-
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 -
American Journal of Obstetrics and... Sep 2022To assess the efficacy and safety of vaginal progesterone to prevent recurrent preterm birth and adverse perinatal outcomes in singleton gestations with a history of... (Meta-Analysis)
Meta-Analysis Review
Does vaginal progesterone prevent recurrent preterm birth in women with a singleton gestation and a history of spontaneous preterm birth? Evidence from a systematic review and meta-analysis.
OBJECTIVE
To assess the efficacy and safety of vaginal progesterone to prevent recurrent preterm birth and adverse perinatal outcomes in singleton gestations with a history of spontaneous preterm birth.
DATA SOURCES
MEDLINE, Embase, LILACS, and CINAHL (from their inception to February 28, 2022), Cochrane databases, Google Scholar, bibliographies, and conference proceedings.
STUDY ELIGIBILITY CRITERIA
Randomized controlled trials that compared vaginal progesterone to placebo or no treatment in asymptomatic women with a singleton gestation and a history of spontaneous preterm birth.
METHODS
The primary outcomes were preterm birth <37 and <34 weeks of gestation. The secondary outcomes included adverse maternal and perinatal outcomes. Pooled relative risks with 95% confidence intervals were calculated. We assessed the risk of bias in the included studies, heterogeneity (I test), small-study effects, publication bias, and quality of evidence; performed subgroup and sensitivity analyses; and calculated 95% prediction intervals and adjusted relative risks.
RESULTS
Ten studies (2958 women) met the inclusion criteria: 7 with a sample size <150 (small studies) and 3 with a sample size >600 (large studies). Among the 7 small studies, 4 were at high risk of bias, 2 were at some concerns of bias, and only 1 was at low risk of bias. All the large studies were at low risk of bias. Vaginal progesterone significantly decreased the risk of preterm birth <37 weeks (relative risk, 0.64; 95% confidence interval, 0.50-0.81; I=75%; 95% prediction interval, 0.31-1.32; very low-quality evidence) and <34 weeks (relative risk, 0.62; 95% confidence interval, 0.42-0.92; I=66%; 95% prediction interval, 0.23-1.68; very low-quality evidence), and the risk of admission to the neonatal intensive care unit (relative risk, 0.53; 95% confidence interval, 0.33-0.85; I=67%; 95% prediction interval, 0.16-1.79; low-quality evidence). There were no significant differences between the vaginal progesterone and the placebo or no treatment groups in other adverse perinatal and maternal outcomes. Subgroup analyses revealed that vaginal progesterone decreased the risk of preterm birth <37 weeks (relative risk, 0.43; 95% confidence interval, 0.33-0.55; I=0%) and <34 weeks (relative risk, 0.27; 95% confidence interval, 0.15-0.49; I=0%) in the small but not in the large studies (relative risk, 0.98; 95% confidence interval, 0.88-1.09; I=0% for preterm birth <37 weeks; and relative risk, 0.94; 95% confidence interval, 0.78-1.13; I=0% for preterm birth <34 weeks). Sensitivity analyses restricted to studies at low risk of bias indicated that vaginal progesterone did not reduce the risk of preterm birth <37 weeks (relative risk, 0.96; 95% confidence interval, 0.84-1.09) and <34 weeks (relative risk, 0.90; 95% confidence interval, 0.71-1.15). There was clear evidence of substantial small-study effects in the meta-analyses of preterm birth <37 and <34 weeks of gestation because of funnel plot asymmetry and the marked differences in the pooled relative risks obtained from fixed-effect and random-effects models. The adjustment for small-study effects resulted in a markedly reduced and nonsignificant effect of vaginal progesterone on preterm birth <37 weeks (relative risk, 0.86; 95% confidence interval, 0.68-1.10) and <34 weeks (relative risk, 0.92; 95% confidence interval, 0.60-1.42).
CONCLUSION
There is no convincing evidence supporting the use of vaginal progesterone to prevent recurrent preterm birth or to improve perinatal outcomes in singleton gestations with a history of spontaneous preterm birth.
Topics: Female; Humans; Infant, Newborn; Intensive Care Units, Neonatal; Pregnancy; Premature Birth; Progesterone; Vagina
PubMed: 35460628
DOI: 10.1016/j.ajog.2022.04.023 -
The Lancet. Global Health Jan 2019Preterm birth is the leading cause of death in children younger than 5 years worldwide. Although preterm survival rates have increased in high-income countries, preterm...
BACKGROUND
Preterm birth is the leading cause of death in children younger than 5 years worldwide. Although preterm survival rates have increased in high-income countries, preterm newborns still die because of a lack of adequate newborn care in many low-income and middle-income countries. We estimated global, regional, and national rates of preterm birth in 2014, with trends over time for some selected countries.
METHODS
We systematically searched for data on preterm birth for 194 WHO Member States from 1990 to 2014 in databases of national civil registration and vital statistics (CRVS). We also searched for population-representative surveys and research studies for countries with no or limited CRVS data. For 38 countries with high-quality data for preterm births in 2014, data are reported directly. For countries with at least three data points between 1990 and 2014, we used a linear mixed regression model to estimate preterm birth rates. We also calculated regional and global estimates of preterm birth for 2014.
FINDINGS
We identified 1241 data points across 107 countries. The estimated global preterm birth rate for 2014 was 10·6% (uncertainty interval 9·0-12·0), equating to an estimated 14·84 million (12·65 million-16·73 million) live preterm births in 2014. 12· 0 million (81·1%) of these preterm births occurred in Asia and sub-Saharan Africa. Regional preterm birth rates for 2014 ranged from 13·4% (6·3-30·9) in North Africa to 8·7% (6·3-13·3) in Europe. India, China, Nigeria, Bangladesh, and Indonesia accounted for 57·9 million (41×4%) of 139·9 million livebirths and 6·6 million (44×6%) of preterm births globally in 2014. Of the 38 countries with high-quality data, preterm birth rates have increased since 2000 in 26 countries and decreased in 12 countries. Globally, we estimated that the preterm birth rate was 9×8% (8×3-10×9) in 2000, and 10×6% (9×0-12×0) in 2014.
INTERPRETATION
Preterm birth remains a crucial issue in child mortality and improving quality of maternal and newborn care. To better understand the epidemiology of preterm birth, the quality and volume of data needs to be improved, including standardisation of definitions, measurement, and reporting.
FUNDING
WHO and the March of Dimes.
Topics: Female; Global Health; Humans; Linear Models; Pregnancy; Premature Birth
PubMed: 30389451
DOI: 10.1016/S2214-109X(18)30451-0 -
Clinical Gastroenterology and... Jan 2022Biologics are used routinely in pregnant women with inflammatory bowel disease (IBD), but large-scale data reporting adverse pregnancy outcomes among biologic users are... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND & AIMS
Biologics are used routinely in pregnant women with inflammatory bowel disease (IBD), but large-scale data reporting adverse pregnancy outcomes among biologic users are lacking. We sought to estimate the prevalence of adverse pregnancy outcomes in women with IBD on biologic therapies.
METHODS
We searched major databases from inception to June 2020 for studies estimating the prevalence of adverse pregnancy outcomes in IBD when using biologics (anti-tumor necrosis factor [TNF], anti-integrins, and anticytokines). Prevalence and relative risk (RR) were pooled using a random-effects model.
RESULTS
Forty-eight studies were included in the meta-analysis comprising 6963 patients. Biologic therapy in IBD pregnancies was associated with a pooled prevalence of 8% (95% CI, 6%-10%; I = 87.4%) for early pregnancy loss, 9% (95% CI, 7%-11%; I = 89.9%) for preterm birth, 0% (95% CI, 0%-0%; I = 0%) for stillbirth, 8% (95% CI, 5%-10%; I = 87.0%) for low birth weight, and 1% (95% CI, 1%-2%; I = 78.3%) for congenital malformations. These rates are comparable with those published in the general population. In subgroup analyses of a small number of studies, the prevalence of early pregnancy loss and preterm birth were higher in vedolizumab vs anti-TNF users. Meta-regression did not show an association of disease activity or concomitant thiopurine on adverse outcomes. Continued TNF inhibitor use during the third trimester was not associated with risk of preterm birth (RR, 1.41; 95% CI, 0.77-2.60; I = 0%), low birth weight (RR, 1.32; 95% CI, 0.80-2.18; I = 0%), or congenital malformations (RR, 1.28; 95% CI, 0.47-3.49; I = 0%).
CONCLUSIONS
Adverse pregnancy outcomes among pregnant IBD women using biologics are comparable with that of the general population. PROSPERO protocol #CRD42019135721.
Topics: Biological Products; Female; Humans; Infant, Newborn; Inflammatory Bowel Diseases; Pregnancy; Pregnancy Outcome; Premature Birth; Tumor Necrosis Factor Inhibitors
PubMed: 32931960
DOI: 10.1016/j.cgh.2020.09.021 -
International Journal of Gynaecology... Dec 2022To explore perinatal outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-vaccinated pregnant women compared with unvaccinated counterparts. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To explore perinatal outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-vaccinated pregnant women compared with unvaccinated counterparts.
METHODS
Search was conducted using Web of Science, Scopus, ClinicalTrial.gov, MEDLINE, Embase, OVID, and Cochrane Library as electronic databases. We included observational studies evaluating pregnant women undergoing SARS-CoV-2 vaccination and compared pregnancy and perinatal outcomes with those in unvaccinated women. Categorical variables were assessed using odds ratio (OR) with 95% confidence interval (CI), whereas for continuous variables, the results were expressed as mean difference with their 95% CI. All analyses were performed by adopting the random effect model of DerSimonian and Laird.
RESULTS
There was no difference in the probability of having a small-for-gestational-age fetus (OR 0.97, 95% CI 0.85-1.09; P = 0.570), but we observed a reduced probability of a non-reassuring fetal monitoring, a reduced gestational age at delivery, and a reduced probability of premature delivery in vaccinated pregnant women versus unvaccinated ones.
CONCLUSION
The probability of small for gestational age is similar between vaccinated and unvaccinated pregnant women, and the former also had a slightly reduced rate of premature delivery.
Topics: Female; Pregnancy; Humans; COVID-19 Vaccines; SARS-CoV-2; COVID-19; Premature Birth; Pregnancy Complications, Infectious; Fetal Growth Retardation; Pregnancy Outcome
PubMed: 35810414
DOI: 10.1002/ijgo.14336 -
Obstetrics and Gynecology Jun 2021To estimate the risk of maternal and neonatal sepsis associated with chorioamnionitis. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To estimate the risk of maternal and neonatal sepsis associated with chorioamnionitis.
DATA SOURCES
PubMed, BIOSIS, and ClinicalTrials.gov databases were systematically searched for full-text articles in English from inception until May 11, 2020.
METHODS OF STUDY SELECTION
We screened 1,251 studies. Randomized controlled trials, case-control, or cohort studies quantifying a relationship between chorioamnionitis and sepsis in mothers (postpartum) or neonates born at greater than 22 weeks of gestation were eligible. Studies were grouped for meta-analyses according to exposures of histologic or clinical chorioamnionitis and outcomes of maternal or neonatal sepsis.
TABULATION, INTEGRATION, AND RESULTS
One hundred three studies were included, and 55 met criteria for meta-analysis (39 studies of preterm neonates, 10 studies of general populations of preterm and term neonates, and six studies of late preterm and term neonates). Study details and quantitative data were abstracted. Random-effects models were used to generate pooled odds ratios (ORs); most studies only reported unadjusted results. Histologic chorioamnionitis was associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 4.42 [95% CI 2.68-7.29] and 5.88 [95% CI 3.68-9.41], respectively). Clinical chorioamnionitis was also associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 6.82 [95% CI 4.93-9.45] and 3.90 [95% CI 2.74-5.55], respectively). Additionally, histologic and clinical chorioamnionitis were each associated with higher odds of late-onset sepsis in preterm neonates. Confirmed sepsis incidence was 7% (early-onset) and 22% (late-onset) for histologic and 6% (early-onset) and 26% (late-onset) for clinical chorioamnionitis-exposed neonates. Three studies evaluated chorioamnionitis and maternal sepsis and were inconclusive.
CONCLUSION
Both histologic and clinical chorioamnionitis were associated with early- and late-onset sepsis in neonates. Overall, our findings support current guidelines for preventative neonatal care. There was insufficient evidence to determine the association between chorioamnionitis and maternal sepsis.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO, CRD42020156812.
Topics: Chorioamnionitis; Female; Gestational Age; Humans; Incidence; Infant, Newborn; Neonatal Sepsis; Postpartum Period; Pregnancy; Premature Birth; Sepsis; Term Birth; Time Factors
PubMed: 33957655
DOI: 10.1097/AOG.0000000000004377 -
JAMA Network Open Jun 2020Knowledge of whether serious adverse pregnancy outcomes are associated with increasingly widespread effects of climate change in the US would be crucial for the...
IMPORTANCE
Knowledge of whether serious adverse pregnancy outcomes are associated with increasingly widespread effects of climate change in the US would be crucial for the obstetrical medical community and for women and families across the country.
OBJECTIVE
To investigate prenatal exposure to fine particulate matter (PM2.5), ozone, and heat, and the association of these factors with preterm birth, low birth weight, and stillbirth.
EVIDENCE REVIEW
This systematic review involved a comprehensive search for primary literature in Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, PubMed, ClinicalTrials.gov website, and MEDLINE. Qualifying primary research studies included human participants in US populations that were published in English between January 1, 2007, and April 30, 2019. Included articles analyzed the associations between air pollutants or heat and obstetrical outcomes. Comparative observational cohort studies and cross-sectional studies with comparators were included, without minimum sample size. Additional articles found through reference review were also considered. Articles analyzing other obstetrical outcomes, non-US populations, and reviews were excluded. Two reviewers independently determined study eligibility. The Arskey and O'Malley scoping review framework was used. Data extraction was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.
FINDINGS
Of the 1851 articles identified, 68 met the inclusion criteria. Overall, 32 798 152 births were analyzed, with a mean (SD) of 565 485 (783 278) births per study. A total of 57 studies (48 of 58 [84%] on air pollutants; 9 of 10 [90%] on heat) showed a significant association of air pollutant and heat exposure with birth outcomes. Positive associations were found across all US geographic regions. Exposure to PM2.5 or ozone was associated with increased risk of preterm birth in 19 of 24 studies (79%) and low birth weight in 25 of 29 studies (86%). The subpopulations at highest risk were persons with asthma and minority groups, especially black mothers. Accurate comparisons of risk were limited by differences in study design, exposure measurement, population demographics, and seasonality.
CONCLUSIONS AND RELEVANCE
This review suggests that increasingly common environmental exposures exacerbated by climate change are significantly associated with serious adverse pregnancy outcomes across the US.
Topics: Air Pollution; Female; Hot Temperature; Humans; Infant, Low Birth Weight; Maternal Exposure; Observational Studies as Topic; Pregnancy; Premature Birth; Stillbirth; United States
PubMed: 32556259
DOI: 10.1001/jamanetworkopen.2020.8243 -
Nutrients May 2018This systematic review and meta-analysis synthesised the post-1990 literature examining the effect of human milk on morbidity, specifically necrotising enterocolitis... (Comparative Study)
Comparative Study Meta-Analysis Review
This systematic review and meta-analysis synthesised the post-1990 literature examining the effect of human milk on morbidity, specifically necrotising enterocolitis (NEC), late onset sepsis (LOS), retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD) and neurodevelopment in infants born ≤28 weeks' gestation and/or publications with reported infant mean birth weight of ≤1500 g. Online databases including Medline, PubMed, CINAHL, Scopus, and the Cochrane Central Register of Controlled Trials were searched, and comparisons were grouped as follows: exclusive human milk (EHM) versus exclusive preterm formula (EPTF), any human milk (HM) versus EPTF, higher versus lower dose HM, and unpasteurised versus pasteurised HM. Experimental and observational studies were pooled separately in meta-analyses. Risk of bias was assessed for each individual study and the GRADE system used to judge the certainty of the findings. Forty-nine studies (with 56 reports) were included, of which 44 could be included in meta-analyses. HM provided a clear protective effect against NEC, with an approximate 4% reduction in incidence. HM also provided a possible reduction in LOS, severe ROP and severe NEC. Particularly for NEC, any volume of HM is better than EPTF, and the higher the dose the greater the protection. Evidence regarding pasteurisation is inconclusive, but it appears to have no effect on some outcomes. Improving the intake of mother's own milk (MOM) and/or donor HM results in small improvements in morbidity in this population.
Topics: Enteral Nutrition; Enterocolitis, Necrotizing; Evidence-Based Medicine; Humans; Infant; Infant Formula; Infant Nutritional Physiological Phenomena; Infant, Extremely Premature; Infant, Newborn; Infant, Premature, Diseases; Infant, Very Low Birth Weight; Milk, Human; Neonatal Sepsis; Neurodevelopmental Disorders; Premature Birth; Severity of Illness Index
PubMed: 29857555
DOI: 10.3390/nu10060707 -
BMJ (Clinical Research Ed.) Nov 2020To assess whether exposure to high temperatures in pregnancy is associated with increased risk for preterm birth, low birth weight, and stillbirth. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To assess whether exposure to high temperatures in pregnancy is associated with increased risk for preterm birth, low birth weight, and stillbirth.
DESIGN
Systematic review and random effects meta-analysis.
DATA SOURCES
Medline and Web of Science searched up to September 2018, updated in August 2019.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Clinical studies on associations between high environmental temperatures, and preterm birth, birth weight, and stillbirths.
RESULTS
14 880 records and 175 full text articles were screened. 70 studies were included, set in 27 countries, seven of which were countries with low or middle income. In 40 of 47 studies, preterm births were more common at higher than lower temperatures. Exposures were classified as heatwaves, 1°C increments, and temperature threshold cutoff points. In random effects meta-analysis, odds of a preterm birth rose 1.05-fold (95% confidence interval 1.03 to 1.07) per 1°C increase in temperature and 1.16-fold (1.10 to 1.23) during heatwaves. Higher temperature was associated with reduced birth weight in 18 of 28 studies, with considerable statistical heterogeneity. Eight studies on stillbirths all showed associations between temperature and stillbirth, with stillbirths increasing 1.05-fold (1.01 to 1.08) per 1°C rise in temperature. Associations between temperature and outcomes were largest among women in lower socioeconomic groups and at age extremes. The multiple temperature metrics and lag analyses limited comparison between studies and settings.
CONCLUSIONS
Although summary effect sizes are relatively small, heat exposures are common and the outcomes are important determinants of population health. Linkages between socioeconomic status and study outcomes suggest that risks might be largest in low and middle income countries. Temperature rises with global warming could have major implications for child health.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD 42019140136 and CRD 42018118113.
Topics: Female; Hot Temperature; Humans; Infant, Low Birth Weight; Infant, Newborn; Pregnancy; Premature Birth; Risk Factors; Stillbirth
PubMed: 33148618
DOI: 10.1136/bmj.m3811 -
JAMA Pediatrics Jun 2022Animal studies have found that antenatal corticosteroids affect many organs across multiple stages of life. However, the long-term outcomes in human children are not... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Animal studies have found that antenatal corticosteroids affect many organs across multiple stages of life. However, the long-term outcomes in human children are not well understood.
OBJECTIVE
To conduct a systematic review and meta-analysis of long-term outcomes associated with preterm exposure to antenatal corticosteroids compared with no exposure in all children as well as children with preterm and full-term birth.
DATA SOURCES
Academic databases were searched for articles published from January 1, 2000, to October 29, 2021, including Ovid MEDLINE, Ovid Embase, PsycInfo, CINAHL (Cumulative Index of Nursing and Allied Health Literature), Web of Science, ClinicalTrials.gov, and Google Scholar. References of articles were also searched for relevant studies.
STUDY SELECTION
Randomized clinical trials (RCTs), quasi-RCTs, and cohort studies that assessed long-term neurodevelopmental, psychological, or other outcomes at 1 year or older in those who had preterm exposure to antenatal corticosteroids were included. No language restrictions were set.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently extracted data using a piloted data extraction form. Data on study population, pregnancy characteristics, exposure to antenatal corticosteroids, and outcomes were collected. Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines were followed, and random-effects models were used for the meta-analysis.
MAIN OUTCOMES AND MEASURES
The primary outcome was an author-defined composite of any adverse neurodevelopmental and/or psychological disorder. The secondary outcomes included specific measures of psychological disorders; neurodevelopmental delay; and anthropometric, metabolic, and cardiorespiratory outcomes.
RESULTS
A total of 30 studies met the inclusion criteria, and involved more than 1.25 million children who were at least 1 year of age when the outcomes were assessed. Exposure to a single course of antenatal corticosteroids for children with extremely preterm birth was associated with a significant reduction in risk of neurodevelopmental impairment (adjusted odds ratio, 0.69 [95% CI, 0.57-0.84]; I2 = 0%; low certainty). For children with late-preterm birth, exposure to antenatal corticosteroids was associated with a higher risk of investigation for neurocognitive disorders (n = 25 668 children; adjusted hazard ratio [aHR], 1.12 [95% CI, 1.05-1.20]; low certainty). For children with full-term birth, exposure to antenatal corticosteroids was associated with a higher risk of mental or behavioral disorders (n = 641 487 children; aHR, 1.47 [95% CI, 1.36-1.60]; low certainty) as well as proven or suspected neurocognitive disorders (n = 529 205 children; aHR, 1.16 [95% CI, 1.10-1.21]; low certainty).
CONCLUSIONS AND RELEVANCE
Results of this study showed that exposure to a single course of antenatal corticosteroids was associated with a significantly lower risk of neurodevelopmental impairment in children with extremely preterm birth but a significantly higher risk of adverse neurocognitive and/or psychological outcomes in children with late-preterm and full-term birth, who made up approximately half of those with exposure to antenatal corticosteroids. The findings suggest a need for caution in administering antenatal corticosteroids.
Topics: Adrenal Cortex Hormones; Female; Humans; Odds Ratio; Pregnancy; Premature Birth
PubMed: 35404395
DOI: 10.1001/jamapediatrics.2022.0483