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Scientific Reports Aug 2021Understanding changes in oral flora during pregnancy, its association to maternal health, and its implications to birth outcomes is essential. We searched PubMed,... (Meta-Analysis)
Meta-Analysis
Understanding changes in oral flora during pregnancy, its association to maternal health, and its implications to birth outcomes is essential. We searched PubMed, Embase, Web of Science, and Cochrane Library in May 2020 (updated search in April and June 2021), and conducted a systematic review and meta-analyses to assess the followings: (1) oral microflora changes throughout pregnancy, (2) association between oral microorganisms during pregnancy and maternal oral/systemic conditions, and (3) implications of oral microorganisms during pregnancy on birth outcomes. From 3983 records, 78 studies were included for qualitative assessment, and 13 studies were included in meta-analysis. The oral microflora remains relatively stable during pregnancy; however, pregnancy was associated with distinct composition/abundance of oral microorganisms when compared to postpartum/non-pregnant status. Oral microflora during pregnancy appears to be influenced by oral and systemic conditions (e.g. gestational diabetes mellitus, pre-eclampsia, etc.). Prenatal dental care reduced the carriage of oral pathogens (e.g. Streptococcus mutans). The Porphyromonas gingivalis in subgingival plaque was more abundant in women with preterm birth. Given the results from meta-analyses were inconclusive since limited studies reported outcomes on the same measuring scale, more future studies are needed to elucidate the association between pregnancy oral microbiota and maternal oral/systemic health and birth outcomes.
Topics: Female; Humans; Microbiota; Mouth; Periodontal Diseases; Pregnancy; Pregnancy Outcome; Premature Birth; Publication Bias; Risk
PubMed: 34413437
DOI: 10.1038/s41598-021-96495-1 -
BJOG : An International Journal of... Oct 2022Calcium supplementation reduces the risk of pre-eclampsia, but questions remain about the dosage to prescribe and who would benefit most. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Calcium supplementation reduces the risk of pre-eclampsia, but questions remain about the dosage to prescribe and who would benefit most.
OBJECTIVES
To evaluate the effectiveness of high (≥1 g/day) and low (<1 g/day) calcium dosing for pre-eclampsia prevention, according to baseline dietary calcium, pre-eclampsia risk and co-interventions, and intervention timing.
SEARCH STRATEGY
CENTRAL, PubMed, Global Index Medicus and CINAHL, from inception to 2 February 2021, clinical trial registries, reference lists and expert input (CRD42018111239).
SELECTION CRITERIA
Randomised controlled trials of calcium supplementation for pre-eclampsia prevention, for women before or during pregnancy. Network meta-analysis (NMA) also included trials of different calcium doses.
DATA COLLECTION AND ANALYSIS
Two independent reviewers extracted published data. The meta-analysis employed random-effects models and the NMA, a Bayesian random-effects model, to obtain direct and indirect effect estimates.
MAIN RESULTS
The meta-analysis included 30 trials (N = 20 445 women), and the NMA to evaluate calcium dosage included 25 trials (N = 15 038). Calcium supplementation prevented pre-eclampsia similarly with a high dose (RR 0.49, 95% CI 0.36-0.66) or a low dose (RR 0.49, 95% CI 0.36-0.65). By NMA, high-dose (vs low-dose) calcium did not differ in effect (RR 0.79, 95% CI 0.43-1.40). Calcium was similarly effective regardless of baseline pre-eclampsia risk, vitamin D co-administration or timing of calcium initiation, but calcium was ineffective among women with adequate average baseline calcium intake.
CONCLUSIONS
Low- and high-dose calcium supplementation are effective for pre-eclampsia prevention in women with low calcium intake. This has implications for population-level implementation where dietary calcium is low, and targeted implementation where average intake is adequate.
TWEETABLE ABSTRACT
A network meta-analysis of 25 trials found that low-dose calcium supplementation (<1 g/day) is as effective as high-dose calcium supplementation (≥1 g/day) in halving the risk of pre-eclampsia when baseline calcium intake is low.
Topics: Bayes Theorem; Calcium; Calcium, Dietary; Dietary Supplements; Female; Humans; Network Meta-Analysis; Pre-Eclampsia; Pregnancy; Prenatal Care
PubMed: 35596262
DOI: 10.1111/1471-0528.17222 -
The Lancet. Diabetes & Endocrinology Apr 2022Adequate maternal thyroid function is important for an uncomplicated pregnancy. Although multiple observational studies have evaluated the association between thyroid... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Adequate maternal thyroid function is important for an uncomplicated pregnancy. Although multiple observational studies have evaluated the association between thyroid dysfunction and hypertensive disorders of pregnancy, the methods and definitions of abnormalities in thyroid function tests were heterogeneous, and the results were conflicting. We aimed to examine the association between abnormalities in thyroid function tests and risk of gestational hypertension and pre-eclampsia.
METHODS
In this systematic review and meta-analysis of individual-participant data, we searched MEDLINE (Ovid), Embase, Scopus, and the Cochrane Database of Systematic Reviews from date of inception to Dec 27, 2019, for prospective cohort studies with data on maternal concentrations of thyroid-stimulating hormone (TSH), free thyroxine (FT), thyroid peroxidase (TPO) antibodies, individually or in combination, as well as on gestational hypertension, pre-eclampsia, or both. We issued open invitations to study authors to participate in the Consortium on Thyroid and Pregnancy and to share the individual-participant data. We excluded participants who had pre-existing thyroid disease or multifetal pregnancy, or were taking medications that affect thyroid function. The primary outcomes were documented gestational hypertension and pre-eclampsia. Individual-participant data were analysed using logistic mixed-effects regression models adjusting for maternal age, BMI, smoking, parity, ethnicity, and gestational age at blood sampling. The study protocol was registered with PROSPERO, CRD42019128585.
FINDINGS
We identified 1539 published studies, of which 33 cohorts met the inclusion criteria and 19 cohorts were included after the authors agreed to participate. Our study population comprised 46 528 pregnant women, of whom 39 826 (85·6%) women had sufficient data (TSH and FT concentrations and TPO antibody status) to be classified according to their thyroid function status. Of these women, 1275 (3·2%) had subclinical hypothyroidism, 933 (2·3%) had isolated hypothyroxinaemia, 619 (1·6%) had subclinical hyperthyroidism, and 337 (0·8%) had overt hyperthyroidism. Compared with euthyroidism, subclinical hypothyroidism was associated with a higher risk of pre-eclampsia (2·1% vs 3·6%; OR 1·53 [95% CI 1·09-2·15]). Subclinical hyperthyroidism, isolated hypothyroxinaemia, or TPO antibody positivity were not associated with gestational hypertension or pre-eclampsia. In continuous analyses, both a higher and a lower TSH concentration were associated with a higher risk of pre-eclampsia (p=0·0001). FT concentrations were not associated with the outcomes measured.
INTERPRETATION
Compared with euthyroidism, subclinical hypothyroidism during pregnancy was associated with a higher risk of pre-eclampsia. There was a U-shaped association of TSH with pre-eclampsia. These results quantify the risks of gestational hypertension or pre-eclampsia in women with thyroid function test abnormalities, adding to the total body of evidence on the risk of adverse maternal and fetal outcomes of thyroid dysfunction during pregnancy. These findings have potential implications for defining the optimal treatment target in women treated with levothyroxine during pregnancy, which needs to be assessed in future interventional studies.
FUNDING
Arkansas Biosciences Institute and Netherlands Organization for Scientific Research.
Topics: Female; Humans; Hypertension, Pregnancy-Induced; Hyperthyroidism; Hypothyroidism; Male; Pre-Eclampsia; Pregnancy; Pregnancy Complications; Prospective Studies; Thyroid Diseases; Thyrotropin; Thyroxine
PubMed: 35255260
DOI: 10.1016/S2213-8587(22)00007-9 -
The Cochrane Database of Systematic... Oct 2019Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, low-dose aspirin in particular, might prevent or delay development of pre-eclampsia.
OBJECTIVES
To assess the effectiveness and safety of antiplatelet agents, such as aspirin and dipyridamole, when given to women at risk of developing pre-eclampsia.
SEARCH METHODS
For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (30 March 2018), and reference lists of retrieved studies. We updated the search in September 2019 and added the results to the awaiting classification section of the review.
SELECTION CRITERIA
All randomised trials comparing antiplatelet agents with either placebo or no antiplatelet agent were included. Studies only published in abstract format were eligible for inclusion if sufficient information was available. We would have included cluster-randomised trials in the analyses along with individually-randomised trials, if any had been identified in our search strategy. Quasi-random studies were excluded. Participants were pregnant women at risk of developing pre-eclampsia. Interventions were administration of an antiplatelet agent (such as low-dose aspirin or dipyridamole), comparisons were either placebo or no antiplatelet.
DATA COLLECTION AND ANALYSIS
Two review authors assessed trials for inclusion and extracted data independently. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For this update we incorporated individual participant data (IPD) from trials with this available, alongside aggregate data (AD) from trials where it was not, in order to enable reliable subgroup analyses and inclusion of two key new outcomes. We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE.
MAIN RESULTS
Seventy-seven trials (40,249 women, and their babies) were included, although three trials (relating to 233 women) did not contribute data to the meta-analysis. Nine of the trials contributing data were large (> 1000 women recruited), accounting for 80% of women recruited. Although the trials took place in a wide range of countries, all of the nine large trials involved only women in high-income and/or upper middle-income countries. IPD were available for 36 trials (34,514 women), including all but one of the large trials. Low-dose aspirin alone was the intervention in all the large trials, and most trials overall. Dose in the large trials was 50 mg (1 trial, 1106 women), 60 mg (5 trials, 22,322 women), 75mg (1 trial, 3697 women) 100 mg (1 trial, 3294 women) and 150 mg (1 trial, 1776 women). Most studies were either low risk of bias or unclear risk of bias; and the large trials were all low risk of bas. Antiplatelet agents versus placebo/no treatment The use of antiplatelet agents reduced the risk of proteinuric pre-eclampsia by 18% (36,716 women, 60 trials, RR 0.82, 95% CI 0.77 to 0.88; high-quality evidence), number needed to treat for one women to benefit (NNTB) 61 (95% CI 45 to 92). There was a small (9%) reduction in the RR for preterm birth <37 weeks (35,212 women, 47 trials; RR 0.91, 95% CI 0.87 to 0.95, high-quality evidence), NNTB 61 (95% CI 42 to 114), and a 14% reduction infetal deaths, neonatal deaths or death before hospital discharge (35,391 babies, 52 trials; RR 0.85, 95% CI 0.76 to 0.95; high-quality evidence), NNTB 197 (95% CI 115 to 681). Antiplatelet agents slightly reduced the risk of small-for-gestational age babies (35,761 babies, 50 trials; RR 0.84, 95% CI 0.76 to 0.92; high-quality evidence), NNTB 146 (95% CI 90 to 386), and pregnancies with serious adverse outcome (a composite outcome including maternal death, baby death, pre-eclampsia, small-for-gestational age, and preterm birth) (RR 0.90, 95% CI 0.85 to 0.96; 17,382 women; 13 trials, high-quality evidence), NNTB 54 (95% CI 34 to 132). Antiplatelet agents probably slightly increase postpartum haemorrhage > 500 mL (23,769 women, 19 trials; RR 1.06, 95% CI 1.00 to 1.12; moderate-quality evidence due to clinical heterogeneity), and they probably marginally increase the risk of placental abruption, although for this outcome the evidence was downgraded due to a wide confidence interval including the possibility of no effect (30,775 women; 29 trials; RR 1.21, 95% CI 0.95 to 1.54; moderate-quality evidence). Data from two large trials which assessed children at aged 18 months (including results from over 5000 children), did not identify clear differences in development between the two groups.
AUTHORS' CONCLUSIONS
Administering low-dose aspirin to pregnant women led to small-to-moderate benefits, including reductions in pre-eclampsia (16 fewer per 1000 women treated), preterm birth (16 fewer per 1000 treated), the baby being born small-for-gestational age (seven fewer per 1000 treated) and fetal or neonatal death (five fewer per 1000 treated). Overall, administering antiplatelet agents to 1000 women led to 20 fewer pregnancies with serious adverse outcomes. The quality of evidence for all these outcomes was high. Aspirin probably slightly increased the risk of postpartum haemorrhage of more than 500 mL, however, the quality of evidence for this outcome was downgraded to moderate, due to concerns of clinical heterogeneity in measurements of blood loss. Antiplatelet agents probably marginally increase placental abruption, but the quality of the evidence was downgraded to moderate due to low event numbers and thus wide 95% CI. Overall, antiplatelet agents improved outcomes, and at these doses appear to be safe. Identifying women who are most likely to respond to low-dose aspirin would improve targeting of treatment. As almost all the women in this review were recruited to the trials after 12 weeks' gestation, it is unclear whether starting treatment before 12 weeks' would have additional benefits without any increase in adverse effects. While there was some indication that higher doses of aspirin would be more effective, further studies would be warranted to examine this.
Topics: Aspirin; Female; Gestational Age; Humans; Infant, Newborn; Infant, Small for Gestational Age; Maternal Mortality; Platelet Aggregation Inhibitors; Pre-Eclampsia; Pregnancy; Premature Birth; Prenatal Care; Randomized Controlled Trials as Topic
PubMed: 31684684
DOI: 10.1002/14651858.CD004659.pub3 -
American Journal of Preventive Medicine Jul 2021Low-dose aspirin is used for pre-eclampsia prophylaxis during pregnancy, but a study that comprehensively investigates both maternal and perinatal outcomes from aspirin... (Meta-Analysis)
Meta-Analysis Review
CONTEXT
Low-dose aspirin is used for pre-eclampsia prophylaxis during pregnancy, but a study that comprehensively investigates both maternal and perinatal outcomes from aspirin administration utilizing stratification methods is lacking. The aim of this study is to comprehensively investigate the maternal and neonatal outcomes related to aspirin prophylaxis during pregnancy in relation to dose and therapy initiation by utilizing a stratification method.
EVIDENCE ACQUISITION
Placebo-controlled randomized trials investigating the effect of low-dose aspirin on maternal or perinatal outcomes with sufficient raw data and published in English from inception to August 2020 were searched for from PubMed, Embase, Cochrane Library, and Google Scholar in accordance with PRISMA guidelines. Review articles, editorials, case reports, conference abstracts, and nonplacebo-controlled studies were excluded.
EVIDENCE SYNTHESIS
A total of 35 placebo-controlled randomized trials with 46,568 pregnant women were included in this meta-analysis. Aspirin prophylaxis substantially lowered the risk of pre-eclampsia, preterm birth, perinatal mortality, and intrauterine growth retardation without elevated bleeding risks. Low-dose aspirin considerably enhanced neonatal birth weight but did not decrease the risk of gestational hypertension. The subgroup analysis revealed substantially reduced pre-eclampsia risk and enhanced birth weight and gestational age at delivery in women who initiated aspirin before 20 weeks of gestation (RR=0.76, 95% CI=0.64, 0.90, p=0.001). However, the effect of aspirin dose on pregnancy outcomes was insignificant and requires further evaluation.
CONCLUSIONS
Initiation of low-dose aspirin administration before 20 weeks of gestation considerably decreases the incidence of pre-eclampsia and related neonatal outcomes without increasing bleeding risk.
Topics: Aspirin; Female; Gestational Age; Humans; Infant, Newborn; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; Premature Birth
PubMed: 33795180
DOI: 10.1016/j.amepre.2021.01.032 -
American Journal of Obstetrics and... May 2022Limited evidence exists on the role that the cause of chronic kidney disease plays in determining pregnancy outcomes. The aim of this systematic review and meta-analysis... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Limited evidence exists on the role that the cause of chronic kidney disease plays in determining pregnancy outcomes. The aim of this systematic review and meta-analysis was to examine the association between chronic kidney disease and adverse pregnancy outcomes by the cause and severity of chronic kidney disease where reported. The protocol was registered under the International Prospective Register of Systematic Reviews (CRD42020211925).
DATA SOURCES
PubMed, Embase, and Web of Science were searched until May 24, 2021, supplemented with reference list checking.
STUDY ELIGIBILITY CRITERIA
Studies that compared the pregnancy outcomes in women with or without chronic kidney disease were included. Two reviewers independently screened titles, abstracts, and full-text articles according to a priori defined inclusion criteria.
METHODS
Data extraction and quality appraisal were performed independently by 3 reviewers. The grading of recommendations, assessment, development, and evaluation approach was used to assess the overall certainty of the evidence. Random-effects meta-analyses were used to calculate the pooled estimates using the generic inverse variance method. The primary outcomes included preeclampsia, cesarean delivery, preterm birth (<37 weeks' gestation), and small for gestational age babies.
RESULTS
Of 4076 citations, 31 studies were included. Prepregnancy chronic kidney disease was significantly associated with a higher odds of preeclampsia (pooled crude odds ratio, 8.13; [95% confidence interval, 4.41-15], and adjusted odds ratio, 2.58; [1.33-5.01]), cesarean delivery (adjusted odds ratio, 1.65; [1.21-2.25]), preterm birth (adjusted odds ratio, 1.73; [1.31-2.27]), and small for gestational age babies (adjusted odds ratio, 1.93; [1.06-3.52]). The association with stillbirth was not statistically significant (adjusted odds ratio, 1.67; [0.96-2.92]). Subgroup analyses indicated that different causes of chronic kidney disease might confer different risks and that the severity of chronic kidney disease is associated with a risk of adverse pregnancy outcomes, as pregnancies with later stages of chronic kidney disease had higher odds of preeclampsia, preterm birth, and small for gestational age babies than those at earlier stages. The grading of recommendations, assessment, development, and evaluation certainty of the evidence overall was "very low".
CONCLUSION
This meta-analysis quantified the associations between prepregnancy chronic kidney disease and adverse pregnancy outcomes, both overall and according to the cause and severity of the disease. These findings might support the clinicians aiming to counsel women having chronic kidney disease by allowing them to tailor their advice according to cause and severity of the chronic kidney disease. We identified the gaps in the literature, and further studies examining the effect of specific kidney diseases and other clinical characteristics (eg, proteinuria, hypertension) on adverse pregnancy outcomes are warranted.
Topics: Female; Humans; Infant, Newborn; Infant, Small for Gestational Age; Male; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; Premature Birth; Renal Insufficiency, Chronic
PubMed: 34736915
DOI: 10.1016/j.ajog.2021.10.037 -
Nutrients Feb 2020Almost two billion people are deficient in key vitamins and minerals, mostly women and children in low- and middle-income countries (LMICs). Deficiencies worsen during... (Meta-Analysis)
Meta-Analysis
Vitamin and Mineral Supplementation During Pregnancy on Maternal, Birth, Child Health and Development Outcomes in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.
Almost two billion people are deficient in key vitamins and minerals, mostly women and children in low- and middle-income countries (LMICs). Deficiencies worsen during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child, but could be mitigated by interventions like micronutrient supplementation. To our knowledge, this is the first systematic review that aimed to compile evidence from both efficacy and effectiveness trials, evaluating different supplementation interventions on maternal, birth, child health, and developmental outcomes. We evaluated randomized controlled trials and quasi-experimental studies published since 1995 in peer-reviewed and grey literature that assessed the effects of calcium, vitamin A, iron, vitamin D, and zinc supplementation compared to placebo/no treatment; iron-folic (IFA) supplementation compared to folic acid only; multiple micronutrient (MMN) supplementation compared to IFA; and lipid-based nutrient supplementation (LNS) compared to MMN supplementation. Seventy-two studies, which collectively involved 314 papers (451,723 women), were included. Meta-analyses showed improvement in several key birth outcomes, such as preterm birth, small-for-gestational age (SGA) and low birthweight with MMN supplementation, compared to IFA. MMN also improved child outcomes, including diarrhea incidence and retinol concentration, which are findings not previously reported. Across all comparisons, micronutrient supplementation had little to no effect on mortality (maternal, neonatal, perinatal, and infant) outcomes, which is consistent with other systematic reviews. IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities. For single micronutrient supplementation, improvements were noted in only a few outcomes, mainly pre-eclampsia/eclampsia (calcium), maternal anemia (iron), preterm births (vitamin D), and maternal serum zinc concentration (zinc). These findings highlight that micronutrient-specific supplementation should be tailored to specific groups or needs for maximum benefit. In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.
Topics: Anemia; Child; Child Development; Child, Preschool; Developing Countries; Dietary Supplements; Female; Humans; Income; Infant; Maternal Nutritional Physiological Phenomena; Micronutrients; Minerals; Poverty Areas; Pre-Eclampsia; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Premature Birth; Randomized Controlled Trials as Topic; Vitamins
PubMed: 32075071
DOI: 10.3390/nu12020491 -
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 -
Ultrasound in Obstetrics & Gynecology :... Jul 2019Primary studies and systematic reviews provide estimates of varying accuracy for different factors in the prediction of pre-eclampsia. The aim of this study was to...
OBJECTIVE
Primary studies and systematic reviews provide estimates of varying accuracy for different factors in the prediction of pre-eclampsia. The aim of this study was to review published systematic reviews to collate evidence on the ability of available tests to predict pre-eclampsia, to identify high-value avenues for future research and to minimize future research waste in this field.
METHODS
MEDLINE, EMBASE and The Cochrane Library including DARE (Database of Abstracts of Reviews of Effects) databases, from database inception to March 2017, and bibliographies of relevant articles were searched, without language restrictions, for systematic reviews and meta-analyses on the prediction of pre-eclampsia. The quality of the included reviews was assessed using the AMSTAR tool and a modified version of the QUIPS tool. We evaluated the comprehensiveness of search, sample size, tests and outcomes evaluated, data synthesis methods, predictive ability estimates, risk of bias related to the population studied, measurement of predictors and outcomes, study attrition and adjustment for confounding.
RESULTS
From 2444 citations identified, 126 reviews were included, reporting on over 90 predictors and 52 prediction models for pre-eclampsia. Around a third (n = 37 (29.4%)) of all reviews investigated solely biochemical markers for predicting pre-eclampsia, 31 (24.6%) investigated genetic associations with pre-eclampsia, 46 (36.5%) reported on clinical characteristics, four (3.2%) evaluated only ultrasound markers and six (4.8%) studied a combination of tests; two (1.6%) additional reviews evaluated primary studies investigating any screening test for pre-eclampsia. Reviews included between two and 265 primary studies, including up to 25 356 688 women in the largest review. Only approximately half (n = 67 (53.2%)) of the reviews assessed the quality of the included studies. There was a high risk of bias in many of the included reviews, particularly in relation to population representativeness and study attrition. Over 80% (n = 106 (84.1%)) summarized the findings using meta-analysis. Thirty-two (25.4%) studies lacked a formal statement on funding. The predictors with the best test performance were body mass index (BMI) > 35 kg/m , with a specificity of 92% (95% CI, 89-95%) and a sensitivity of 21% (95% CI, 12-31%); BMI > 25 kg/m , with a specificity of 73% (95% CI, 64-83%) and a sensitivity of 47% (95% CI, 33-61%); first-trimester uterine artery pulsatility index or resistance index > 90 centile (specificity 93% (95% CI, 90-96%) and sensitivity 26% (95% CI, 23-31%)); placental growth factor (specificity 89% (95% CI, 89-89%) and sensitivity 65% (95% CI, 63-67%)); and placental protein 13 (specificity 88% (95% CI, 87-89%) and sensitivity 37% (95% CI, 33-41%)). No single marker had a test performance suitable for routine clinical use. Models combining markers showed promise, but none had undergone external validation.
CONCLUSIONS
This review of reviews calls into question the need for further aggregate meta-analysis in this area given the large number of published reviews subject to the common limitations of primary predictive studies. Prospective, well-designed studies of predictive markers, preferably randomized intervention studies, and combined through individual-patient data meta-analysis are needed to develop and validate new prediction models to facilitate the prediction of pre-eclampsia and minimize further research waste in this field. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Topics: Adult; Biomarkers; Body Mass Index; Female; Humans; Mass Screening; Meta-Analysis as Topic; Placenta Growth Factor; Pre-Eclampsia; Predictive Value of Tests; Pregnancy; Pregnancy Complications; Prospective Studies; Pulsatile Flow; Risk Factors; Sensitivity and Specificity; Ultrasonography; Uterine Artery
PubMed: 30267475
DOI: 10.1002/uog.20117 -
Autoimmunity Reviews Oct 2021To identify and assess the magnitude of effect of pregnancy outcome predictors in women with antiphospholipid syndrome (APS) by means of systematic review and... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To identify and assess the magnitude of effect of pregnancy outcome predictors in women with antiphospholipid syndrome (APS) by means of systematic review and meta-analysis.
METHODS
PubMed and Embase were searched (13th June 2020) for studies reporting on pre-pregnancy risk factors of pregnancy outcomes in APS patients. Literature screening and data extraction were conducted by two reviewers independently, in a blinded standardized manner. Pooled univariate odds ratios (OR) were computed using a random effects model. Heterogeneity was assessed by I%.
RESULTS
The search yielded 3013 unique results; 27 records were included in this meta-analysis. Previous thrombosis was associated with a decreased live birth risk (OR 0.60, p < 0.01, I = 40%), increased neonatal mortality (OR 15.19, p < 0.01, I = 0%), an increased risk of antenatal or postpartum thrombosis (OR 6.26, p < 0.01, I = 0%) and an increased risk of delivering a small for gestational age neonate (SGA) (OR 2.60, p = 0.01, I = 0%). Patients with an APS laboratory category I (double or triple positivity) profile had a decreased live birth risk (OR 0.66, p < 0.01, I = 0%), an increased risk of SGA (OR 1.86, p = 0.01, I = 43%) and preterm birth (OR 1.35, p < 0.01, I = 49%). Triple positivity was associated with a decreased live birth risk (OR 0.33, p < 0.01, I = 68%), an increased risk of preeclampsia (OR 2.43, p = 0.02, I = 35%) and SGA (OR 2.47, p = 0.04, I = 61%). Patients with lupus anticoagulant positivity had an increased risk of preeclampsia (OR 2.10, p = 0.02, I = 48%), SGA (OR 1.78, p < 0.01, I = 0%) and preterm birth (OR 3.56, p = 0.01, I = 48%). Risk of bias assessment suggested considerable bias on study participation and statistical methods.
CONCLUSIONS
The results of this meta-analysis identified previous thrombosis, laboratory category I, triple positivity and lupus anticoagulant positivity as the most important predictors of adverse pregnancy outcomes. This up-to-date knowledge, can be used in preconception counseling and tailoring of obstetric care.
Topics: Antiphospholipid Syndrome; Female; Humans; Infant, Newborn; Lupus Coagulation Inhibitor; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; Premature Birth
PubMed: 34280554
DOI: 10.1016/j.autrev.2021.102901