Concepts , prevalence and characteristics of severe maternal morbidity and near miss in Brazil : a systematic review

Objective: to analyze frequency, characteristics and causes of severe maternal morbidity (maternal near miss) in Brazil. Methods: a systematic review on quantitative studies about characteristics, causes, and associated factors on severe maternal morbidity (maternal near miss). The search was done through MEDLINE (maternal near miss or severe maternal morbidity and Brazil) and LILACS (maternal near miss, maternal morbidity). Data were extracted from methodological characteristics of the article, criteria for maternal morbidity and main results. Near miss ratios and indicators were described and estimated. Results: we identified 48 studies: 37 were on hospital based; six were based on health surveys and five were based on information systems. Different definitions were adopted. Maternal near miss ratio ranged from 2.4/1000 LB to 188.4/1000 LB, depending on the criteria and epidemiological scenario. The mortality rate for maternal near miss varied between 3.3% and 32.2%. Hypertensive diseases and hemorrhage were the most common morbidities, but indirect causes have been increasing. Flaws in the healthcare were associated to near miss and also sociodemographic factors (non-white skin color, adolescence/ age≥ 35 years old, low schooling level). Conclusions: the frequency of maternal near miss in Brazil is high, with a profile of similar causes to maternal mortality. Inequities and delays in the healthcare were identified as association.


Introduction
Women and children health is a worldwide priority, and the losses in puerperal pregnancy period and at childhood are considered devastating for the family and the society.Maternal mortality ratio reflects on the socioeconomic indicators as well as the quality in the offered healthcare, and its decrease in Brazil and in the world was included in the Millennium Goals, and it remains in the Sustainable Development Goals. 1 The previous goal did not achieve its two-thirds reduction on Maternal Mortality Ratio (MMR), and for Brazil, the challenge is to reduce the MMR from 20/100,000 live births until 2030. 1 Despite the high maternal mortality rates, maternal death is an infrequent event in absolute numbers, making local studies and basic causes difficult to understand.In addition, there is a spectrum of morbid conditions between healthy gestation and maternal death ranging from mild to extremely severe conditions. 2 In this context, the World Health Organization (WHO) defined the criterion of severe maternal morbidity or "maternal near miss" as "a woman who almost died but survived a serious maternal complication during pregnancy, childbirth, or within 42 days of completion of pregnancy." 3These women have survived severe maternal complications or "life-threatening conditions" due to adequate healthcare services. 3There is a list of life-threatening conditions (LTC) acknowledged by clinical, laboratorial or even management characteristics that support this classification established by WHO in order to unify the diagnostic criteria. 3rior to WHO, there were other criteria for this outcome, ranging from the admission at the Intensive Care Unit to organ dysfunction, with different accuracy measurements. 4Life-threatening conditions are the extreme of potential life-threatening conditions (PLTC) or maternal complications and that relates to some organ dysfunction feature. 2 Several indicators derived from the near miss concept and can be used in research and obstetrical audits.The maternal near miss ratio (MNMR) refers to the number of maternal near miss cases by the number of live births (by 100,000); severe maternal outcomes (or life-threatening condition) includes cases of near miss and maternal death; maternal near miss mortality ratio and maternal death (MNM: MD); and the mortality rate (MR), which refers to the proportion of maternal deaths from the total sever outcomes.The latter two reflect the effectiveness on care in preventing a severe case evolving in death, and expecting a high MNM: MD and a low MR. 3 In addition to women's commitment, severe maternal morbidity/maternal near miss has an impact on fetal and neonatal outcomes, including neonatal near miss. 5e have not identified reviews on severe maternal morbidity/near miss in Brazil, and the most recent international review published in 2013, included a few Brazilian studies. 6Considering this gap and the relevance that deaths and other maternal outcomes such as abortion, hypertensive diseases, hemorrhages and infections have an effect on women and children's health, the objective of this article was to review Brazilian medical literature on maternal near miss.

Methods
A systematic review of the literature on severe maternal morbidity/maternal near miss in Brazil was carried out, without date restriction and completed search was in October 2016.
Regarding eligibility criteria, we considered two main approaches for articles inclusion on: descriptive studies (description of maternal morbidity/nearmiss rates, description of causes); studies on factors associated to maternal morbidity/near miss outcomes (cross-sectional or longitudinal).
Case reports, studies with specific pathological morbidity groups not directly related to maternal morbidity and mortality and studies where maternal morbidity was the exposure variable and not an outcome, were excluded.
Review studies were initially included to widen the identification of original studies and subsequently were excluded.We also excluded letters, editorials, dissertations and theses, prioritizing fulltext articles already published in scientific journals.We adopted as an exclusion criterion articles in which Brazil was not the only country addressed, in order to emphasize national approaches on the theme.
The bibliographic search was performed using LILACS databases (through Virtual Health Library) and MEDLINE (through PubMed), without language restriction.The terms severe maternal morbidity and near miss still do not exist as descriptors in scientific literature bases.
In LILACS, the search strategy was performed in two stages (the use of Boolean operator OR joining the two terms resulted in a fewer number of articles) using the terms: severe maternal morbidity and maternal near miss, at each stage.For Silva JMP et al.
Severe maternal morbidity and near miss in Brazil: a systematic review MEDLINE, the strategy was: (near miss or severe morbidity) and maternal and Brazil.
The search was performed independently by JMPS (first author) and SCF (second author), and the disagreements were solved by consensus.An additional manual search in the bibliographic references of the articles included was carried out.
Initially the titles of the articles were evaluated and the titles rejected by both researchers were excluded.The titles approved by at least one of the authors went through a second stage, reading the abstracts.In this stage, the studies with abstracts approved by both authors were included.
From the selected abstracts, the full-text articles were read to confirm eligibility and to collect relevant information.For the reading and synthesis stages, besides the first and second authors, other authors have participated (academics in their last periods in Medicine, with interest in the area of Obstetrics).Each article was read by at least two authors (always the first or second author, plus a third one) independently, and the disagreements were solved by consensus.The reasons for the final exclusion are listed in the flowchart, as recommended by PRISMA. 7he data -author, location, population characteristics, guidelines, data source, severe maternal morbidity/near miss criteria and the main resultswere collected according to a pre-established spreadsheet.At least two of the authors read and analyzed all the articles.Among the results, the following quantitative indicators were highlighted: ratio or near miss incidence, MNM/MD and mortality rate.When the indicators were not described, but contained the necessary information for its calculation, it was estimated and added to the results in the review.
The methodological quality was not an inclusion/exclusion criterion in the analysis, considering that the purpose was to analyze a broad spectrum of studies on severe maternal morbidity, and to point out aspects referring to the methodology used.An experienced obstetrician on the subject also evaluated the summarization and the analysis of articles.
In order to organize the categories of the articles by prioritizing the data source, as proposed by Cecatti et al. 8 "studies on hospital population, studies on type of surveys and studies based on information systems".
This review is part of a study approved by the Ethics Committee of the Universitário Antônio Pedro on November 14, 2016, document number 1826053, to study the relation between near miss and neonatal outcomes.

Results
209 titles were identified in the MEDLINE search and 113 (considering the two combinations) in LILACS.After the exclusion of duplicates, selection and full reading of the articles, 48 studies for the systematic review were selected (Figure 1).
Tables 1 to 4 show that the studies are organized according to the data source type: hospital based (local and national), population surveys and information systems.Each category was preserved the chronological order of the publication, although there are some differences between this date and the moment of the implementation of the studies.
The 48 studies found were divided in: 37 hospital based; six were based on health surveys and five were based on information systems.The total number of the articles, 30 (62.5%) were published in international journals, all in English, 22 belonged in the Gynecology and Obstetrics and Reproductive Health areas.Among the 18 national publications, the most frequent journals were on Public Health (8), followed by Internal Medicine (7) and Gynecology-Obstetrics (3).Of the national internal medicine articles, four were exclusively published in English.

Local hospital based studies
In this category (Table 1), 22 studies were identified  originated from the Southeast (11) and Northeast (11) regions. Of tese, 12 were crosssectional studies, in which nine were only descriptive studies.The case-control type was a design of four studies and five of cohort studies, in which three were retrospective.One study was longitudinal, but just descriptive.
Most of the studies used the terminology "maternal near miss".Regarding to the criteria used for the definitions of near miss and severe maternal morbidity, 10 (44%) used the WHO criteria, 10 (40%) of Waterstone, 31 eight (32%) of Mantel, 32 three (16%) for the ICU admission, two (8%) the criteria proposed by Reichenheim et al., 4 two (8%) used life-threatening conditions as a criteria and only one used Geller's criteria. 33It is worth mentioning that most of the studies included more than one criterion in their analysis.Morse et al. 15 study compared three criteria, becaming the first one to use the WHO criteria in Brazilian studies.
Considering studies that adopted the WHO criteria, management and laboratorial criteria were the most prevalent, each being the most prevalent in two studies.Severe preeclampsia was the most common criterion identifier ever.

Table 1 continuation
Local hospital based studies.-Compared to the 9,318 other women, maternal near miss risk was higher in women who suffered abortion (PR=1.93;1.12-3.31).

continues
-The WHO management criteria were more common in insecure abortion cases.
-Factors associated to abortion complications: previous maternal conditions (sickle-cell anemia, low weight and neoplasia) and previous uterine scar Silva JMP et al.

Tabela 2 continuation
National hospital based studies / "Born in Brazil" study and "Multicenter study of the National Surveillance Network on Severe Maternal Morbidity".

Table 2 continuation
National hospital based studies / "Born in Brazil" study and "Multicenter study of the National Surveillance Network on Severe Maternal Morbidity".-WHO 3 Severe maternal morbidity and near miss in Brazil: a systematic review

continues
The MNMR varied from 4.4/1,000 LB, according to the WHO criteria, the 188.4/1,000LB, according to a criterion proposed by Reichenheim et al. 4 MNM: MD ratio was 3.3 cases/1 death to 8.6 cases/1 death, while the mortality rate was 10.6% to 23%.
The most frequent causes of MNM were the hypertensive disorders, such as severe pre-eclampsia and HELLP syndrome.The factors associated to maternal morbidity were: maternal age equal to or greater than 35 years, current or previous cesarean delivery, chronic hypertension, < 6 pre-natal consultations.
"Nascer no Brasil" (Born in Brazil") research was a hospital based study, covering all the Brazilian regions, but including only hospitals with more than 500 births per year and excluding cases of abortion and hospitalization during pregnancy, which did not apply to the main goal of the study. 5he sample had 243 maternal near miss cases with an estimated 23,747 occurrences of maternal near miss in the Country, resulting in an incidence of 10.2/1,000 live births. 5The incidence of maternal near miss was higher in women over 35 years of age, low schooling, previous cesarean history, complications during pregnancy, without prenatal care and with current cesarean section.Factors associated to statistical significance were: absence of prenatal care, obstetric complications, cesarean section and pilgrimage before the delivery. 34he multicenter study of the Rede Brasileira de Vigilância da Morbidade Materna Grave (Brazilian Surveillance Network on Severe Maternal Morbidity) evaluated twenty-seven hospitals distributed throughout all regions of Brazil 35 between 2009 and 2010.A prospective data collection used the WHO criteria for near miss and potentially lifethreatening conditions.This research methodology was similar to most articles (Table 2).
From 82,144 deliveries with live fetuses, 9,555 (11.6%) women were classified as having some kind of a severe outcome: 8,645 (90.5%) presented severe complications, 770 (8.1%) were classified as maternal near miss (WHO criteria) and 140 (1.5%) died. 35Several articles originated from this population data, although there were no comparative studies among these 9,555 women and those who had their childbirths in the 27 units, however presenting no complications.The aspects that differ from the methodology of the study are shown in Table 2, along with each of the 13 articles.Cecatti et al. 35 present overall results, and the other articles explore MNM according to age group 36 and with specific conditions: abortion, 37 ectopic pregnancy, 38 hypertensive diseases, 39,40 hemorrhage, 41,42 infections, 43,44 heart diseases. 45Healthcare factors were also analyzed, such as quality of care 46 and the association with cesarean section 47 based on Robson's Classification.
Hypertensive disease was the main cause of maternal near miss (45%) and maternal death (30%), followed by hemorrhage (40.5% of maternal near miss and 26% of maternal deaths).More than 75% of the maternal death cases observed, more than one near miss criterion defined by WHO was found.The highest maternal near miss ratio occurred in women aged 40-49 (31.4/1,000LB), followed by the age of 35-39 (17.5/1,000LB), and 35-49 years old (20.55/1,000LB), compared to adolescents with a ratio of 7.14/1,000 LB. 36
Four studies relied on the 1996 and 2006 national surveys (DHS), with home interviews of women with live births in the previous five years 48- 50 and women with history of abortion. 51Cecatti et al. 52 used data from a vaccination campaign survey for women in the Amazon and the Northeast regions, while Rosendo and Roncalli 53 conducted a home survey in Natal City in Rio Grande do Norte State.The MNMR varied from 21.2/1,000 LB to 41.1/1,000 LB.Among the criteria used for MNM, the most observed were eclampsia and blood transfusion, except in the study in Natal City, where ICU hospitalization was more frequent. 53Hemorrhage was the clinical complication most commonly reported by women.
Age ≥ 35 years old, low schooling and non-white skin color were the most frequent socioeconomic factors associated.Other cited factors were absence of prenatal and pilgrimage for childbirth.

Information systems based studies
Of the five studies 4), only one evaluated the national data. 54Regarding the criteria, three [54][55][56] used Waterstone and Mantel's criteria, [54][55][56] and two 57,58 used the WHO criteria with some adaptations.Women with a history of gestation, delivery and puerperium, women diagnosed with severe maternal morbidity, and women hospitalized for obstetric procedures were included.Pre-eclampsia was the most frequent indicator by Waterstone and Mantel's criteria.
The authors used both maternal near miss, ratios varied from 32.2 and 44.4/1,000 LB, as severe/ extremely severe maternal morbidity, and the ratios varied from 36.7/1,000 women in patients55 to 52.9/1,000 deliveries. 56Nakamura-Pereira et al. 58 evaluated the information quality of the Sistema de Informações Hospitalares do Sistema Único de Saúde (SIH-SUS) (Hospital Information System of the Public Health Service) for the study on severe maternal morbidity and estimated low sensitivity (18.5%) with high specificity (94.3%).
In this group of studies, the worse primary care assistance, as well as the history of stillbirth children and ages between 35-49 years old were the variables associated to the poverty markers outcome.

Discussion
This review identified 48 studies on severe maternal morbidity/maternal near miss in Brazil.Unlike other themes in women and childhood health, there was a high number of studies in the Northeast region was observed.
In 2005, the first Brazilian article was published using the term maternal near miss. 9][33] Hypertensive diseases and hemorrhages shared as the main causes, according to the criterion.Both conditions remain as the main causes associated to maternal morbidity.Three approaches were adopted by the studies as regard to the data sources: 8 hospital based predominance, with local or national primary or secondary data; the use of the information systems, Sistemas de Informações Hospitalares do Sistema Ùnico de Saúde, Sistemas de Informação sobre Mortalidade (SIH-SUS, SIM) (Hospital Information System of the Public Health Service, Information System on Mortality), and also the local or national population surveys.Each one showed advantages and fragilities.
In the case of hospital based studies, the main problem concern management criteria of the WHO classification.Depending on the infrastructure, the existence of protocols and the quality of the team, the indications and applications of some procedures can vary widely among institutions.The ICU indication, alone, is already considered as a near miss criterion and is very dependent on the factors above.
Limitations for the WHO near miss criteria in case of using the SIH-SUS as a data source: difficulty in correlating these criteria with diagnoses of ICD-10 and with procedures codes adopted by SIH-SUS 56 and low sensitivity. 59However, Magalhães et al. 57 used the SIH as a source and WHO criteria in their study, and evaluated the results found as satisfactory.Silva et al. 56 supports the use of Waterstone's criteria for studies with SIH to increase sensitivity.
In relation to the national surveys, such as DHS, the information is self-referred and there are no forms to prove the diagnoses.Souza et al. 49 comment on the limitations of the questionnaires used in this type of survey.When referring to their morbidities, women remember more of the interventions than the clinical complications; they rarely report eclampsia, for example.
The heterogeneity of the terminology was observed: Severe Maternal Morbidity, Extremely Severe Maternal Morbidity and Maternal Near Miss.In some cases, the authors use the terms indiscriminately and sometimes they use Severe Maternal Morbidity (SMM) as the synonym of Life Threatening Conditions.This heterogeneity implies the difficulty to compare results within the studies, but notice that the term maternal near miss prevailed.There was also heterogeneity in relation to the indicator that expresses the relative frequency of MNM.The MNM ratio was calculated when the denominator consisted on the number of live births and the incidence was calculated when the denominator referred to the number of childbirths or hospitalized women.
The study on maternal near miss showed the potential of indicators proposed by WHO as predic-Severe maternal morbidity and near miss in Brazil: a systematic review tors of maternal death: women that presented three or more criteria were more likely to die than those that presented only one criterion. 35here was also a similarity between the causes of MNM and those of maternal death in Brazil.Direct obstetric causes still prevail, but indirect ones are increasing.This pattern, allied to the increase of cesarean sections confirm that the presents itself in an obstetric transition movement. 59he most frequently associated factors in this study with MNM/SMM/ESMM were: age ≥ 35 years old, low schooling, current or previous cesarean section, hemorrhage, previous hypertension and prior abortion.
Inequalities inmaternal health were evidenced as regarding maternal morbidity.Considering the MNM/MD as an indicator to assess the quality of obstetric care after women's admission, the values observed were three times lower in regions with the lowest HDI in the Country 39 In Pfitscher et al., 43 study considering that the H1N1 pandemic and its effect maternal near miss, it was observed that non-white women progressed more frequently for more severe conditions, including death.Pacagnella et al. 46 analyzed any presence of delays in pregnant women care and showed that non-white color adolescence with low schooling were strongly associated.In relation to the age group, Oliveira Jr. et al. 36 found the lowest MNMR in women aged 10 to 19 years old, however this age group had the most delays in care.The inequities in relation to these variables add to of other maternal and child health outcomes, such as prenatal access. 60n the other hand, a protective effect was observed in relation to MNM for the beneficiary families of Bolsa Família Program 55 (a Government program for extreme low income family to receive like an allowance) and the protective association of prenatal care regarding MNM was well evidenced. 18,24,28,46It ratifies that complementing both politics and income as a basic care can reverse inequalities.However, it is necessary to improve prenatal care adequacy in SUS, considering that some studies showed worse performance compared to private prenatal care.
Brazil is known worldwide for the high incidence of cesarean sections. 61In several studies, previous or current cesarean section was associated to MNM/ESMM/SMM. 21,22,24,25,27,29,34,52 Only oe study showed cesarean section as a protective factor. 17The maternal near miss rate for cesarean section was 91 cases/1,000 deliveries whereas the incidence rate on vaginal delivery was 16 /1,000 deliveries. 32Although it is not possible to evidence a direct association, in virtue of an adequate procedure for several gestational risk situations, even though the cesarean section rate was high and the association to postpartum hemorrhage, identified in some studies, does not justify for the prior indication but could be attributed to the procedure.Adopting Robson's classification to monitor and compare cesarean indications should be a national recommendation.
As for abortion, about 2% of the women (more than 450) interviewed in the "Born in Brazil" research reported the tentative to interrupt their current gestation. 60Souza et al. 9 and Galvão et al. 22 studies found an association between previous abortion and maternal near miss, and Santana et al. 37 and Camargo et al. 51 studies reported a higher risk of near miss in women submitted to abortion.
An evaluation of national base studies is required."Born in Brazil" research was a hospital based study covering all the Brazilian regions, including only hospitals with more than 500 childbirths per year and excluding cases of abortion and hospitalization during pregnancy which was not the main goal of this study. 5As most births in Brazil occur in a hospital environment, this study could be considered as a population study approach, except for the above limitations.Their results, consistent with those studies at the local level have a great relevance for guiding health policies.
This study showed an association between cesarean section and maternal near miss, even after the adjustments on obstetric complications and two groups of women were identified: the first, white skin, high schooling, adequate prenatal care, no history of pilgrimage for delivery and a high frequency of elective cesarean section; and the second one, mixed or black skin, low schooling, younger, with absence of prenatal care and a higher frequency of vaginal delivery.Domingues et al. 34 concluded that indiscriminate use of cesarean section may approximate the occurrence of MNM between the two groups.However, if the interpretation of the hierarchical model was used, preserving distal factors without adjustment, there was a positive association between age ≥ 35 years old, low schooling, primiparity and previous cesarean section (considering the OR obtained in model 1, without adjusting for intermediate and distal variables).This analysis reinforces inequality in near miss occurrence and the importance of previous cesarean section.
Studies derived from the Multicenter Surveillance Network for Severe Maternal Morbidity explored for the first time MNM subgroups according to different conditions and increasing the knowledge on maternal morbidity.Maternity hospitals were select from five Brazilian regions, with a greater representation in the Southeast, mainly São Paulo State.As a limitation, the maternities included were predominantly tertiary/reference and were not representative of the morbidity population profile.This is confirmed by the MMR found in the study of 170/100,000 live births.However, they managed to capture in these locations a large number of patients with severe maternal morbidity, increasing statistical power of the results.
Another limitation was the absence of comparison with the control group (women without complications in the maternity hospitals), which does not allow to identify the population risk factors.In contrast, it was possible to evaluate the severity gradient in the subgroups in the same clinical condition, observing the relationship between PLTC, MNM and MD.The highest mortality rate was found for respiratory diseases (32.2%), with emphasis on H1N1 (51.8%), followed by infections (26.3%), heart diseases (24%), eclampsia (19%), postpartum hemorrhage (15%), hypertensive disease (10.7%), and antepartum hemorrhage (9%).Although the mortality rate for hemorrhagic conditions is not so high, the frequency of placental abruption is high, contributing for near miss.When the data was collected for this study, there was a H1N1 pandemic underway (2009) and the severity of this infection in pregnant women revealed high morbidity and mortality.
When comparing these two studies, a very similar MNM ratio was observed, but the MMR was much higher in the Multicenter Network study.In addition to the reasons explained above, "Born in Brazil" study did not directly estimate maternal deaths, but used a proxy, which may have contributed to the difference found.Regardless to the differences between the studies, several results are similar and corroborate the need to increase and qualify care for women.
There is a predominance of publications in international journals in the English language, which may hampered the dissemination of the near miss concept among health professionals in our Country.In international journals, the area of Reproductive Health was predominant, while in national journals, public health showed to be more productive and there were only three articles in the journals of the Gynecology-Obstetrics specialty.
As the limitations of this review, we point out the bibliographic search, which unpublished studies were not included.We only used well-known keywords used by WHO: near miss and severe maternal morbidity.However, we believe that we have made our search more specific, considering that many national studies have already incorporated the WHO terminology.We would like to suggest the incorporation of the terms to the health descriptors.
Regarding possible information bias, the reading and extraction of the data by more than one researcher, independently, contributed to its attenuation.
There are no other systematic national reviews on the subject, and the most recent review included a few Brazilian studies. 6And besides that, this study goes back to prior studies conducted before the WHO definition for near miss.Therefore, comparison is limited.Nevertheless, we highlight the heterogeneity of the near miss criteria, the prevalence of hospital based studies and the presence of social inequalities.
The study on maternal morbidity has been relevant in Brazil in pointing out fragile points in the health services.Although the results vary, the frequency of women with potential life-threatening complications is high in Brazil, which reinforces the need to universalize more complex interventions as well as coverage of primary care. 62e conclude that the evaluation of maternal near miss should be implanted as a routine in the maternity hospitals, using the WHO criteria of greater specificity and adding other criteria according to the capacity of each unit, in increasing sensitivity.It is important to emphasize that it should not only be an aid for the study on maternal mortality, but also for the conditions of maternal morbidity in pregnancy, childbirth and the puerperium.
In the research field, the theme is not exhausted; other studies evaluating more than one criterion and using longitudinal outlines are necessary to deepen the understanding of maternal morbidity and mortality in Brazil.

Figure 1 Flowchart 1 :
Figure 1Flowchart on the selection of articles.
).-MNMR= 9.37/1,000 LB; MDR= 170/100,000; MNM/ MD ratio= 5.5:1; Mortality rate= 15.4% -Hemorrhage was the most frequent for MNM and MD, in comparison to PLTC; the same occurred for infection.Hypertension was more prevalent in PLTC and declined as the outcome became more severe -The most frequent Near miss criteria was management (58.3%)followed by clinical (50.3%) and laboratorial (50%) -In the presence of only 1 criteria, the.probability of MD was small and in the presence of 3 criteria, it was high -Indirect causes represented 46% of the maternal deaths.National hospital based studies / "Born in Brazil" study and "Multicenter study of the National Surveillance Network on Severe Maternal Morbidity".PLTC (Potential life threatening conditions); SMO (Severe Maternal Outcome=MNM+MD); H1N1 (virus); HA (Hypertension); MD (maternal death); CI (confidence interval); SMM (severe maternal morbidity); MNM (Maternal Near Miss); LB (Live births); WHO (World Health Organization); OR (odds ratio); MMR (maternal mortality ratio); PR (Prevalence ratio); MNMR (Maternal Near Miss Ratio); HDI (Human Development Index).Pfitscher et al.,

Author and year of article Study location Type of study/ source/ analysis Studied Period Criteria Population Results Silva JMP et al. Table 1 continuation
LB= live births; WHO= World Health Organization; OR= odds ratio; MMR= maternal mortality ratio; SMMR= severe maternal morbidity ratio; PR= prevalence ratio; RR= relative risk; SUS= Public Health System; ICU= intensive care unit.

2018 15 Severe maternal morbidity and near miss in Brazil: a systematic reviewTable 1 continuation
Local hospital based studies.

Severe maternal morbidity and near miss in Brazil: a systematic reviewTable 1 continuation
Local hospital based studies.

Table 1 conluded
Local hospital based studies.

Table 2
National hospital based studies / "Born in Brazil" study and "Multicenter study of the National Surveillance Network on Severe Maternal Morbidity".

21 Severe maternal morbidity and near miss in Brazil: a systematic review
-Maternal near miss ratio for age groups and adjusted PR (95%CI) to SMO (MNM+MD), considering 20-34 years as reference: -40-49 years

Table 2 continuation
National hospital based studies / "Born in Brazil" study and "Multicenter study of the National Surveillance Network on Severe Maternal Morbidity".

Table 2 continuation
National hospital based studies / "Born in Brazil" study and "Multicenter study of the National Surveillance Network on Severe Maternal Morbidity".

Table 3
Population survey based studies.continues DHS= demographic and health survey; MD= maternal death; SMM= severe maternal morbidity; MNM= maternal near miss; LB= live births; OR= odds ratio; RN= Rio Grande do Norte; PR= prevalence ratio; ICU= intensive care unit.

Table 3 concluded
Population survey based studies.DHS= demographic and health survey; MD= maternal death; SMM= severe maternal morbidity; MNM= maternal near miss; LB= live births; OR= odds ratio; RN= Rio Grande do Norte; PR= prevalence ratio; ICU= intensive care unit.

Table 4
Information systems based studies on SIH-SUS and SIM.LB= live births; WHO= World Health Organization; PN= prenatal; HYPDR= MNM ratio for hypertensives diseases; HR= MNM ratio for hemorrhage; MNMR= maternal near miss ratio; PR= prevalence ratio; RR= relative risk; SIH= hospital information system; SIM= mortality information system; SUS= Public Health System; ICU= intensive care unit.

Table 4 concluded
Information systems based studies on SIH-SUS and SIM.PHC= primary healthcare; FHS= family health strategy; HELLP= hemolysis elevated liver enzymes low platelet; MD= maternal death; SMM= severe maternal morbidity; ESMM= extremely severe maternal morbidity; MNM= maternal near miss; LB= live births; WHO= World Health Organization; PN= prenatal; HYPDR= MNM ratio for hypertensives diseases; HR= MNM ratio for hemorrhage; MNMR= maternal near miss ratio; PR= prevalence ratio; RR= relative risk; SIH= hospital information system; SIM= mortality information system; SUS= Public Health System; ICU= intensive care unit.