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The Journal of Obstetrics and... Aug 2021Postpartum hemorrhage (PPH) has remained the leading cause of maternal mortality. While anemia is a leading contributor to maternal morbidity, molecular, cellular and... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Postpartum hemorrhage (PPH) has remained the leading cause of maternal mortality. While anemia is a leading contributor to maternal morbidity, molecular, cellular and anemia-induced hypoxia, clinical studies of the relationship between prenatal-anemia and PPH have reported conflicting results. Therefore, our objective was to investigate the outcomes of studies on the relationships between prenatal anemia and PPH-related mortality.
MATERIALS AND METHODS
Electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE, and the Cochrane Central Register of Controlled Trials) were searched for studies published before August 2019. Keywords included "anemia," "hemoglobin," "postpartum hemorrhage," and "postpartum bleeding." Only studies involving the association between anemia and PPH were included in the meta-analysis. Our primary analysis used random effects models to synthesize odds-ratios (ORs) extracted from the studies. Heterogeneity was formally assessed with the Higgins' I statistics, and explored using meta-regression and subgroup analysis.
RESULTS
We found 13 eligible studies investigating the relationship between prenatal anemia and PPH. Our findings suggest that severe prenatal anemia increases PPH risk (OR = 3.54; 95% CI: 1.20, 10.4, p-value = 0.020). There was no statistical association with mild (OR = 0.60; 95% CI: 0.31, 1.17, p-value = 0.130), or moderate anemia (OR = 2.09; 95% CI: 0.40, 11.1, p-value = 0.390) and the risk of PPH.
CONCLUSION
Severe prenatal anemia is an important predictive factor of adverse outcomes, warranting intensive management during pregnancy. PROSPERO Registration Number: CRD42020149184; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=149184.
Topics: Anemia; Female; Humans; Maternal Mortality; Oxytocics; Postpartum Hemorrhage; Postpartum Period; Pregnancy
PubMed: 34002432
DOI: 10.1111/jog.14834 -
Health & Place Nov 2022In the United States, racial disparities in adverse maternal health outcomes remain a pressing issue, with Black women experiencing a 3-4 times higher risk of maternal... (Review)
Review
In the United States, racial disparities in adverse maternal health outcomes remain a pressing issue, with Black women experiencing a 3-4 times higher risk of maternal mortality and a 2-3 times higher risk of severe maternal morbidity. Despite recent encouraging efforts, fundamental determinants of these alarming inequities (e.g. structural racism) remain understudied. Approaches that address these structural drivers are needed to then intervene upon root causes of adverse maternal outcomes and their disparities and to ultimately improve maternal health across the U.S. In this paper, we offer a conceptual framework for studies of structural racism and maternal health disparities and systematically synthesize the current empirical epidemiologic literature on the links between structural racism measures and adverse maternal health outcomes. For the systematic review, we searched electronic databases (Pubmed, Web of Science, and EMBASE) to identify peer-reviewed U.S. based quantitative articles published between 1990 and 2021 that assessed the link between measures of structural racism and indicators of maternal morbidity/mortality. Our search yielded 2394 studies and after removing duplicates, 1408 were included in the title and abstract screening, of which 18 were included in the full text screening. Only 6 studies met all the specified inclusion criteria for this review. Results revealed that depending on population sub-group analyzed, measures used, and covariates considered, there was evidence that structural racism may increase the risk of adverse maternal health outcomes. This review also highlighted several areas for methodological and theoretical development in this body of work. Future work should more comprehensively assess structural racism in a way that informs policy and interventions, which can ameliorate its negative consequences on racial/ethnic disparities in maternal morbidity/mortality.
Topics: Humans; Female; Maternal Health; Systemic Racism; Black People; Databases, Factual; Ethnicity
PubMed: 36401939
DOI: 10.1016/j.healthplace.2022.102923 -
Tropical Medicine & International... Jul 2022Given that women of reproductive age in dengue-endemic areas are at risk of infection, it is necessary to determine whether dengue virus (DENV) infection during... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Given that women of reproductive age in dengue-endemic areas are at risk of infection, it is necessary to determine whether dengue virus (DENV) infection during pregnancy is associated with adverse outcomes. The aim of this systematic review and meta-analysis is to investigate the consequences of DENV infection in pregnancy on various maternal and foetal-neonatal outcomes.
METHODS
A systematic literature search was undertaken using PubMed, Google Scholar, and Embase till December 2021. Mantel-Haenszel risk ratios were calculated to report overall effect size using random effect models. The pooled prevalence was computed using the random effect model. All statistical analyses were performed on MedCalc Software.
RESULT
We obtained data from 36 studies involving 39,632 DENV-infected pregnant women. DENV infection in pregnancy was associated with an increased risk of maternal mortality (OR = 4.14 [95% CI, 1.17-14.73]), stillbirth (OR = 2.71 [95% CI, 1.44-5.10]), and neonatal deaths (OR = 3.03 [95% CI, 1.17-7.83]) compared with pregnant women without DENV infection. There was no significant statistical association established between maternal DENV infection and the outcomes of preterm birth, maternal bleeding, low birth weight in neonates, and risk of miscarriage. Pooled prevalences were 14.9% for dengue shock syndrome, 14% for preterm birth, 13.8% for maternal bleeding, 10.1% for low birth weight, 6% for miscarriages, and 5.6% for stillbirth.
CONCLUSION
DENV infection in pregnant women may be associated with adverse outcomes such as maternal mortality, stillbirth, and neonatal mortality. Hence, pregnant women should be considered an at-risk population for dengue management programmes.
Topics: Abortion, Spontaneous; Dengue; Female; Humans; Infant; Infant Mortality; Infant, Newborn; Maternal Mortality; Pregnancy; Pregnancy Complications, Infectious; Pregnancy Outcome; Premature Birth; Stillbirth
PubMed: 35689528
DOI: 10.1111/tmi.13783 -
International Journal of Gynaecology... Oct 2022To evaluate the risk levels for maternal and perinatal complications at > 40, > 45 and > 50 years old compared with younger controls. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To evaluate the risk levels for maternal and perinatal complications at > 40, > 45 and > 50 years old compared with younger controls.
METHODS
Electronic databases were searched from their inception until March 2021. We included studies reporting pregnancy outcome in pregnant women aged 40, 45, and 50 years or older compared with controls at the time of delivery. Case reports and case series were excluded. The primary outcome was the incidence of stillbirth. Meta-analysis was performed using the random effects model of DerSimonian and Laird, to produce summary treatment effects in terms of relative risk (RR) with 95% confidence interval (CI). Heterogeneity was measured using I (Higgins I ). Subgroup analyses in women older than 45 years and in those older than 50 years were performed.
RESULTS
Twenty-seven studies, including 31 090 631 women, were included in the meta-analysis. The overall quality of the included studies was moderate to high. Most of the included studies were retrospective cohort studies (21/27), four were population-based studies, and two were cross-sectional studies. Women aged ≥40 years had significantly higher risk of stillbirth (RR 2.16, 95% CI 1.86-2.51), perinatal mortality, intrauterine growth restriction, neonatal death, admission to neonatal intensive care unit, pre-eclampsia, preterm delivery, cesarean delivery, and maternal mortality compared with women younger than 40 years old (RR 3.18, 95% CI 1.68-5.98). The increased risks for maternal mortality were 42.76 and 11.60 for women older than 50 years and for those older than 45 years, respectively, whereas those for stillbirth were 3.72 and 2.32. The risk of stillbirth and cesarean delivery was significantly higher in women >45 years compared with those aged 40-45 years, and in those aged >50 years compared with those aged 45-50 years. The risk of maternal mortality was significantly higher in women aged >50 years compared with those aged 40-45 (RR 60.40, 95% CI 13.28-274.74).
CONCLUSION
The risk of stillbirth, cesarean delivery, and maternal mortality increases with advancing maternal age. The risk ratios for maternal mortality were 3.18, 11.60, and 42.76 in women older than 40, older than 45, and older than 50 years, respectively. These data should be used when women with advanced maternal age are counseled regarding their risk in pregnancy.
SYSTEMATIC REVIEW REGISTRATION
The review was registered with the PROSPERO International Prospective Register of Systematic Reviews (registration No.: CRD42020208788).
Topics: Adult; Female; Humans; Infant, Newborn; Maternal Age; Middle Aged; Perinatal Death; Pregnancy; Pregnancy Outcome; Premature Birth; Retrospective Studies; Stillbirth
PubMed: 35044694
DOI: 10.1002/ijgo.14100 -
American Journal of Perinatology Aug 2017Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. We searched PubMed, EMBASE, Web of... (Review)
Review
Risk factors for placental abruption have changed, but there has not been an updated systematic review investigating outcomes. We searched PubMed, EMBASE, Web of Science, SCOPUS, and CINAHL for publications from January 1, 2005 through December 31, 2016. We reviewed English-language publications reporting estimated incidence and/or risk factors for maternal, labor, delivery, and perinatal outcomes associated with abruption. We excluded case studies, conference abstracts, and studies that lacked a referent/comparison group or did not clearly characterize placental abruption. A total of 123 studies were included. Abruption was associated with elevated risk of cesarean delivery, postpartum hemorrhage and transfusion, preterm birth, intrauterine growth restriction or low birth weight, perinatal mortality, and cerebral palsy. Additional maternal outcomes included relaparotomy, hysterectomy, sepsis, amniotic fluid embolism, venous thromboembolism, acute kidney injury, and maternal intensive care unit admission. Additional perinatal outcomes included acidosis, encephalopathy, severe respiratory disorders, necrotizing enterocolitis, acute kidney injury, need for resuscitation, chronic lung disease, infant death, and epilepsy. Few studies examined outcomes beyond the initial birth period, but there is evidence that both mother and child are at risk of additional adverse outcomes. There was also considerable variation in, or absence of, the reporting of abruption definitions.
Topics: Abruptio Placentae; Asphyxia Neonatorum; Blood Transfusion; Cerebral Palsy; Cesarean Section; Female; Fetal Growth Retardation; Humans; Hypoxia, Brain; Infant, Low Birth Weight; Infant, Newborn; Maternal Mortality; Perinatal Mortality; Postpartum Hemorrhage; Pregnancy; Premature Birth; Recurrence; Stillbirth
PubMed: 28329897
DOI: 10.1055/s-0037-1599149 -
PLoS Medicine Dec 2019Infection is an important, preventable cause of maternal morbidity, and pregnancy-related sepsis accounts for 11% of maternal deaths. However, frequency of maternal... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Infection is an important, preventable cause of maternal morbidity, and pregnancy-related sepsis accounts for 11% of maternal deaths. However, frequency of maternal infection is poorly described, and, to our knowledge, it remains the one major cause of maternal mortality without a systematic review of incidence. Our objective was to estimate the average global incidence of maternal peripartum infection.
METHODS AND FINDINGS
We searched Medline, EMBASE, Global Health, and five other databases from January 2005 to June 2016 (PROSPERO: CRD42017074591). Specific outcomes comprised chorioamnionitis in labour, puerperal endometritis, wound infection following cesarean section or perineal trauma, and sepsis occurring from onset of labour until 42 days postpartum. We assessed studies irrespective of language or study design. We excluded conference abstracts, studies of high-risk women, and data collected before 1990. Three reviewers independently selected studies, extracted data, and appraised quality. Quality criteria for incidence/prevalence studies were adapted from the Joanna Briggs Institute. We used random-effects models to obtain weighted pooled estimates of incidence risk for each outcome and metaregression to identify study-level characteristics affecting incidence. From 31,528 potentially relevant articles, we included 111 studies of infection in women in labour or postpartum from 46 countries. Four studies were randomised controlled trials, two were before-after intervention studies, and the remainder were observational cohort or cross-sectional studies. The pooled incidence in high-quality studies was 3.9% (95% Confidence Interval [CI] 1.8%-6.8%) for chorioamnionitis, 1.6% (95% CI 0.9%-2.5%) for endometritis, 1.2% (95% CI 1.0%-1.5%) for wound infection, 0.05% (95% CI 0.03%-0.07%) for sepsis, and 1.1% (95% CI 0.3%-2.4%) for maternal peripartum infection. 19% of studies met all quality criteria. There were few data from developing countries and marked heterogeneity in study designs and infection definitions, limiting the interpretation of these estimates as measures of global infection incidence. A limitation of this review is the inclusion of studies that were facility-based or restricted to low-risk groups of women.
CONCLUSIONS
In this study, we observed pooled infection estimates of almost 4% in labour and between 1%-2% of each infection outcome postpartum. This indicates maternal peripartum infection is an important complication of childbirth and that preventive efforts should be increased in light of antimicrobial resistance. Incidence risk appears lower than modelled global estimates, although differences in definitions limit comparability. Better-quality research, using standard definitions, is required to improve comparability between study settings and to demonstrate the influence of risk factors and protective interventions.
Topics: Anti-Bacterial Agents; Cesarean Section; Cross-Sectional Studies; Delivery, Obstetric; Female; Humans; Infections; Labor, Obstetric; Parturition; Peripartum Period; Postpartum Period; Pregnancy; Sepsis
PubMed: 31821329
DOI: 10.1371/journal.pmed.1002984 -
Einstein (Sao Paulo, Brazil) 2015Sexual activity during adolescence can lead to unwanted pregnancy, which in turn can result in serious maternal and fetal complications. The present study aimed to... (Review)
Review
Sexual activity during adolescence can lead to unwanted pregnancy, which in turn can result in serious maternal and fetal complications. The present study aimed to evaluate the complications related to adolescent pregnancy, through a systematic review using the Medical Subject Headings: "pregnancy complication" AND "adolescent" OR "pregnancy in adolescence". Only full original articles in English or Portuguese with a clearly described methodology, were included. No qualitative studies, reviews or meta-analyses, editorials, case series, or case reports were included. The sample consisted of 15 articles; in that 10 were cross-sectional and 5 were cohort studies. The overall prevalence of adolescent pregnancy was 10%, and among the Brazilian studies, the adolescent pregnancy rate was 26%. The cesarean delivery rate was lower than that reported in the general population. The main maternal and neonatal complications were hypertensive disorders of pregnancy, prematurity and low birth weight, respectively. Adolescent pregnancy is related to increased frequency of neonatal and maternal complications and lower prevalence of cesarean delivery.
Topics: Adolescent; Brazil; Cohort Studies; Cross-Sectional Studies; Female; Humans; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Pregnancy in Adolescence; Premature Birth; Prevalence; Risk Factors
PubMed: 26061075
DOI: 10.1590/S1679-45082015RW3127 -
The Cochrane Database of Systematic... Jul 2015Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve other maternal and birth outcomes.
OBJECTIVES
To assess the effects of daily oral iron supplements for pregnant women, either alone or in conjunction with folic acid, or with other vitamins and minerals as a public health intervention in antenatal care.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2015). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (26 February 2015) and contacted relevant organisations for the identification of ongoing and unpublished studies (26 February 2015) .
SELECTION CRITERIA
Randomised or quasi-randomised trials evaluating the effects of oral preventive supplementation with daily iron, iron + folic acid or iron + other vitamins and minerals during pregnancy.
DATA COLLECTION AND ANALYSIS
We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. We used the GRADE approach to assess the quality of the evidence for primary outcomes.We anticipated high heterogeneity among trials and we pooled trial results using a random-effects model and were cautious in our interpretation of the pooled results: the random-effects model gives the average treatment effect.
MAIN RESULTS
We included 61 trials. Forty-four trials, involving 43,274 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo.Preventive iron supplementation reduced maternal anaemia at term by 70% (risk ratio (RR) 0.30; 95% confidence interval (CI) 0.19 to 0.46, 14 trials, 2199 women, low quality evidence), iron-deficiency anaemia at term (RR 0.33; 95% CI 0.16 to 0.69, six trials, 1088 women), and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women, low quality evidence). There were no clear differences between groups for severe anaemia in the second or third trimester, or maternal infection during pregnancy (RR 0.22; 95% CI 0.01 to 3.20, nine trials, 2125 women, very low quality evidence; and, RR 1.21; 95% CI 0.33 to 4.46; one trial, 727 women, low quality evidence, respectively), or maternal mortality (RR 0.33; 95% CI 0.01 to 8.19, two trials, 12,560 women, very low quality evidence), or reporting of side effects (RR 1.29; 95% CI 0.83 to 2.02, 11 trials, 2423 women, very low quality evidence). Women receiving iron were on average more likely to have higher haemoglobin (Hb) concentrations at term and in the postpartum period, but were at increased risk of Hb concentrations greater than 130 g/L during pregnancy, and at term.Compared with controls, women taking iron supplements less frequently had low birthweight newborns (8.4% versus 10.3%, average RR 0.84; 95% CI 0.69 to 1.03, 11 trials, 17,613 women, low quality evidence), and preterm babies (RR 0.93; 95% CI 0.84 to 1.03, 13 trials, 19,286 women, moderate quality evidence). They appeared to also deliver slightly heavier babies (mean difference (MD) 23.75; 95% CI -3.02 to 50.51, 15 trials, 18,590 women, moderate quality evidence). None of these results were statistically significant. There were no clear differences between groups for neonatal death (RR 0.91; 95% CI 0.71 to 1.18, four trials, 16,603 infants, low quality evidence), or congenital anomalies (RR 0.88, 95% CI 0.58 to 1.33, four trials, 14,636 infants, low quality evidence).Twenty-three studies were conducted in countries that in 2011 had some malaria risk in parts of the country. In some of these countries/territories, malaria is present only in certain areas or up to a particular altitude. Only two of these studies reported malaria outcomes. There is no evidence that iron supplementation increases placental malaria. For some outcomes heterogeneity was higher than 50%.
AUTHORS' CONCLUSIONS
Supplementation reduces the risk of maternal anaemia and iron deficiency in pregnancy but the positive effect on other maternal and infant outcomes is less clear. Implementation of iron supplementation recommendations may produce heterogeneous results depending on the populations' background risk for low birthweight and anaemia, as well as the level of adherence to the intervention.
Topics: Anemia, Iron-Deficiency; Dietary Supplements; Female; Folic Acid; Humans; Infant, Low Birth Weight; Infant, Newborn; Iron; Iron, Dietary; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Outcome; Prenatal Care; Randomized Controlled Trials as Topic
PubMed: 26198451
DOI: 10.1002/14651858.CD004736.pub5 -
The American Journal of Medicine Jun 2022Severe gestational hypertriglyceridemia can lead to acute pancreatitis, with maternal mortality rate of approximately 20%. The recent National Lipid Association part 2... (Review)
Review
Severe gestational hypertriglyceridemia can lead to acute pancreatitis, with maternal mortality rate of approximately 20%. The recent National Lipid Association part 2 expert panel recommendations provide guidance on monitoring pregnant women at high risk for hyperlipidemia. We suggest that high-risk women have triglyceride levels checked once every trimester. Fasting triglycerides >250 mg/dL should prompt monthly triglyceride levels, screening for gestational diabetes, and implementing a strict low-carbohydrate, low-fat diet, exercise. Fasting triglycerides >500 mg/dL, despite a strict dietary and lifestyle modifications, should prompt treatment with omega-3-fatty acids and continue a fat-restricted diet (<20 g total fat/d or <15% total calories) under the guidance of a registered dietician. The use of fibrates should be considered as a second-line therapy due to their unclear risk versus benefit and potential teratogenic effects. Plasmapheresis should be considered early in asymptomatic pregnant women with fasting triglyceride levels >1000 mg/dL or in pregnant women with clinical signs and symptoms of pancreatitis and triglyceride levels >500 mg/dL despite maximal lifestyle changes and pharmacologic therapy.
Topics: Acute Disease; Female; Humans; Hypertriglyceridemia; Pancreatitis; Plasmapheresis; Pregnancy; Triglycerides
PubMed: 35081380
DOI: 10.1016/j.amjmed.2021.12.006 -
The Cochrane Database of Systematic... Apr 2017Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- to middle-income countries. They are exacerbated in pregnancy due to the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Multiple-micronutrient (MMN) deficiencies often coexist among women of reproductive age in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother and developing fetus. Though supplementation with MMNs has been recommended earlier because of the evidence of impact on pregnancy outcomes, a consensus is yet to be reached regarding the replacement of iron and folic acid supplementation with MMNs. Since the last update of this Cochrane review, evidence from a few large trials has recently been made available, the inclusion of which is critical to inform policy.
OBJECTIVES
To evaluate the benefits of oral multiple-micronutrient supplementation during pregnancy on maternal, fetal and infant health outcomes.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 March 2015) and reference lists of retrieved articles and key reviews. We also contacted experts in the field for additional and ongoing trials.
SELECTION CRITERIA
All prospective randomised controlled trials evaluating MMN supplementation with iron and folic acid during pregnancy and its effects on the pregnancy outcome were eligible, irrespective of language or the publication status of the trials. We included cluster-randomised trials, but quasi-randomised trials were excluded.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.
MAIN RESULTS
Nineteen trials (involving 138,538 women) were identified as eligible for inclusion in this review but only 17 trials (involving 137,791 women) contributed data to the review. Fifteen of these 17 trials were carried out in low and middle-income countries and compared MMN supplements with iron and folic acid versus iron with or without folic acid. Two trials carried out in the UK compared MMN with a placebo. MMN with iron and folic acid versus iron, with or without folic acid (15 trials): MMN resulted in a significant decrease in the number of newborn infants identified as low birthweight (LBW) (average risk ratio (RR) 0.88, 95% confidence interval (CI) 0.85 to 0.91; high-quality evidence) or small-for-gestational age (SGA) (average RR 0.92, 95% CI 0.86 to 0.98; moderate-quality evidence). No significant differences were shown for other maternal and pregnancy outcomes: preterm births (average RR 0.96, 95% CI 0.90 to 1.03; high-quality evidence), stillbirth (average RR 0.97, 95% CI 0.87, 1.09; high-quality evidence), maternal anaemia in the third trimester (average RR 1.03, 95% CI 0.85 to 1.24), miscarriage (average RR 0.91, 95% CI 0.80 to 1.03), maternal mortality (average RR 0.97, 95% CI 0.63 to 1.48), perinatal mortality (average RR 1.01, 95% CI 0.91 to 1.13; high-quality evidence), neonatal mortality (average RR 1.06, 95% CI 0.92 to 1.22; high-quality evidence), or risk of delivery via a caesarean section (average RR 1.04; 95% CI 0.74 to 1.46).A number of prespecified, clinically important outcomes could not be assessed due to insufficient or non-available data. Single trials reported results for: very preterm birth < 34 weeks, macrosomia, side-effects of supplements, nutritional status of children, and congenital anomalies including neural tube defects and neurodevelopmental outcome: Bayley Scales of Infant Development (BSID) scores. None of these trials reported pre-eclampsia, placental abruption, premature rupture of membranes, cost of supplementation, and maternal well-being or satisfaction.When assessed according to GRADE criteria, the quality of evidence for the review's primary outcomes overall was good. Pooled results for primary outcomes were based on multiple trials with large sample sizes and precise estimates. The following outcomes were graded to be as of high quality: preterm birth, LBW, perinatal mortality, stillbirth and neonatal mortality. The outcome of SGA was graded to be of moderate quality, with evidence downgraded by one for funnel plot asymmetry and potential publication bias.We carried out sensitivity analysis excluding trials with high levels of sample attrition (> 20%); results were consistent with the main analysis except for the findings for SGA (average RR 0.91, 95% CI 0.84 to 1.00). We explored heterogeneity through subgroup analyses by maternal height and body mass index (BMI), timing of supplementation and dose of iron. Subgroup differences were observed for maternal BMI for the outcome preterm birth, with significant findings among women with low BMI. Subgroup differences were also observed for maternal BMI and maternal height for the outcome SGA, indicating a significant impact among women with higher maternal BMI and height. The overall analysis of perinatal mortality, although showed a non-significant effect of MMN supplements versus iron with or without folic acid, was found to have substantial statistical heterogeneity. Subgroup differences were observed for timing of supplementation for this outcome, indicating a significantly higher impact with late initiation of supplementation. The findings between subgroups for other primary outcomes were inconclusive. MMN versus placebo (two trials): A single trial in the UK found no clear differences between groups for preterm birth, SGA, LBW or maternal anaemia in the third trimester. A second trial reported the number of women with pre-eclampsia; there was no evidence of a difference between groups. Other outcomes were not reported.
AUTHORS' CONCLUSIONS
Our findings support the effect of MMN supplements with iron and folic acid in improving some birth outcomes. Overall, pregnant women who received MMN supplementation had fewer low birthweight babies and small-for-gestational-age babies. The findings, consistently observed in several systematic evaluations of evidence, provide a basis to guide the replacement of iron and folic acid with MMN supplements containing iron and folic acid for pregnant women in low and middle-income countries where MMN deficiencies are common among women of reproductive age. Efforts could focus on the integration of this intervention in maternal nutrition and antenatal care programs in low and middle-income countries.
Topics: Dietary Supplements; Drug Interactions; Female; Folic Acid; Humans; Iron, Dietary; Micronutrients; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Premature Birth; Randomized Controlled Trials as Topic
PubMed: 28407219
DOI: 10.1002/14651858.CD004905.pub5