Maria Regina Torloni

The Increasing Trend in Caesarean Section Rates: Global, Regional and National Estimates: 1990-2014

Background Caesarean section (CS) rates continue to evoke worldwide concern because of their steady increase, lack of consensus on the appropriate CS rate and the associated additional short- and long-term risks and costs. We present the latest CS rates and trends over the last 24 years. Methods We collected nationally-representative data on CS rates between 1990 to 2014 and calculated regional and subregional weighted averages. We conducted a longitudinal analysis calculating differences in CS rates as absolute change and as the average annual rate of increase (AARI). Results According to the latest data from 150 countries, currently 18.6% of all births occur by CS, ranging from 6% to 27.2% in the least and most developed regions, respectively. Latin America and the Caribbean region has the highest CS rates (40.5%), followed by Northern America (32.3%), Oceania (31.1%), Europe (25%), Asia (19.2%) and Africa (7.3%). Based on the data from 121 countries, the trend analysis showed that between 1990 and 2014, the global average CS rate increased 12.4% (from 6.7% to 19.1%) with an average annual rate of increase of 4.4%. The largest absolute increases occurred in Latin America and the Caribbean (19.4%, from 22.8% to 42.2%), followed by Asia (15.1%, from 4.4% to 19.5%), Oceania (14.1%, from 18.5% to 32.6%), Europe (13.8%, from 11.2% to 25%), Northern America (10%, from 22.3% to 32.3%) and Africa (4.5%, from 2.9% to 7.4%). Asia and Northern America were the regions with the highest and lowest average annual rate of increase (6.4% and 1.6%, respectively). Conclusion The use of CS worldwide has increased to unprecedented levels although the gap between higher- and lower-resource settings remains. The information presented is essential to inform policy and global and regional strategies aimed at optimizing the use of CS.

Gestational diabetes and pregnancy outcomes - a systematic review of the World Health Organization (WHO) and the International Association of Diabetes in Pregnancy Study Groups (IADPSG) diagnostic criteria

BackgroundTwo criteria based on a 2 h 75 g OGTT are being used for the diagnosis of gestational diabetes (GDM), those recommended over the years by the World Health Organization (WHO), and those recently recommended by the International Association for Diabetes in Pregnancy Study Group (IADPSG), the latter generated in the HAPO study and based on pregnancy outcomes. Our aim is to systematically review the evidence for the associations between GDM (according to these criteria) and adverse outcomes.MethodsWe searched relevant studies in MEDLINE, EMBASE, LILACS, the Cochrane Library, CINHAL, WHO-Afro library, IMSEAR, EMCAT, IMEMR and WPRIM. We included cohort studies permitting the evaluation of GDM diagnosed by WHO and or IADPSG criteria against adverse maternal and perinatal outcomes in untreated women. Only studies with universal application of a 75 g OGTT were included. Relative risks (RRs) and their 95% confidence intervals (CI) were obtained for each study. We combined study results using a random-effects model. Inconsistency across studies was defined by an inconsistency index (I2) > 50%.ResultsData were extracted from eight studies, totaling 44,829 women. Greater risk of adverse outcomes was observed for both diagnostic criteria. When using the WHO criteria, consistent associations were seen for macrosomia (RR = 1.81; 95%CI 1.47-2.22; p < 0.001); large for gestational age (RR = 1.53; 95%CI 1.39-1.69; p < 0.001); perinatal mortality (RR = 1.55; 95% CI 0.88-2.73; p = 0.13); preeclampsia (RR = 1.69; 95%CI 1.31-2.18; p < 0.001); and cesarean delivery (RR = 1.37;95%CI 1.24-1.51; p < 0.001). Less data were available for the IADPSG criteria, and associations were inconsistent across studies (I2 ≥ 73%). Magnitudes of RRs and their 95%CIs were 1.73 (1.28-2.35; p = 0.001) for large for gestational age; 1.71 (1.38-2.13; p < 0.001) for preeclampsia; and 1.23 (1.01-1.51; p = 0.04) for cesarean delivery. Excluding either the HAPO or the EBDG studies minimally altered these associations, but the RRs seen for the IADPSG criteria were reduced after excluding HAPO.ConclusionsThe WHO and the IADPSG criteria for GDM identified women at a small increased risk for adverse pregnancy outcomes. Associations were of similar magnitude for both criteria. However, high inconsistency was seen for those with the IADPSG criteria. Full evaluation of the latter in settings other than HAPO requires additional studies.

Classifications for Cesarean Section: A Systematic Review

Background Rising cesarean section (CS) rates are a major public health concern and cause worldwide debates. To propose and implement effective measures to reduce or increase CS rates where necessary requires an appropriate classification. Despite several existing CS classifications, there has not yet been a systematic review of these. This study aimed to 1) identify the main CS classifications used worldwide, 2) analyze advantages and deficiencies of each system. Methods and Findings Three electronic databases were searched for classifications published 1968–2008. Two reviewers independently assessed classifications using a form created based on items rated as important by international experts. Seven domains (ease, clarity, mutually exclusive categories, totally inclusive classification, prospective identification of categories, reproducibility, implementability) were assessed and graded. Classifications were tested in 12 hypothetical clinical case-scenarios. From a total of 2948 citations, 60 were selected for full-text evaluation and 27 classifications identified. Indications classifications present important limitations and their overall score ranged from 2–9 (maximum grade = 14). Degree of urgency classifications also had several drawbacks (overall scores 6–9). Woman-based classifications performed best (scores 5–14). Other types of classifications require data not routinely collected and may not be relevant in all settings (scores 3–8). Conclusions This review and critical appraisal of CS classifications is a methodologically sound contribution to establish the basis for the appropriate monitoring and rational use of CS. Results suggest that women-based classifications in general, and Robsons classification, in particular, would be in the best position to fulfill current international and local needs and that efforts to develop an internationally applicable CS classification would be most appropriately placed in building upon this classification. The use of a single CS classification will facilitate auditing, analyzing and comparing CS rates across different settings and help to create and implement effective strategies specifically targeted to optimize CS rates where necessary.

Maternal BMI and preterm birth: A systematic review of the literature with meta-analysis

Objectives. To examine the association between high prepregnancy maternal body mass index (BMI) and the risk of preterm birth (PTB). Methods. A systematic review of the literature. We included cohorts and case-control studies published since 1968 that examined the association between BMI and PTB of all types, spontaneous (s), elective and with ruptured membranes (PPROM) in three gestational age categories: general (<37 weeks), moderate (32–36 weeks) and very (<32 weeks) PTB. Results. 20,401 citations were screened and 39 studies (1,788,633 women) were included. Preobese (BMI, 25–29.9) and obese I (BMI, 30–34.9) women have a reduced risk for sPTB: AOR = 0.85 (95% CI: 0.80–0.92) and 0.83 (95% CI: 0.75–0.92), respectively. Their risk for moderate PTB was 1.20 (95% CI: 1.04–1.38) and 1.60 (95% CI: 1.32–1.94), respectively. Obese II women (BMI, 35–40) have an increased risk for PTB in general (AOR = 1.33, 95% CI: 1.12–1.57) moderate (AOR = 2.43, 95% CI: 1.46–4.05) and very PTB (AOR = 1.96, 95% CI: 1.66–2.31). Obese III women (BMI > 40) have an even higher risk for very PTB (AOR = 2.27, 95%CI: 1.76–2.94). High BMI does not modify the risk for PPROM and increases the risk for elective PTB. Conclusions. High maternal BMI may have different effects on different types of PTB.

Use of the Robson classification to assess caesarean section trends in 21 countries: a secondary analysis of two WHO multicountry surveys

BACKGROUND Rates of caesarean section surgery are rising worldwide, but the determinants of this increase, especially in low-income and middle-income countries, are controversial. In this study, we aimed to analyse the contribution of specific obstetric populations to changes in caesarean section rates, by using the Robson classification in two WHO multicountry surveys of deliveries in health-care facilities. The Robson system classifies all deliveries into one of ten groups on the basis of five parameters: obstetric history, onset of labour, fetal lie, number of neonates, and gestational age. METHODS We studied deliveries in 287 facilities in 21 countries that were included in both the WHO Global Survey of Maternal and Perinatal Health (WHOGS; 2004-08) and the WHO Multi-Country Survey of Maternal and Newborn Health (WHOMCS; 2010-11). We used the data from these surveys to establish the average annual percentage change (AAPC) in caesarean section rates per country. Countries were stratified according to Human Development Index (HDI) group (very high/high, medium, or low) and the Robson criteria were applied to both datasets. We report the relative size of each Robson group, the caesarean section rate in each Robson group, and the absolute and relative contributions made by each to the overall caesarean section rate. FINDINGS The caesarean section rate increased overall between the two surveys (from 26.4% in the WHOGS to 31.2% in the WHOMCS, p=0.003) and in all countries except Japan. Use of obstetric interventions (induction, prelabour caesarean section, and overall caesarean section) increased over time. Caesarean section rates increased across most Robson groups in all HDI categories. Use of induction and prelabour caesarean section increased in very high/high and low HDI countries, and the caesarean section rate after induction in multiparous women increased significantly across all HDI groups. The proportion of women who had previously had a caesarean section increased in moderate and low HDI countries, as did the caesarean section rate in these women. INTERPRETATION Use of the Robson criteria allows standardised comparisons of data across countries and timepoints and identifies the subpopulations driving changes in caesarean section rates. Women who have previously had a caesarean section are an increasingly important determinant of overall caesarean section rates in countries with a moderate or low HDI. Strategies to reduce the frequency of the procedure should include avoidance of medically unnecessary primary caesarean section. Improved case selection for induction and prelabour caesarean section could also reduce caesarean section rates. FUNDING None.

Safety of ultrasonography in pregnancy : WHO systematic review of the literature and meta-analysis

In the context of the planned International Society of Ultrasound in Obstetrics and Gynecology–World Health Organization multicenter study for the development of fetal growth standards for international application, we conducted a systematic review and meta‐analysis to evaluate the safety of human exposure to ultrasonography in pregnancy.

Biomarkers of Spontaneous Preterm Birth: An Overview of The Literature in the Last Four Decades

Background: Understanding spontaneous preterm birth ([PTB] < 37 weeks) is difficult due to heterogeneities associated with multitudes of risk factors and pathophysiological pathways. Several biomarkers are routinely used clinically for predicting preterm labor; however, these factors are either nonspecific or detected too late. Objective: Systematic review of literature on PTB biomarkers in the last 40 years to map out the existing knowledge and gaps in understanding PTB biomarkers. Search strategies: Five electronic databases were searched for human studies on PTB biomarkers published in any language between 1965 and 2008. Selection criteria: The phenotype of interest for final data extraction was exclusively spontaneous PTB with no rupture of membranes. Data extraction included (a) general characteristics of the study (clinical setting, period, and study design), (b) study/participant characteristics (inclusion and exclusion criteria, race/ethnicity, number of participants, gestational age at sampling, (c) characteristics of the biomarker (type, rationale for its selection, type of biological sample, and assay used, and (d) concentration of biomarkers in cases and controls. Data collection and analysis: The search yielded 7255 citations and data were extracted from 217 articles which met our inclusion and exclusion criteria. Main results: A total of 116 different biomarkers were reported and these were assayed 578 times in the 217 included studies. Over two thirds of the 217 studies were performed on North American or European populations. No reliable biomarkers emerged as a risk predictor of PTB. Conclusions: Identifying similar studies on biomarkers for the prediction of PTB was a very challenging task due heterogeneities in study design, sampling issues (types, timing and processing), assay methods, and analyses. Major areas of concern identified in this review include poor phenotype definition, nonideal study designs and poor rationale for biomarker selection and assays and population stratification issues.

What is the optimal rate of caesarean section at population level? A systematic review of ecologic studies

In 1985, WHO stated that there was no justification for caesarean section (CS) rates higher than 10–15 % at population-level. While the CS rates worldwide have continued to increase in an unprecedented manner over the subsequent three decades, concern has been raised about the validity of the 1985 landmark statement. We conducted a systematic review to identify, critically appraise and synthesize the analyses of the ecologic association between CS rates and maternal, neonatal and infant outcomes. Four electronic databases were searched for ecologic studies published between 2000 and 2014 that analysed the possible association between CS rates and maternal, neonatal or infant mortality or morbidity. Two reviewers performed study selection, data extraction and quality assessment independently. We identified 11,832 unique citations and eight studies were included in the review. Seven studies correlated CS rates with maternal mortality, five with neonatal mortality, four with infant mortality, two with LBW and one with stillbirths. Except for one, all studies were cross-sectional in design and five were global analyses of national-level CS rates versus mortality outcomes. Although the overall quality of the studies was acceptable; only two studies controlled for socio-economic factors and none controlled for clinical or demographic characteristics of the population. In unadjusted analyses, authors found a strong inverse relationship between CS rates and the mortality outcomes so that maternal, neonatal and infant mortality decrease as CS rates increase up to a certain threshold. In the eight studies included in this review, this threshold was at CS rates between 9 and 16 %. However, in the two studies that adjusted for socio-economic factors, this relationship was either weakened or disappeared after controlling for these confounders. CS rates above the threshold of 9–16 % were not associated with decreases in mortality outcomes regardless of adjustments. Our findings could be interpreted to mean that at CS rates below this threshold, socio-economic development may be driving the ecologic association between CS rates and mortality. On the other hand, at rates higher than this threshold, there is no association between CS and mortality outcomes regardless of adjustment. The ecological association between CS rates and relevant morbidity outcomes needs to be evaluated before drawing more definite conclusions at population level.

Effectiveness of gestational diabetes treatment: a systematic review with quality of evidence assessment.

AIMS To evaluate the effectiveness of gestational diabetes (GDM) treatment compared to usual antenatal care, in the prevention of adverse pregnancy outcomes. Additionally, to assess the quality of the evidence to support GDM treatment according to GRADE guidelines. METHODS Fourteen electronic databases and reference lists of relevant literature were searched for articles published from inception to February, 2012. Controlled clinical trials comparing GDM treatment to usual antenatal care were included. Independent extraction of articles was done by two authors using predefined data fields. RESULTS Seven trials involving 3157 women were included. We found high quality evidence that treatment of GDM reduces macrosomia (RR=0.47; 95% CI, 0.34-0.65; NNT=11.4) and large for gestational age birth (RR=0.57; 95% CI, 0.47-0.71; NNT=12.2); moderate quality evidence that treatment reduces preeclampsia (RR=0.61; 95% CI, 0.46-0.81; NNT=21.0) and hypertensive disorders in pregnancy (RR=0.64; 95% CI, 0.51-0.81; NNT=18.1); and low quality evidence that treatment reduces shoulder dystocia (RR=0.41; 95% CI, 0.22-0.76; NNT=48.8). No statistically significant reduction was seen for caesarean section. No increase in small for gestational age or preterm birth was found. CONCLUSIONS Treatment of GDM is effective in reducing macrosomia (high quality evidence), preeclampsia and shoulder dystocia.

A systematic review of the Robson classification for caesarean section: what works, doesn't work and how to improve it.

Background Caesarean sections (CS) rates continue to increase worldwide without a clear understanding of the main drivers and consequences. The lack of a standardized internationally-accepted classification system to monitor and compare CS rates is one of the barriers to a better understanding of this trend. The Robsons 10-group classification is based on simple obstetrical parameters (parity, previous CS, gestational age, onset of labour, fetal presentation and number of fetuses) and does not involve the indication for CS. This classification has become very popular over the last years in many countries. We conducted a systematic review to synthesize the experience of users on the implementation of this classification and proposed adaptations. Methods Four electronic databases were searched. A three-step thematic synthesis approach and a qualitative metasummary method were used. Results 232 unique reports were identified, 97 were selected for full-text evaluation and 73 were included. These publications reported on the use of Robsons classification in over 33 million women from 31 countries. According to users, the main strengths of the classification are its simplicity, robustness, reliability and flexibility. However, missing data, misclassification of women and lack of definition or consensus on core variables of the classification are challenges. To improve the classification for local use and to decrease heterogeneity within groups, several subdivisions in each of the 10 groups have been proposed. Group 5 (women with previous CS) received the largest number of suggestions. Conclusions The use of the Robson classification is increasing rapidly and spontaneously worldwide. Despite some limitations, this classification is easy to implement and interpret. Several suggested modifications could be useful to help facilities and countries as they work towards its implementation.