Global inequities in cesarean section deliveries and required resources persist.

OBJECTIVE: The purpose of this study was to estimate the global distribution and financial cost associated with the inequities present in the use of cesarean sections (CS) worldwide. STUDY DESIGN: We used the latest estimates on CS rates published by WHO and we adopted 10-15 % as the range of CS rates that are considered optimal for adequate use. We calculated the cost (in USD) to achieve CS rates of 10-15 % for countries that reported rates below 10 %. We also calculated the cost of CS rates in excess (>15 % and > 20 %) by estimating how much it would cost to reduce the rates to 10-15 % for each of those countries. RESULTS: 137 countries are included in this analysis with updated data on CS rates between the years 2010 and 2018. Our analysis found that 36 countries reported CS rates < 10 %, whereas 91 countries reported CS rates > 15 % (a majority of which were > 20 %); only 10 countries reported CS rates between 10 and 15 %. The cost of CS exceeding a rate of 15 % is estimated to be $9,586,952,466 including inflation and exceeding 20 % is $7.169.248.033 (USD). The cost of achieving "needed" CS among countries with CS rates < 10 % is $612,609,418 (USD). The cost of cesarean sections exceeding 15 % has increased by 313 % between 2008 and more recent years, accruing $7 billion (USD) more in surplus since 2008. The reallocation of CS funding would save the global economy $9 billion (USD). CONCLUSION: Global inequities in CS performed and associated costs have increased since 2008, resulting in a disproportionate number of resources allocated.

Optimizing the use of cesarean section in Argentina: design and methodology of a formative research for the development of interventions.

BACKGROUND: While cesarean section is an essential life-saving strategy for women and newborns, its current overuse constitutes a global problem. The aim of this formative research is to collect information from hospitals, health professionals and women regarding the use of cesarean section in Argentina. This article describes the methodology of the study, the characteristics of the hospitals and the profile of the participants. METHODS: This formative research is a mixed-method study that will be conducted in seven provinces of Argentina. The eligibility criteria for the hospitals are (a) use of the Perinatal Information System, (b) cesarean section rate higher than 27% in 2016, (c) ≥ 1000 deliveries per year. Quantitative and qualitative research techniques will be used for data collection and analysis. The main inquiry points are the determining factors for the use of cesarean section, the potential interventions to optimize the use of cesarean section and, in the case of women, their preferred type of delivery. DISCUSSION: It is expected that the findings will provide a situation diagnosis to help a context-sensitive implementation of the interventions recommended by the World Health Organization to optimize cesarean section use. Trial registration IS002316 Cesarean section is an essential medical tool for mothers and their children, but nowadays its overuse is a problem worldwide. Our purpose is to get information from hospitals, health professionals and women about how cesarean section is used in Argentina. In this protocol we describe how we will carry out the study and the characteristics of the hospitals and participants. We will implement this study in seven provinces of Argentina, in hospitals that have more than 1,000 births each year, had a cesarean section rate higher than 27% in 2016 and use the Perinatal Information System. We will gather information using forms, surveys and interviews. We want to identify the factors that decide the use of a cesarean section, the potential interventions that can improve the use of cesarean section and, in the case of women, the type of delivery they prefer. We expect that this study will give us a diagnosis of how cesarean section is used in Argentina, and that this will help to apply the interventions that the World Health Organization recommends to optimize the use of cesarean section in our specific context.

RESUMEN: INTRODUCCIóN: Aun cuando la cesárea es una intervención que puede ser esencial para salvar la vida de una mujer y su hijo, el crecimiento excesivo de su uso  es un problema global. El propósito de esta investigación formativa es recolectar información sobre las instituciones, profesionales de la salud y mujeres acerca del uso de la cesárea en la Argentina. Este artículo describe la metodología del estudio, las características de los hospitales y el perfil de los participantes. METODOLOGíA: Esta investigación formativa usa un diseño mixto aplicado en siete provincias del país. Los criterios de elegibilidad para los hospitales son: (a) uso del Sistema Informático Perinatal, (b) tasa de cesáreas mayor al 27% en 2016, y (c) ≥ 1000 partos por año. Se usarán técnicas cualitativas y cuantitativas para la recolección de datos y el análisis. Los principales temas a indagar son los determinantes del uso de la cesárea, las intervenciones para optimizar su uso y, en el caso de las mujeres, sus preferencias sobre el modo de parto. DISCUSIóN: Se espera que los resultados den lugar a un diagnóstico de situación que permita una implementación de las intervenciones propuesas por la OMS para optimizar el uso de la cesárea más ajustada al contexto. Registro del estudio IS002316.

Analgesia for vaginal birth: Secondary analysis from the WHO Multicountry Survey on Maternal and Newborn Health.

OBJECTIVE: To evaluate the use of analgesia during labor in women who had a vaginal birth and to determine the factors associated with its use. METHODS: A secondary analysis was performed of the WHO Multicountry Survey on Maternal and Newborn Health, a cross-sectional, facility-based survey including 359 healthcare facilities in 29 countries. The prevalence of analgesia use for vaginal birth in different countries was reported according to the Human Development Index (HDI). Sociodemographic and obstetric characteristics of the participants with and without analgesia were compared. The prevalence ratios were compared across countries, HDI groups, and regions using a design-based χ2 test. RESULTS: Among the 221 345 women who had a vaginal birth, only 4% received labor analgesia, mainly epidural. The prevalence of women receiving analgesia was significantly higher in countries with a higher HDI than in countries with a lower HDI. Education was significantly associated with increased use of analgesia; nulliparous women and women undergoing previous cesarean delivery had a significantly increased likelihood of receiving analgesia. CONCLUSION: Use of analgesia for women undergoing labor and vaginal delivery was low, specifically in low-HDI countries. Whether low use of analgesia reflects women's desire or an unmet need for pain relief requires further studies.

Interpregnancy interval and hypertensive disorders of pregnancy: A population-based cohort study.

BACKGROUND: Despite extensive research on risk factors and mechanisms, the extent to which interpregnancy interval (IPI) affects hypertensive disorders of pregnancy in high-income countries remains unclear. OBJECTIVES: To examine the association between IPI and hypertensive disorders of pregnancy in a high-income country setting using both within-mother and between-mother comparisons. METHODS: A retrospective population-based cohort study was conducted among 103 909 women who delivered three or more consecutive singleton births (n = 358 046) between 1980 and 2015 in Western Australia. We used conditional Poisson regression with robust variance, matching intervals of the same mother and adjusted for factors that vary within-mother across pregnancies, to investigate the association between IPI categories (reference 18-23 months), and the risk of hypertensive disorders of pregnancy. For comparison with previous studies, we also applied unmatched Poisson regression (between-mother analysis). RESULTS: The incidence of preeclampsia and gestational hypertension during the study period was 4%, and 2%, respectively. For the between-mother comparison, mothers with intervals of 6-11 months had lower risk of preeclampsia with adjusted relative risk (RR) 0.92 (95% confidence interval [CI] 0.85, 0.98) compared to reference category of 18-23 months. With the within-mother matched design, we estimated a larger effect of long IPI on risk of preeclampsia (RR 1.29, 95% CI 1.18, 1.42 for 60-119 months; and RR 1.30, 95% CI 1.10, 1.53 for intervals ≥120 months) compared to 18-23 months. Short IPIs were not associated with hypertensive disorders of pregnancy. CONCLUSIONS: In our cohort, longer IPIs were associated with increased risk of preeclampsia. However, there was insufficient evidence to suggest that short IPIs (<6 months) increase the risks of hypertensive disorders of pregnancy.

Effect of interpregnancy interval on gestational diabetes: a retrospective matched cohort study.

PURPOSE: To examine the association between interpregnancy interval (IPI) and gestational diabetes using both within-mother and between-mother comparisons. METHODS: A retrospective cohort study of 103,909 women who delivered three or more consecutive singleton births (n = 358,046) between 1 January 1980 and 31 December 2015 in Western Australia. The association between IPI and gestational diabetes was estimated using conditional logistic regression, matching pregnancies to the same mother and adjusted for factors that vary within-mother across pregnancies. For comparison with previous studies, we also applied unmatched logistic regression (between-mother analysis). RESULTS: The conventional between-mother analysis resulted in adjusted odds ratios (aOR) of 1.13 (95% CI, 1.06-1.21) for intervals of 24-59 months and 1.51 (95% CI, 1.33-1.70) for intervals of 120 or more months, compared with IPI of 18-23 months. In addition, short IPIs were associated with lower odds of gestational diabetes with (aOR: 0.89; 95% CI, 0.82-0.97) for 6-11 months and (aOR: 0.92; 95% CI, 0.85-0.99) for 12-17-month. In comparison, the adjusted within-mother matched analyses showed no statistically significant association between IPIs and gestational diabetes. All effect estimates were attenuated using the within-mother matched model. CONCLUSION: Our findings do not support the hypothesis that short IPI (<6 months) increases the risk of gestational diabetes and suggest that observed associations in previous research might be attributable to confounders that vary between mothers.

Analgesia during Labor and Vaginal Birth among Women with Severe Maternal Morbidity: Secondary Analysis from the WHO Multicountry Survey on Maternal and Newborn Health.

AIM: To evaluate the use of analgesia for vaginal birth, in women with and without severe maternal morbidity (SMM) and to describe sociodemographic, clinical, and obstetric characteristics and maternal and perinatal outcomes associated with labor analgesia. METHODS: Secondary analysis of the WHO Multicountry Survey on Maternal and Newborn Health (WHO-MCS), a global cross-sectional study performed between May 2010 and December 2011 in 29 countries. Women who delivered vaginally and had an SMM were included in this analysis and were then divided into two groups: those who received and those who did not receive analgesia for labor/delivery. We further compared maternal characteristics and maternal and perinatal outcomes between these two groups. RESULTS: From 314,623 women originally included in WHO-MCS, 9,788 developed SMM and delivered vaginally, 601 (6.1%) with analgesia and 9,187 (93.9%) without analgesia. Women with SMM were more likely to receive analgesia than those who did not experience SMM. Global distribution of SMM was similar; however, the use of analgesia was less prevalent in Africa. Higher maternal education, previous cesarean section, and nulliparity were factors associated with analgesia use. Analgesia was not an independent factor associated with an increase of severe maternal outcome (Maternal Near Miss + Maternal Death). CONCLUSIONS: The overall use of analgesia for vaginal delivery is low but women with SMM are more likely to receive analgesia during labor. Social conditions are closely linked with the likelihood of having analgesia during delivery and such a procedure is not associated with increased adverse maternal outcomes. Expanding the availability of analgesia in different levels of care should be a concern worldwide.

Maternal clinical predictors of preterm birth in twin pregnancies: A systematic review involving 2,930,958 twin pregnancies.

In twin pregnancies, which are at high risk of preterm birth, it is not known if maternal clinical characteristics pose additional risks. We undertook a systematic review to assess the risk of both spontaneous and iatrogenic early (<34 weeks) or late preterm birth (<37 weeks) in twin pregnancies based on maternal clinical predictors. We searched the electronic databases from January 1990 to November 2017 without language restrictions. We included studies on women with monochorionic or dichorionic twin pregnancies that evaluated clinical predictors and preterm births. We reported our findings as odds ratio (OR) with 95% confidence intervals (CI) and pooled the estimates using random-effects meta-analysis for various predictor thresholds. From 12, 473 citations, we included 59 studies (2,930,958 pregnancies). The risks of early preterm birth in twin pregnancies were significantly increased in women with a previous history of preterm birth (OR 2.67, 95% CI 2.16-3.29, I2 = 0%), teenagers (OR 1.81, 95% CI 1.68-1.95, I2 = 0%), BMI > 35 (OR 1.63, 95% CI 1.30-2.05, I2 = 52%), nulliparous (OR 1.51, 95% CI 1.38-1.65, I2 = 73%), non-white vs. white (OR 1.31, 95% CI 1.20-1.43, I2 = 0%), black vs. non-black (OR 1.38, 95% CI 1.07-1.77, I2 = 98%), diabetes (OR 1.73, 95% CI 1.29-2.33, I2 = 0%) and smokers (OR 1.30, 95% CI 1.23-1.37, I2 = 0%). The odds of late preterm birth were also increased in women with history of preterm birth (OR 3.08, 95% CI 2.10-4.51, I2 = 73%), teenagers (OR 1.36, 95% CI 1.18-1.57, I2 = 57%), BMI > 35 (OR 1.18, 95% CI 1.02-1.35, I2 = 46%), nulliparous (OR 1.41, 95% CI 1.23-1.62, I2 = 68%), diabetes (OR 1.44, 95% CI 1.05-1.98, I2 = 55%) and hypertension (OR 1.49, CI 1.20-1.86, I2 = 52%). The additional risks posed by maternal clinical characteristics for early and late preterm birth should be taken into account while counseling and managing women with twin pregnancies.

Systematic review and meta-analysis of studies on delivery preferences in Brazil.

BACKGROUND: Cesarean delivery rates in Brazil are among the highest in the world. User preference is often mentioned as an important factor driving this. OBJECTIVES: To identify, appraise, and synthesize the results of studies into delivery preferences in Brazil. SEARCH STRATEGY: MEDLINE, LILACS, and PsycINFO databases were searched, without language restrictions, using "delivery" and "preference" from inception to November 4, 2017. SELECTION CRITERIA: Cross-sectional or cohort studies with quantitative data on delivery preferences of lay persons in Brazil. DATA COLLECTION AND ANALYSIS: Two reviewers performed study selection, quality assessment, and data extraction. A meta-analysis of proportions with a preference for cesarean delivery was performed, including subgroups analyses. MAIN RESULTS: There were 28 studies with 31 071 participants included. The overall prevalence of preference for cesarean delivery was 27.2% (95% confidence interval [CI] 26.7%-27.7%; 28 studies, n=31 071). Cesarean delivery preference was higher among multiparas with previous cesarean deliveries (58.0%, 95% CI 56.6%-59.3%; nine studies, n=5542) than among multiparas without prior cesarean deliveries (17.3%, 95% CI 16.4%-18.2%; eight studies, n=7903), and among women with private health insurance (44.3%, 95% CI 43.0%-45.6%; nine studies, n=6048) than among those who depended on the public healthcare system (22.7%, 95% CI 22.2%-23.3%; 20 studies, n=24 314). CONCLUSIONS: Overall, most lay persons in Brazil did not prefer to deliver by cesarean.

Cesarean rates and severe maternal and neonatal outcomes according to the Robson 10-Group Classification System in Khon Kaen Province, Thailand.

OBJECTIVE: To assess cesarean rates and maternal and neonatal outcomes in each group in the Robson 10-Group Classification System (TGCS). METHODS: In a cross-sectional study, data were reviewed from all pregnant women who delivered at 24 government hospitals in Khon Kaen Province, Thailand, in 2014. Delivery and perinatal outcomes were recorded. RESULTS: Of 18 043 deliveries, 5666 (31.4%) were by cesarean. Women in group 5 (previous cesarean) accounted for the most cesareans (1472, 26.0%). Groups 1 and 2 (nulliparous women) accounted for 2355 (41.6%) of procedures; the rate of cesarean within these two groups was 19.4% (1162/5981) and 71.2% (1193/1675), respectively. As compared with group 1, women in groups 2, 4, 6, 7, and 10 had significantly increased risk of severe maternal outcomes, and those in groups 6, 7, 8, 9, and 10 had an increased risk of severe neonatal outcomes. CONCLUSION: The rate of cesarean in the study setting was high, and three out of four procedures were performed for women in groups 5, 1, and 2. Interventions should be focused on these groups to reduce the overall cesarean rates.

Elective cesarean section for women living with HIV: a systematic review of risks and benefits.

OBJECTIVE AND DESIGN: To inform WHO guidelines, we conducted a systematic review and meta-analysis to assess maternal and perinatal outcomes comparing cesarean section (c-section) before labor and rupture of membranes [elective c-section (ECS)] with other modes of delivery for women living with HIV. METHODS: We searched PubMed, CINAHL, Embase, CENTRAL, and previous reviews to identify published trials and observational studies through October 2015. Results were synthesized using random-effects meta-analysis, stratifying for combination antiretroviral therapy (cART), CD4/viral load (VL), delivery at term, and low-income/middle-income countries. RESULTS: From 2567 citations identified, 36 articles met inclusion criteria. The single randomized trial, published in 1999, reported minimal maternal morbidity and significantly fewer infant HIV infections with ECS [odds ratio (OR) 0.2, 95% confidence interval (CI) 0.0-0.5]. Across observational studies, ECS was associated with increased maternal morbidity compared with vaginal delivery (OR 3.12, 95% CI 2.21-4.41). ECS was also associated with decreased infant HIV infection overall (OR 0.43, 95% CI 0.30-0.63) and in low-income/middle-income countries (OR 0.27, 95% CI 0.16-0.45), but not among women on cART (OR 0.82, 95% CI 0.47-1.43) or with CD4 cell count more than 200/VL less than 400/term delivery (OR 0.59, 95% CI 0.21-1.63). Infant morbidity moderately increased with ECS. CONCLUSION: Although ECS may reduce infant HIV infection, this effect was not statistically significant in the context of cART and viral suppression. As ECS poses other risks, routine ECS for all women living with HIV may not be appropriate. Risks and benefits will differ across settings, depending on underlying risks of ECS complications and vertical transmission during delivery. Understanding individual client risks and benefits and respecting women's autonomy remain important.

Inequities in the use of cesarean section deliveries in the world.

OBJECTIVE: The purpose of this study was to describe the unequal distribution in the performance of cesarean section delivery (CS) in the world and the resource-use implications of such inequity. STUDY DESIGN: We obtained data on the number of CSs performed in 137 countries in 2008. The consensus is that countries should achieve a 10% rate of CS; therefore, for countries that are below that rate, we calculated the cost to achieve a 10% rate. For countries with a CS rate of >15%, we calculated the savings that could be made by the achievement of a 15% rate. RESULTS: Fifty-four countries had CS rates of <10%, whereas 69 countries showed rates of >15%. The cost of the global saving by a reduction of CS rates to 15% was estimated to be $2.32 billion (US dollars); the cost to attain a 10% CS rate was $432 million (US dollars). CONCLUSION: CSs that are potentially medically unjustified appear to command a disproportionate share of global economic resources.

The role of faith-based organizations in maternal and newborn health care in Africa.

BACKGROUND: Global disparities in maternal and newborn health represent one of the starkest health inequities of our times. Faith-based organizations (FBOs) have historically played an important role in providing maternal/newborn health services in African countries. However, the contribution of FBOs in service delivery is insufficiently recognized and mapped. OBJECTIVES: A systematic review of the literature to assess available evidence on the role of FBOs in the area of maternal/newborn health care in Africa. SEARCH STRATEGY: MEDLINE and EMBASE were searched for articles published between 1989 and 2009 on maternal/newborn health and FBOs in Africa. RESULTS: Six articles met the criteria for inclusion. These articles provided information on 6 different African countries. Maternal/newborn health services provided by FBOs were similar to those offered by governments, but the quality of care received and the satisfaction were reported to be better. CONCLUSION: Efforts to document and analyze the contribution of FBOs in maternal/newborn health are necessary to increase the recognition of FBOs and to establish stronger partnerships with them in Africa as an untapped route to achieving Millennium Development Goals 4 and 5.

WHO global survey on maternal and perinatal health in Latin America: classifying caesarean sections.

BACKGROUND: Caesarean section rates continue to increase worldwide with uncertain medical consequences. Auditing and analysing caesarean section rates and other perinatal outcomes in a reliable and continuous manner is critical for understanding reasons caesarean section changes over time. METHODS: We analyzed data on 97,095 women delivering in 120 facilities in 8 countries, collected as part of the 2004-2005 Global Survey on Maternal and Perinatal Health in Latin America. The objective of this analysis was to test if the "10-group" or "Robson" classification could help identify which groups of women are contributing most to the high caesarean section rates in Latin America, and if it could provide information useful for health care providers in monitoring and planning effective actions to reduce these rates. RESULTS: The overall rate of caesarean section was 35.4%. Women with single cephalic pregnancy at term without previous caesarean section who entered into labour spontaneously (groups 1 and 3) represented 60% of the total obstetric population. Although women with a term singleton cephalic pregnancy with a previous caesarean section (group 5) represented only 11.4% of the obstetric population, this group was the largest contributor to the overall caesarean section rate (26.7% of all the caesarean sections). The second and third largest contributors to the overall caesarean section rate were nulliparous women with single cephalic pregnancy at term either in spontaneous labour (group 1) or induced or delivered by caesarean section before labour (group 2), which were responsible for 18.3% and 15.3% of all caesarean deliveries, respectively. CONCLUSION: The 10-group classification could be easily applied to a multicountry dataset without problems of inconsistencies or misclassification. Specific groups of women were clearly identified as the main contributors to the overall caesarean section rate. This classification could help health care providers to plan practical and effective actions targeting specific groups of women to improve maternal and perinatal care.

Cesarean delivery surveillance system at a maternity hospital in Kabul, Afghanistan.

OBJECTIVE: To use an active facility-based maternal and newborn surveillance system to describe cesarean delivery practices and outcomes in a resource-poor setting. METHODS: Using data from operating room logbooks, 392 cesarean deliveries were evaluated between April 1 and June 30 2006 at a large public maternity hospital in Kabul, Afghanistan. RESULTS: The perinatal mortality rate was 89 per 1000 births: 57% antepartum and 37% intrapartum stillbirths. Fetuses with normal birth weight comprised 85% of intrapartum stillbirths. Obstructed labor, uterine rupture, and malpresentation accounted for more than 50% of perinatal deaths. The cesarean delivery rate was 10.2% and there were 2 maternal deaths. CONCLUSION: The high percentage of intrapartum stillbirths among normal birth weight fetuses suggests a need for improved labor monitoring and surgical obstetric practices. The use of a facility-based perinatal surveillance system is critical in guiding such quality assurance initiatives.

The introduction of confidential enquiries into maternal deaths and near-miss case reviews in the WHO European Region.

Most maternal deaths can be averted with known, effective interventions but countries require information about which women are dying and why, and what can been done to prevent such deaths in future. This paper describes the introduction of two approaches to reviewing maternal deaths and severe obstetric complications in 12 countries in transition in the WHO European Region - national-level confidential enquiries into maternal deaths and facility-based near-miss case reviews. Initially, two regional meetings involving stakeholders from 12 countries were held in 2004-2005, followed by national meetings in seven of the countries. The Republic of Moldova was the first to pilot the review process, preceded by a technical workshop to make detailed plans, provide training in how to facilitate and carry out a review, finalise clinical guidelines against which the findings of the confidential enquiry and near-miss case review could be judged, and a range of other preparatory work. To date, near-miss case reviews have been carried out in the three main referral hospitals in Moldova, and a national committee appointed by the Ministry of Health to conduct the confidential enquiry has met twice. Several other countries have begun a similar process, but progress may remain slow due to continuing fears of punitive actions against health professionals who have a mother or baby die in their care.

Rates of caesarean section: analysis of global, regional and national estimates.

Rates of caesarean section are of concern in both developed and developing countries. We set out to estimate the proportion of births by caesarean section (CS) at national, regional and global levels, describe regional and subregional patterns and correlate rates with other reproductive health indicators. We analysed nationally representative data available from surveys or vital registration systems on the proportion of births by CS. We used local non-parametric regression techniques to correlate CS with maternal mortality ratio, infant and neonatal mortality rates, and the proportion of births attended by skilled health personnel. Although very unevenly distributed, 15% of births worldwide occur by CS. Latin America and the Caribbean show the highest rate (29.2%), and Africa shows the lowest (3.5%). In developed countries, the proportion of caesarean births is 21.1% whereas in least developed countries only 2% of deliveries are by CS. The analysis suggests a strong inverse association between CS rates and maternal, infant and neonatal mortality in countries with high mortality levels. There is some suggestion of a direct positive association at lower levels of mortality. CS levels may respond primarily to economic determinants.

Analysis of association between maternal tumor necrosis factor-alpha promoter polymorphism (-308), tumor necrosis factor concentration, and preterm birth.

OBJECTIVE: This study was undertaken to investigate the association of tumor necrosis factor-alpha (TNF-alpha) single nucleotide polymorphism (G-308>A) and risk of preterm birth by performing a systematic review and a meta-analysis of available studies. In addition, association between this variant and TNF-alpha concentration in amniotic fluid (AF) in preterm birth was also investigated. STUDY DESIGN: Articles were chosen based on a Medline and EMBASE searches (1990-2005) with no language restrictions. An ongoing case-control study conducted in Nashville, TN, was also included. Articles evaluating the association between G-308>A and preterm birth were screened according to specific inclusion criteria. Meta-analysis was performed by using a random effect model. Association between maternal -308 genotype and AF-TNF-alpha concentration was determined by sandwich immunoassays. RESULTS: Titles and abstracts of 6851 citations identified through the search were screened. Including our own study, a total of 7 studies were included for meta-analysis. Only 2 reported a statistically significant increased risk based on -308 genotype. Meta-analysis of the case-control studies on a pooled dataset (a total of 1846 subjects, 638 cases, and 1208 controls) showed no significant association between the -308 genotype and the risk of preterm birth (odds ratio [OR] 1.41; CI 0.90-2.19). A nonsignificant increase of AF TNF-alpha concentration was demonstrated with the GG genotype in cases compared with the presence of allele A. CONCLUSION: Meta-analysis of available evidence documented no statistically significant association between a single nucleotide polymorphism in the TNF-alpha gene (G-308>A) and preterm birth. Analyses of AF-TNF-alpha concentration demonstrated no increase in TNF-alpha in the presence of the minor allele (A). These results suggest that this single nucleotide polymorphism does not independently associate strongly with preterm birth.

National estimates for maternal mortality: an analysis based on the WHO systematic review of maternal mortality and morbidity.

BACKGROUND: Despite the worldwide commitment to improving maternal health, measuring, monitoring and comparing maternal mortality estimates remain a challenge. Due to lack of data, international agencies have to rely on mathematical models to assess its global burden. In order to assist in mapping the burden of reproductive ill-health, we conducted a systematic review of incidence/prevalence of maternal mortality and morbidity. METHODS: We followed the standard methodology for systematic reviews. This manuscript presents nationally representative estimates of maternal mortality derived from the systematic review. Using regression models, relationships between study-specific and country-specific variables with the maternal mortality estimates are explored in order to assist further modelling to predict maternal mortality. RESULTS: Maternal mortality estimates included 141 countries and represent 78.1% of the live births worldwide. As expected, large variability between countries, and within regions and subregions, is identified. Analysis of variability according to study characteristics did not yield useful results given the high correlation with each other, with development status and region. A regression model including selected country-specific variables was able to explain 90% of the variability of the maternal mortality estimates. Among all country-specific variables selected for the analysis, three had the strongest relationships with maternal mortality: proportion of deliveries assisted by a skilled birth attendant, infant mortality rate and health expenditure per capita. CONCLUSION: With the exception of developed countries, variability of national maternal mortality estimates is large even within subregions. It seems more appropriate to study such variation through differentials in other national and subnational characteristics. Other than region, study of country-specific variables suggests infant mortality rate, skilled birth attendant at delivery and health expenditure per capita are key variables to predict maternal mortality at national level.

Effectiveness of different databases in identifying studies for systematic reviews: experience from the WHO systematic review of maternal morbidity and mortality.

BACKGROUND: Failure to be comprehensive can distort the results of a systematic review. Conversely, extensive searches may yield unmanageable number of citations of which only few may be relevant. Knowledge of usefulness of each source of information may help to tailor search strategies in systematic reviews. METHODS: We conducted a systematic review of prevalence/incidence of maternal mortality and morbidities from 1997 to 2002. The search strategy included electronic databases, hand searching, screening of reference lists, congress abstract books, contacting experts active in the field and web sites from less developed countries. We evaluated the effectiveness of each source of data and discuss limitations and implications for future research on this topic. RESULTS: Electronic databases identified 64098 different citations of which 2093 were included. Additionally 487 citations were included from other sources. MEDLINE had the highest yield identifying about 62% of the included citations. BIOSIS was the most precise with 13.2% of screened citations included. Considering electronic citations alone (2093), almost 20% were identified uniquely by MEDLINE (400), 7.4% uniquely by EMBASE (154), and 5.6% uniquely by LILACS (117). About 60% of the electronic citations included were identified by two or more databases. CONCLUSIONS: This analysis confirms the need for extending the search to other sources beyond well-known electronic databases in systematic reviews of maternal mortality and morbidity prevalence/incidence. These include regional databases such as LILACS and other topic specific sources such as hand searching of relevant journals not indexed in electronic databases. Guidelines for search strategies for prevalence/incidence studies need to be developed.