participants were divided into four groups according to the time period starting FA use: no use, after the last menstrual period, at least 1-2 months before the last menstrual period, at least 3 months before the last menstrual period. The outcomes were preterm birth (gestation < 37 weeks) and early preterm birth (gestation < 34 weeks).

RESULTS

201,477 women were included and 191,809 (95.2%) had taken FA during periconception. Compared with women who did not take FA, women who started taking FA 1-2 months before their last menstrual period had a 15% lower risk of preterm birth (aOR = 0.85, 95% CI 0.79-0.92), and women who started taking FA at least 3 months before their last menstrual period had a 20% lower risk of preterm birth (aOR = 0.80, 95% CI 0.75-0.87), but women who started taking FA after their last menstrual period did not appear to reduce the risk of preterm birth.

CONCLUSIONS

In this study of 200,000 Chinese women, periconceptional supplementation with FA was associated with a lower risk of preterm birth. Women who started taking FA at least 3 months before their last menstrual period were more likely to reduce the risk of preterm birth.

Cervical elastography using E-cervix for prediction of preterm birth in singleton pregnancies with threatened preterm labor

Objective: E-Cervix™ (WS80A; Samsung, Seoul, Korea) elastography is a recent quantification tool to measure the stiffness of the cervix using strain elastography. The aim of this study was to evaluate the prediction performance of E-cervix for preterm birth in singleton gestation with threatened preterm labor (PTL).Methods: This was a cohort study of singleton pregnancies without prior preterm birth presenting to obstetrics triage for threatened PTL between 23 0/7 and 33 6/7 week who received screening for PTL with transvaginal ultrasound cervical length (TVU CL) and cervical elastography with E-cervix at the time of triage. Cervical elastography parameters were examined and compared between women who delivered preterm and those who did not. The quantification of cervical strain was calculated by a data analysis system that directly analyses raw data from the region of interest (ROI) and described as hardness ratio (HR), mean strain level within 1 cm from internal os (IOS) and external os (EOS).Results: Ninety-five singleton pregnancies without prior preterm birth and with threatened PTL between 23 0/7 and 33 6/7 week of gestation were included in the study. Forty-two (44.2%) had cervical length <25 mm, and were admitted for true PLT. Out of the 53 women with cervical length ≥25 mm, 40 (75.5%) were discharged, and 13 (24.5%) were admitted. Women with threatened PTL but without true PTL, had significantly higher HR compared to those with true PTL (49.0 ± 20.9% versus 34.8 ± 19.6%; p < .01), and significantly lower stiffness of cervical IOS and EOS. Women who delivered preterm had significantly lower HR compared to those who did not delivery preterm, in overall cohort, and in the subset of only women with true PTL. Incidences of HR < 50% and <35% were statistically significantly higher in women who delivered preterm compared to those who did not (p < .01).Conclusions: Cervical elastography with E-cervix may be useful for the assessment of women presenting to obstetrics triage for threatened PTL. Women with low HR, especially with HR less than 50 or 35%, are at increased risk of PTB.Condensation: Women who delivered preterm had significantly lower HR compared to those who did not delivery preterm and significantly lower IOS and EOS, in overall cohort, and in the subset of women with true PTL. Incidences of HR < 50% and <35% were statistically significantly higher in women who delivered preterm compared to those who did not (p < .01).Key message: Cervical elastography with E-cervix may be useful for the assessment of women presenting to obstetrics triage for threatened PTL.

Folic Acid and Risk of Preterm Birth: A Meta-Analysis

The results from epidemiologic studies linking blood folate concentrations, folic acid supplementation, or dietary folate to the risk of preterm birth are inconsistent. In this study, we aimed to summarize the available evidence on these associations. A systematic search of the PubMed/MEDLINE, Google Scholar, Web of Science, and Cochrane Library databases up to October 20, 2018 was performed and reference lists of retrieved articles were screened. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the highest vs. the lowest levels of folate concentrations, folic acid supplementation, and dietary folate were calculated using random-effects models. Subgroup analyses and univariate meta-regression were performed to explore the sources of heterogeneity. Ten studies (six prospective cohort studies and four case-control studies) were included on folate concentrations, 13 cohort studies were included about folic acid supplementation, and 4 cohort studies were included regarding dietary folate intake. Higher maternal folate levels were associated with a 28% reduction in the risk of preterm birth (OR 0.72, 95% CI 0.56–0.93). Higher folic acid supplementation was associated with 10% lower risk of preterm birth (OR 0.90, 95% CI 0.85–0.95). In addition, a significant negative association was observed between dietary folate intake and the risk of preterm birth (OR 0.68, 95% CI 0.55–0.84), but no significant relation was seen between dietary folate and the risk of spontaneous preterm birth (OR 0.89, 95% CI 0.57–1.41). In the subgroup analysis, higher maternal folate levels in the third trimester were associated with a lower risk of preterm birth (OR 0.58, 95% CI 0.36–0.94). To initiate taking folic acid supplementation early before conception was adversely associated with preterm birth risk (OR 0.89, 95% CI 0.83–0.95). In conclusion, higher maternal folate levels and folic acid supplementation were significantly associated with a lower risk of preterm birth. The limited data currently available suggest that dietary folate is associated with a significantly decreased risk of preterm birth.

An investigation of vitamin and mineral supplement recommendation among first-trimester pregnancies

Background Healthy and balanced nutrition in pregnancy can affect the mother's and the fetus' health. Therefore, health professionals should provide information about this issue to pregnant women. The aim of the study was to examine the rate of vitamin and mineral supplement recommendation among first-trimester pregnant women. Methods The study sample consisted of 697 first-trimester pregnant women between 18 and 40 years of age. The pregnant women who registered to an obstetric outpatient clinic between January and June 2018 were retrospectively reviewed, and data were collected from patient medical records using a questionnaire. Results Physician's laboratory test orders from the women included the following: ferritin was 18.4%, mean corpuscular hemoglobin (MCH) was 99.7%, folic acid was 10.2%, vitamin D was 6.3%, vitamin B12 was 17.2% and calcium was 20.4%. All of the women's hemoglobin levels had been examined. A total of 58.8% of the women were recommended to take folic acid, 32.7% iron, 25.7% iodine, 18.8% calcium, 17.2% vitamin A, 21.1% vitamin B12, 17.4% vitamin C, 31.6% vitamin D and 17.5% vitamin E supplements. Conclusion It was determined that ferritin, vitamins B12 and D, calcium, folic acid, iron and iodine levels were not examined routinely in this study. Folic acid and iron supplementation were the most commonly suggested nutrient supplements in the first trimester.

Evaluation of folate concentration in amniotic fluid and maternal and umbilical cord blood during labor

INTRODUCTION

Folate is required for fetal, placental and maternal tissue growth during pregnancy. A decline in maternal circulating folate concentrations and an increase in total homocysteine (a non-specific indicator of folate deficiency) have been observed with the progression of pregnancy. However, the role of folate in the third trimester of pregnancy is not clear and folate status in late pregnancy has not so far been widely analyzed. The main aim of this retrospective cross-sectional study was to determine the folate concentrations in amniotic fluid and in maternal and umbilical cord blood serum derived during delivery.

MATERIAL AND METHODS

This study was conducted on 175 pregnant Polish women (white/Caucasian) aged between 17 and 42 years. Only pregnancies without birth defects were included in this study. Amniotic fluid, maternal serum, and umbilical cord blood samples were collected during vaginal delivery or cesarean section. Folate concentration was determined using a microbiological assay.

RESULTS

Strong correlations were observed between the concentrations of folate in amniotic fluid and maternal serum (rho = 0.67, p < 0.001) and amniotic fluid and cord blood serum (rho = 0.49, p < 0.001) and between maternal serum and cord blood serum (rho = 0.67, p < 0.001). Folate concentrations in amniotic fluid were significantly associated with maternal age (rho = 0.19, p < 0.05). Pre-pregnancy body mass index and maternal weight/neonatal birth weight ratio were independent predictors of folate concentrations in maternal serum (β = 0.33, p < 0.05; β = -0.19, p < 0.05) and amniotic fluid (β = 0.28, p < 0.05; β = -0.19, p < 0.05) in late pregnancy.

CONCLUSIONS

Folate concentrations in amniotic fluid are associated with maternal and neonatal folate status peripartum in healthy women.

Effects of progestogens in women with preterm premature rupture of membranes

Different strategies have been adopted for prevention of spontaneous preterm birth, including use of progestogens. So far, five randomized trials have been published evaluating the efficacy of progestogens in women with PPROM, including a total of 425 participants. All the five trials enrolled pregnant women with singleton pregnancies randomized between 20 and 34 weeks of gestation. In four trials women were randomized to either weekly intramuscular 250 mg 17α-hydroxyprogesterone-caproate or placebo, while Mirzaei et al. was a three arms trials in which women received weekly intramuscular 250 mg 17α-hydroxyprogesterone-caproate, or rectal progesterone 400 mg daily, or no treatment. In all the trials, latency antibiotics were used, and tocolysis was used permitted for first 48 hours at discretion of attending physician. Recently a meta-analysis including the five trials has been published. They found that when compared to placebo weekly intramuscular 250 mg 17α-hydroxyprogesterone-caproate did not alter the latency period to delivery in singleton gestations with PPROM. Additionally, there was no difference in gestational age at delivery between groups or in mode of delivery. No significant differences were reported in maternal or neonatal outcomes, with latency not significantly altered in sensitivity analyses. So far, no trials have been published evaluating natural vaginal progesterone in women with PPROM.

Effects of exercise during pregnancy in women with short cervix: Secondary analysis from the Italian Pessary Trial in singletons

OBJECTIVE

To evaluate effects of exercise during pregnancy in asymptomatic singleton pregnancies without prior spontaneous preterm birth (SPTB) but with short transvaginal ultrasound cervical length (TVU CL).

STUDY DESIGN

This is a secondary analysis of the Italian Pessary Trial for the Italian Preterm Birth Prevention (IPP) Working Group. In the original prospective randomized controlled trial asymptomatic singleton pregnancies without prior SPTB but with TVU CL ≤ 25 mm at 18 0/6-23 6/7 weeks were randomized into 1:1 ratio to either cervical pessary or no pessary. During their follow-up visits, women were asked about their activity. For the purpose of this secondary analysis, women were classified in the following groups, using the information obtained in the follow-up visit one month after randomization: 1) Exercise group, defined as women performing exercise ≥2 days a week for ≥20 min each day. 2) No exercise group, defined as women performing exercise <2 days a week for ≥20 min each day. The primary outcome of this secondary analysis was PTB < 37 weeks.

RESULTS

300 women were included in this analysis. 99 (33.0%) were included in the exercise group. 201 (67.0%) were included in the no exercise group. Of the 201 women in the no exercise group, 90 (44.8%) affirmed that they had reduced their activity after the diagnosis of short cervix despite the research staff recommendations, while the other 111 (55.2%) women performed a sedentary life style even before the diagnosis of short cervix. PTB < 37 weeks occurred in 22 women (22.2%) in the exercise group, and 66 women (32.8%) in the no exercise group (aOR 0.65, 95% CI 0.33-1.03).

CONCLUSION

In asymptomatic singleton pregnancies with short cervix, performing exercise ≥2 days a week for ≥20 min each day does not increase the risk of PTB but is indeed associated with a non-significant reduction in PTB < 37 weeks by 32%.

Midtrimester transvaginal ultrasound cervical length screening for spontaneous preterm birth in diamniotic twin pregnancies according to chorionicity

OBJECTIVE

To compare the mean transvaginal ultrasound (TVU) cervical length (CL) at midtrimester screening for spontaneous preterm birth in asymptomatic monochorionic diamniotic versus dichorionic diamniotic twin pregnancies STUDY DESIGN: This was a multicenter retrospective cohort study. Study subjects were identified at the time of a routine second trimester fetal ultrasound exam at 18 0/7-23 6/7 weeks gestation. We excluded women that received progesterone, pessary, or cerclage. Distribution of CL was determined and normality was examined. Mean of TVU CL were compared between monochorionic diamniotic and dichorionic diamniotic pregnancies. The relationship of TVU CL with gestational age (GA) at delivery and incidence of spontaneous preterm birth (SPTB) at different TVU CL cut offs were assessed. Incidence of short TVU CL, defined as TVU CL ≤30 mm, was also calculated in the two groups.

RESULTS

580 women with diamniotic twin pregnancies underwent TVU CL screening between 18 0/6 and 23 6/7 weeks. 175 (30.2%) were monochorionic diamniotic pregnancies, and 405 (69.8%) were dichorionic pregnancies. The demographic characteristics were similar on both groups. The mean GA at TVU CL was about 20 week in both groups. The mean TVU CL was significantly lower in the monochorionic diamniotic (32.8 ± 10.1) compared to the dichorionic (34.9 ± 8.6) group (MD -2.10 mm, 95% CI -3.91 to -0.29). TVU CL ≤30 mm was 16.6% (29/175) in the monochorionic group, and 11.9% (48/405) in the dichorionic group (aOR 1.48, 95% CI 1.03-2.43). Twins with a monochorionic diamniotic pregnancy had a significantly higher incidence of SPTB (53.1% vs 44.9%; aOR 1.22, 95% CI 1.22-1.79). For any given CL measured between 18 0-7 and 23 6/7 weeks, gestational age at delivery for monochorionic diamniotic pregnancies was about 2 weeks earlier compared to dichorionic pregnancies (MD -2.1 weeks; ANCOVA P < 0.001).

CONCLUSION

Monochorionic diamniotic twin pregnancies had a higher rate of spontaneous preterm birth than dichorionic diamniotic pregnancies. The higher rate of spontaneous preterm delivery in monochorionic pregnancies is associated with lower midtrimester TVU CL when compared to dichorionic pregnancies.

Decrease in the incidence of threatened preterm labor after implementation of transvaginal ultrasound cervical length universal screening

BACKGROUND

It is unknown if universal second-trimester transvaginal ultrasound (TVU) cervical length (CL) screening in asymptomatic women with singleton gestations and no prior spontaneous preterm birth (SPTB) affects the incidence of symptoms of preterm labor (PTL) later in pregnancy.

OBJECTIVE

To evaluate the incidence of threatened PTL before and after the implementation of universal second trimester TVU CL screening.

STUDY DESIGN

This was a retrospective cohort study of all consecutive singleton gestations without prior SPTB presenting to obstetric triage for threatened PTL between 23 0/7 and 33 6/7 week in 2011 (1 January-31 December), and in 2014 (1 January-31 December) at Thomas Jefferson University Hospital (TJU) (Philadelphia, PA). These 2 years were chosen as a new protocol for universal TVU CL screening was started on 1 January 2012. This protocol involved one measurement of TVU CL in all singleton gestations without a prior SPTB at 18 0/7 - 23 6/7 week, the time of the "anatomy" scan. Women with prior SPTB were excluded from this study. The primary outcome included the incidence of threatened PTL, defined as the number of women with singleton gestations without prior SPTB who presented with threatened PTL to our labor and delivery (L&D) triage unit annually, divided by the total number of annual deliveries of women with singleton gestation without prior SPTB. Secondary outcomes were the incidence of PTL, defined as the number of women with singleton gestations without prior SPTB admitted for PTL annually divided by the total number of annual deliveries of women with singleton gestation and without prior SPTB; and length of stay in the hospital. We aimed to compare primary and secondary outcome in the "2011" versus the "2014" group.

RESULTS

In 2011, there were a total of 1745 deliveries at TJU, of which 1550 (88.8%) were singletons without prior SPTB. In 2014, there were a total of 1924 deliveries at TJU, 1751 (91.0%) were singletons without prior SPTB who were offered universal TVU CL screening. One hundred and seventy-two women with singletons without prior SPTB presented in L&D triage unit in 2011; and 118 women with singletons without prior SPTB presented in L&D triage unit in 2014. There were significant decreases in the incidence of threatened PTL from 11.1% (172/1550) in 2011 to 6.7% (118/1751) in 2014 (p < .001), as well as in the rate of admission for PTL from 2.3% (35/1550) to 1.4% (24/1751), respectively (p = .04). Length of stay was not significantly different between the two groups.

CONCLUSION

The introduction of a universal TVU CL screening program in women with singleton gestations without a history of SPTB is associated with a reduction in the frequency of threatened PTL and admission for PTL. Key Message The introduction of a second trimester universal transvaginal ultrasound (TVU) cervical length (CL) screening program in women without a history of spontaneous preterm birth (SPTB) is associated with a reduction in the incidence of threatened preterm labor (PTL) and admission for PTL.

Effect of Cervical Pessary on Spontaneous Preterm Birth in Women With Singleton Pregnancies and Short Cervical Length: A Randomized Clinical Trial

IMPORTANCE

Spontaneous preterm birth is a major cause of perinatal morbidity and mortality. It is unclear if a cervical pessary can reduce the risk of spontaneous preterm delivery.

OBJECTIVE

To test whether in asymptomatic women with singleton pregnancies and no prior spontaneous preterm birth but with short cervical length on transvaginal ultrasound, use of a cervical pessary would reduce the rate of spontaneous preterm birth at less than 34 weeks of gestation.

DESIGN, SETTING, AND PARTICIPANTS

Parallel-group, nonblinded, randomized clinical trial conducted from March 1, 2016, to May 25, 2017, at a single center in Italy. Asymptomatic women with singleton gestations, no previous spontaneous preterm births, and cervical lengths of 25 mm or less at 18 weeks 0 days to 23 weeks 6 days of gestation were eligible.

INTERVENTIONS

Patients were randomized 1:1 to receive either cervical pessary (n = 150) or no pessary (n = 150). The pessary was removed between 37 weeks 0 days and 37 weeks 6 days of gestation or earlier if clinically indicated. The control group received standard care. For cervical length of 20 mm or shorter, women in both groups were prescribed vaginal progesterone, 200 mg/d, until 36 weeks 6 days of gestation. No bed rest or activity restriction was recommended.

MAIN OUTCOMES AND MEASURES

The primary end point was spontaneous preterm birth at less than 34 weeks of gestation. Secondary outcomes were adverse events.

RESULTS

Among 300 women who were randomized (mean age, 29 [SD, 6.3] years; mean gestational age, 22 [SD, 1.3] weeks), 100% completed the trial. The primary end point occurred in 11 women (7.3%) in the pessary group and 23 women (15.3%) in the control group (between-group difference, -8.0% [95% CI, -15.7% to -0.4]; relative risk, 0.48 [95% CI, 0.24-0.95]). During follow-up, the pessary group had a higher rate of increased or new vaginal discharge (86.7% vs 46.0%; between-group difference, +40.7% [95% CI, +30.1%-+50.3%]; relative risk, 1.88 [95% CI, 1.57-2.27]).

CONCLUSIONS AND RELEVANCE

Among women without prior spontaneous preterm birth who had asymptomatic singleton pregnancies and short transvaginal cervical length, use of a cervical pessary, compared with no pessary use, resulted in a lower rate of spontaneous preterm birth at less than 34 weeks of gestation. The results of this single-center, nonblinded study among selected pregnant women require confirmation in multicenter clinical trials.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02716909.

Folic acid level and preterm birth among Sudanese women

BACKGROUND

Preterm birth (PTB) is the major health problem world-wide; there are few published studies on PTB and folic acid.

METHODS

The study was conducted to assess the serum level of folic acid in PTB. A case-control study was conducted at Saad Abualila maternity hospital (Khartoum, Sudan) during the period of March through December 2015. Women who delivered live singleton babies were dived in two groups; the cases were women who had PTB "delivery before completed 37weeks but after 24 weeks of pregnancy" and the controls were women who delivered at term (37-42 weeks). Medical and obstetrics history was gathered using questionnaire. Serum folic acid was measured.

RESULTS

One hundred and twelve (56 in arm of the study) women were enrolled to the study. There was no significant difference between the cases and the controls in their age, parity, hemoglobin, body mass index, education and occupation. The median (interquartile) level of folic acid was significantly lower in the cases (PTB) than the level in the controls, 4.8(2.8-8.2) vs. 9.5(8.6-12.0) ng/ml. In binary regression, folic acid level was associated with lower risk of PTB (OR=0.64; 95%=0.53-0.77, P < 0.001). There was a significant positive correlation between gestational age and folic acid level (r = 0.447, P<0.001).

CONCLUSION

Thus serum folic acid level was significantly lower in women with PTB. Folic acid level was associated with lower risk of PTB.

Cerclage for sonographic short cervix in singleton gestations without prior spontaneous preterm birth: systematic review and meta-analysis of randomized controlled trials using individual patient-level data

OBJECTIVE

The aim of this systematic review and meta-analysis was to quantify the efficacy of cervical cerclage in preventing preterm birth (PTB) in asymptomatic singleton pregnancies with a short mid-trimester cervical length (CL) on transvaginal sonography (TVS) and without prior spontaneous PTB.

METHODS

Electronic databases were searched from inception of each database until February 2017. No language restrictions were applied. All randomized controlled trials (RCTs) of asymptomatic singleton pregnancies without prior spontaneous PTB, found to have short CL < 25 mm on mid-trimester TVS and then randomized to management with either cerclage or no cerclage, were included. Corresponding authors of all the included trials were contacted to obtain access to the data and perform a meta-analysis of individual patient-level data. Data provided by the investigators were merged into a master database constructed specifically for the review. Primary outcome was PTB < 35 weeks. Summary measures were reported as relative risk (RR) with 95% CI. The quality of the evidence was assessed using the GRADE approach.

RESULTS

Five RCTs, including 419 asymptomatic singleton gestations with TVS-CL < 25 mm and without prior spontaneous PTB, were analyzed. In women who were randomized to the cerclage group compared with those in the control group, no statistically significant differences were found in PTB < 35 (21.9% vs 27.7%; RR, 0.88 (95% CI 0.63-1.23); I²  = 0%; five studies, 419 participants), < 34, < 32, < 28 and < 24 weeks, gestational age at delivery, preterm prelabor rupture of membranes (PPROM) and neonatal outcomes. In women who received cerclage compared with those who did not, planned subgroup analyses revealed a significantly lower rate of PTB < 35 weeks in women with TVS-CL < 10 mm (39.5% vs 58.0%; RR, 0.68 (95% CI, 0.47-0.98); I²  = 0%; five studies; 126 participants) and in women who received tocolytics (17.5% vs 32.7%; RR, 0.54 (95% CI, 0.31-0.93); I²  = 0%; four studies; 169 participants) or antibiotics (18.3% vs 31.5%; RR, 0.58 (95% CI, 0.33-0.98); I²  = 0%; three studies; 163 participants) as additional therapy to cerclage. The quality of evidence was downgraded two levels because of serious imprecision and indirectness, and therefore was judged as low.

CONCLUSIONS

In singleton gestations without prior spontaneous PTB but with TVS-CL < 25 mm in the second trimester, cerclage does not seem to prevent preterm delivery or improve neonatal outcome. However, in these pregnancies, cerclage seems to be efficacious at lower CLs, such as < 10 mm, and when tocolytics or antibiotics are used as additional therapy, requiring further studies in these subgroups. Given the low quality of evidence, further well-designed RCTs are needed to confirm the findings of this study. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Cervical Pessary for Preventing Preterm Birth in Singleton Pregnancies With Short Cervical Length: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of cervical pessary for preventing spontaneous preterm birth (SPTB) in singleton gestations with a second trimester short cervix.

METHODS

Electronic databases were searched from their inception until February 2016. We included randomized clinical trials (RCTs) comparing the use of the cervical pessary with expectant management in singletons pregnancies with transvaginal ultrasound cervical length (TVU CL) ≤25 mm. The primary outcome was incidence of SPTB <34 weeks. The summary measures were reported as relative risk (RR) with 95% confidence interval (CI).

RESULTS

Three RCTs (n = 1,420) were included. The mean gestational age (GA) at randomization was approximately 22 weeks. The Arabin pessary was used as intervention in all three trials, and was removed by vaginal examination at approximately 37 weeks. Cervical pessary was not associated with prevention of SPTB <37 (20.2% vs 50.2%; RR 0.50, 95% CI 0.23 to 1.09), <34, <32, and <28 weeks, compared to no pessary. No differences were found in the mean of GA at, interval from randomization to delivery, incidence of preterm premature rupture of membranes and of cesarean delivery, and in neonatal outcomes. The Arabin pessary was associated with a significantly higher risk of vaginal discharge.

CONCLUSIONS

In singleton pregnancies with a TVU CL ≤25mm at 20⁰ -24⁶ weeks, the Arabin pessary does not reduce the rate of spontaneous preterm delivery or improve perinatal outcome. Individual patient data meta-analysis may clarify whether cervical pessary may be beneficial in subgroups, such as only singleton gestations without prior SPTB or by different CL cutoffs.

Interventions for treating hyperemesis gravidarum: a Cochrane systematic review and meta-analysis

INTRODUCTION

While nausea and vomiting in early pregnancy are very common, affecting approximately 80% of the pregnancies, hyperemesis gravidarum is a severe form affecting 0.3-1.0% of the pregnancies. Although hyperemesis gravidarum is rarely a source of mortality, it is a significant source of morbidity. It is one of the most common indications for hospitalization in pregnancy. Beyond the maternal and fetal consequences of malnutrition, the severity of hyperemesis symptoms causes a major psychosocial burden leading to depression, anxiety, and even pregnancy termination. The aim of this meta-analysis was to examine all randomized controlled trials of interventions specifically for hyperemesis gravidarum and evaluate them based on both subjective and objective measures of efficacy, maternal and fetal/neonatal safety, and economic costs.

MATERIAL AND METHODS

Randomized controlled trials were identified by searching electronic databases. We included all randomized controlled trials for the treatment of hyperemesis gravidarum. The primary outcome was intervention efficacy as defined by severity, reduction, or cessation in nausea/vomiting; number of episodes of emesis; and days of hospital admission. Secondary outcomes included other measures of intervention efficacy, adverse maternal/fetal/neonatal outcomes, quality of life measures, and economic costs.

RESULTS

Twenty-five trials (2052 women) met the inclusion criteria but the majority of 18 different comparisons described in the review include data from single studies with small numbers of participants. Selected comparisons reported below: No primary outcome data were available when acupuncture was compared with placebo. There was insufficient evidence to identify clear differences between acupuncture and metoclopramide in a study with 81 participants regarding reduction/cessation in nausea or vomiting (risk ratio (RR) 1.40, 95% CI 0.79-2.49 and RR 1.51, 95% CI 0.92-2.48, respectively). Midwife-led outpatient care was associated with fewer hours of hospital admission than routine inpatient admission (mean difference (MD) - 33.20, 95% CI -46.91 to -19.49) with no difference in pregnancy-unique quantification of emesis and nausea (PUQE) score, decision to terminate the pregnancy, miscarriage, small-for-gestational age infants, or time off work when compared with routine care. Women taking vitamin B6 had a slightly longer hospital stay compared with placebo (MD 0.80 days, 95% CI 0.08-1.52). There was insufficient evidence to demonstrate a difference in other outcomes including mean number of episodes of emesis (MD 0.50, 95% CI -0.40-1.40) or side effects. A comparison between metoclopramide and ondansetron identified no clear difference in the severity of nausea or vomiting (MD 1.70, 95% CI -0.15-3.55, and MD -0.10, 95% CI -1.63-1.43; one study, 83 women, respectively). However, more women taking metoclopramide complained of drowsiness and dry mouth (RR 2.40, 95% CI 1.23-4.69, and RR 2.38, 95% CI 1.10-5.11, respectively). There were no clear differences between groups for other side effects. In a single study with 146 participants comparing metoclopramide with promethazine, more women taking promethazine reported drowsiness, dizziness, and dystonia (risk ratio (RR) 0.70, 95% CI 0.56-0.87, RR 0.48, 95% CI 0.34-0.69, and RR 0.31, 95% CI 0.11-0.90, respectively). There were no clear differences between groups for other important outcomes including quality of life and other side effects. In a single trial with 30 women, those receiving ondansetron had no difference in duration of hospital admission compared to those receiving promethazine (mean difference (MD) 0.00, 95% CI -1.39-1.39), although there was increased sedation with promethazine (RR 0.06, 95% CI 0.00-0.94). Regarding corticosteroids, in a study with 110 participants there was no difference in days of hospital admission compared to placebo (MD -0.30, 95% CI -0.70-0.10), but there was a decreased readmission rate (RR 0.69, 95% CI 0.50-0.94; 4 studies, 269 women). For hydrocortisone compared with metoclopramide, no data were available for primary outcomes and there was no difference in the readmission rate (RR 0.08, 95% CI 0.00-1.28; one study, 40 women). In a study with 80 women, compared to promethazine, those receiving prednisolone had increased nausea at 48 h (RR 2.00, 95% CI 1.08-3.72), but not at 17 days (RR 0.81, 95% CI 0.58-1.15). There was no clear difference in the number of episodes of emesis or subjective improvement in nausea/vomiting.

CONCLUSIONS

While there were a wide range of interventions studied, both pharmaceutical and otherwise, there were a limited number of placebo controlled trials. In comparing the efficacy of the commonly used antiemetics, metoclopramide, ondansetron, and promethazine, the results of this review do not support the clear superiority of one over the other in symptomatic relief. Other factors such as side effect profile medication safety and healthcare costs should also be considered when selecting an intervention.

Folate, vitamin B12, ferritin and haemoglobin levels among women of childbearing age from a rural district in South India

Background

Low folate and vitamin B12 levels have negative effect on pregnancy outcomes but there is paucity of data on their levels among Indian women. Ferritin and haemoglobin are associated with maternal mortality and low birth-weight. Our aim was to estimate the prevalence of deficiency of serum folate and vitamin B12, and low levels of serum ferritin and blood haemoglobin among women of childbearing age from a rural population of South India.

Methods

We conducted a community-based cross-sectional study among 15-35 year women in a rural district. We used multistage stratified random sampling. Trained staff interviewed women to collect socio-demographic information and draw blood samples. We analysed samples for serum folate, vitamin B12, ferritin and blood haemoglobin levels and computed means and medians. We computed the proportion of deficiency based on cut-offs recommended by WHO. We examined the association of levels with age, parity and current pregnancy or breastfeeding by multi-variable regression using Stata 13.0.

Results

We recruited 979 women. One-fifth (185, 19%) were pregnant and one-fifth (196, 20%)were breastfeeding. Median serum folate levels were 2.5 ng/ml (IQR, 1.2-4.8), median vitamin B12 levels were 228.0 pg/ml (IQR, 121 - 390), median ferritin levels were 13.0 μg/l (IQR, 6.0 - 20.0) and median blood haemoglobin levels were 12.1 mg/dl (IQR, 10.7 – 13.6). Low levels of serum folate, vitamin B12, ferritin and haemoglobin were found in 57% (95% CI, 54-60%), 44% (95% CI, 41-48%), 46% (95% CI, 43-49%) and 28% (95% CI, 25-31%) respectively. Women with folic acid deficiency had two times higher prevalence of having vitamin B12 deficiency. In adjusted regression analysis folate levels were lower in older and breastfeeding women, but not associated with parity and were higher among pregnant women. Similar associations were not found with Vitamin B12 deficiency. Ferritin levels were higher in older women; but not associated with parity, pregnancy or breastfeeding. Haemoglobin levels were lower in pregnant and breastfeeding women.

Conclusion

Our findings suggest that folic acid, vitamin B12 and iron deficiency are important public health problems in India. We observed that half of the women of childbearing age were deficient in these nutrients. Folic acid and vitamin B12 deficiencies co-exist and should be supplemented together.