Brazilian multicenter study on prevalence of preterm birth and associated factors

The relationship between active/passive smoking and spontaneous preterm birth: Data from a multicenter study

BACKGROUND

Prematurity is considered to be the leading cause of death in children under 5 years of age, with one child dying every 2 s. Smoking is known to be one of the factors associated with prematurity, with both immediate and late consequences. However, it is difficult to obtain concrete data on the relationship between smoking and spontaneous preterm birth.

OBJECTIVE

The aim of this study was to evaluate the influence of active and passive smoking on spontaneous preterm birth.

METHODS

This was a multicenter, cross-sectional complementary study that included data on preterm births in 20 maternity hospitals in Brazil between 2011 and 2012. The relationship between smoking category (people who smoke [PWS]; people who smoke indirectly [PWSI]; and people who do not smoke [PWDNS]) and sociodemographic characteristics, birth, and neonatal data was assessed. Statistical analysis was performed using frequencies, percentages, the χ2 test, and stepwise comparisons, with a significance level of 5%.

RESULTS

The original study included 5295 pregnant participants and their preterm infants. There were 1491 spontaneous preterm births (SPBs); 1191 preterm rupture of membranes; 1468 therapeutic preterm births; and 1146 term births. The proportion of women who were PWS during pregnancy was 13.5%, and 31.6% were PWSI. Pregnant individuals who smoked and who smoked indirectly had a higher incidence of SPBs (61.2%) compared with PWDNS (48.4%; P < 0.0001); however, multivariate analysis did not confirm causality.

CONCLUSIONS

This study did not confirm that smoking during pregnancy increases the risk of SPB. PWSI also did not have an increased incidence of spontaneous preterm birth or adverse neonatal outcomes.

Diabetes among women with preterm births: outcomes of a Brazilian multicenter study

OBJECTIVE

The objective was to compare the maternal and perinatal characteristics and outcomes between women with and without diabetes in a Brazilian cohort of women with preterm births.

METHODS

This was an ancillary analysis of the Brazilian Multicenter Study on Preterm Birth, which included 4,150 preterm births. This analysis divided preterm births into two groups according to the presence of diabetes; pregestational and gestational diabetes were clustered in the same Diabetes Group. Differences between both groups were assessed using χ 2 or Student's t tests.

RESULTS

Preterm births of 133 and 4,017 women with and without diabetes, respectively, were included. The prevalence of diabetes was 3.2%. Pregnant women aged ≥35 years were more common in the Diabetes Group (31.6% versus 14.0% non-diabetic women, respectively). The rate of cesarean section among patients with diabetes was 68.2% versus 52.3% in non-diabetic cases), with a gestational age at birth between 34 and 36 weeks in 78.9% of the cases and 62.1% of the controls. Large-for-gestational-age babies were 7 times more common in the Diabetes Group.

CONCLUSION

Preterm birth among Brazilian women with diabetes was more than twice as prevalent; these women were older and had regular late preterm deliveries, usually by cesarean section. They also had a greater frequency of fetal morbidities, such as malformations and polyhydramnios, and a higher proportion of large-for-gestational-age and macrosomic neonates.

Prediction and prevention of preeclampsia by physicians in Brazil: An original study

BACKGROUND

Considering the worldwide importance of preeclampsia, especially in Brazil, the screening of pregnant women at greater risk of developing the disease and the application of preventive measures are essential. This study aimed to assess the medical performance in this context in Brazil.

METHODS

A survey was developed to quantify the number of physicians who prescribe acetylsalicylic acid (ASA) and/or calcium for preeclampsia prevention. The survey was sent to all Brazilian obstetricians affiliated to the Brazilian Federation of OBGYN by email and WhatsApp. The survey remained opened for 6 months and included questions about the use of ASA and calcium, as well as about the use of a complementary test to predict preeclampsia.

RESULTS

The sample consisted of 360 responding physicians and 100% coverage of responses from physicians from the five different regions of Brazil was obtained. The vast majority of respondents (94.72%) prescribe ASA to prevent preeclampsia, with 80.3% prescribing a dose of 100 mg/day. Calcium is prescribed by 83.9% of the respondents. The majority of the interviewed sample (58.6%) requests uterine artery Doppler imaging to predict preeclampsia and 31.7% do not request any additional test. When the analysis was performed by region, only the northern region differed from the other Brazilian regions regarding the use of ASA and calcium for preeclampsia prevention. While more than 90% of physicians in the other regions prescribe ASA, 40% in the northern region do not use it (p < 0.0001). Regarding calcium, 30% of physicians in northern Brazil do not use the drug for preeclampsia prevention, a percentage that also differs from the other regions where the medication is prescribed by 80 to 90% of physicians (p = 0.021).

CONCLUSIONS

The vast majority of Brazilian physicians prescribe low-dose aspirin and calcium carbonate to prevent preeclampsia in high-risk pregnant women. In addition to the identification of clinical risk factors, most doctors use Doppler of the uterine arteries as a predictive method. In the northern region of Brazil, physicians use aspirin and calcium less frequently for preventing preeclampsia compared to the rest of the country.

Pre-eclampsia: Universal Screening or Universal Prevention for Low and Middle-Income Settings?

Pre-eclampsia (PE) is a severe disorder that affects up to 8% of all pregnancies and represents an important cause of maternal and perinatal morbidity and mortality. The screening of the disease is a subject of studies, but the complexity and uncertainties regarding its etiology make this objective a difficult task. In addition, the costs related to screening protocols, the heterogeneity of the most affected populations and the lack of highly effective prevention methods reduce the potential of current available algorithms for screening. Thus, the National Specialized Commission of Hypertension in Pregnancy of the Brazilian Association of Gynecology and Obstetrics Federation (Febrasgo, in the Portuguese acronym) (NSC Hypertension in Pregnancy of the Febrasgo) considers that there are no screening algorithms to be implemented in the country to date and advocates that Aspirin and calcium should be widely used.

Prevalence, Etiology, and Associated Symptoms of Vaginal Discharge During Pregnancy in Women Seen in a Tertiary Care Hospital in Bihar

Introduction

Vaginal discharge is the most frequent complaint during pregnancy, leading to numerous complications in both the mother and fetus.

Aim

The goal of this study was to determine the prevalence of vaginal discharge, investigate its common infectious causes and associated symptoms during pregnancy.

Methods

This hospital-based cross-sectional study performed over one year evaluated 200 expectant mothers with vaginal discharge at any trimester in the Department of Obstetrics and Gynecology, in cooperation with the Microbiology section, of Indira Gandhi Institute of Medical Science, Patna.

Results

The mean age of the mothers was 26.84±5.51 years (range 19-42 years). Most of the patients (47.5%) were in the age group of 26-35 years, belonged to the lower socioeconomic class (67.5%), gravida 3 or more (43.5%), and presented in the third trimester. The prevalence of pathological discharge in pregnancy was 148/308 (48.05%). A positive culture was obtained in 105 (52.5%), and negative culture was obtained in 95 (47.5%). Vaginal candidiasis was diagnosed in most cases (37.5%), followed by aerobic vaginitis (15%), trichomoniasis (13.0%), and bacterial vaginosis (8.5%). The non-pathological discharge was diagnosed in 26.0%. Dysuria was the most common symptom (32.5%), followed by itching (27.5%) and urinary tract infection (UTI; 10.0%). The following variables were significantly associated (P<0.05) with discharge: age (in years), age group, gravida, culture, organism isolated on culture, UTI as a symptom, and diagnosis.

Conclusion

Expectant mothers presenting with vaginal discharge need to be evaluated to identify the etiology and allow timely treatment, which might be helpful in preventing complications.

The role of maternal infection in preterm birth: evidence from the Brazilian Multicentre Study on Preterm Birth (EMIP)

OBJECTIVES

Evidence suggests that infection or inflammation is a major contributor to early spontaneous preterm birth (sPTB). Therefore, this study aimed to investigate the development and causes of maternal infection associated with maternal and neonatal outcomes in women with sPTB.

METHODS

This was a secondary analysis of a multicenter cross-sectional study with a nested case-control component, the Brazilian Multicentre Study on Preterm Birth (EMIP), conducted from April 2011 to July 2012 in 20 Brazilian referral obstetric hospitals. Women with preterm birth (PTB) and their neonates were enrolled. In this analysis, 2,682 women undergoing spontaneous preterm labor and premature pre-labor rupture of membranes were included. Two groups were identified based on self-reports or prenatal or hospital records: women with at least one infection factor and women without any maternal infection (vulvovaginitis, urinary tract infection, or dental infection). A bivariate analysis was performed to identify potential individual risk factors for PTB. The odds ratios (ORs) with their respective 95% confidence intervals were calculated.

RESULTS

The majority of women with sPTB fulfilled at least one criterion for the identification of maternal infection (65.9%), and more than half reported having urinary tract infection during pregnancy. Approximately 9.6% of women with PTB and maternal infection were classified as having periodontal infection only. Apart from the presence of a partner, which was more common among women with infectious diseases (p=0.026; OR, 1.28 [1.03-1.59]), other variables did not show any significant difference between groups.

CONCLUSION

Maternal infection was highly prevalent in all cases of sPTBs, although it was not clearly associated with the type of PTB, gestational age, or any adverse neonatal outcomes.

Hypertension and maternal urinary tract infection and the metabolic conditions of preterm infants

OBJECTIVE

The present study evaluated the anthropometric and metabolic profiles of preterm infants (PT) born from mothers with urinary tract infections (UTI) and mothers with hypertensive disorders (HD).

METHOD

This was a longitudinal prospective study conducted between May 2015 and August 2016. First, 59 mothers with premature birth were included; after excluding 29 mothers, two subgroups were created: UTI-mothers (n=12) and HD-mothers (n=18). The anthropometric and metabolic variables of mothers and their respective PT were analyzed at birth and at 6 months of corrected age (CA).

RESULTS

Plasma triglyceride levels were higher among HD-mothers and their respective PT in comparison with UTI-mothers and their PT at 6 m of CA.

CONCLUSION

Plasma triglyceride level is an important metabolic biomarker in HD-mothers resulting in higher triglyceride levels among PT at the CA of 6 m, suggesting an early programming effect of maternal hypertension.

Association Between Prematurity and Diagnosis of Neurodevelopment Disorder: A Case-Control Study

The aim of this study is to investigate the association between prematurity and diagnosis of neurodevelopmental disorders (ND) (attention deficit/hyperactivity disorder [ADHD] or autism spectrum disorder [ASD]) in Brazilian children and adolescents. Case-control study based on medical records data from a specialized outpatient clinic. Prematurity was defined as gestational age less than 37 weeks. Prematurity was independently associated with diagnosis of a ND (adjusted odds ratio [AOR] 3.46, 95% CI 1.15 - 7.92), as well as with ADHD and ASD diagnosis after a multiple logistic regression analysis. These findings from Brazilian patients are related to what is found in the literature worldwide. Efforts to modify risk factors, such as prematurity, may impact incidence reduction of both ADHD and ASD.

Cluster analysis identifying clinical phenotypes of preterm birth and related maternal and neonatal outcomes from the Brazilian Multicentre Study on Preterm Birth

OBJECTIVE

To explore a conceptual framework of clinical conditions associated with preterm birth (PTB) by cluster analysis, assessing determinants for different PTB subtypes and related maternal and neonatal outcomes.

METHODS

Secondary analysis of the Brazilian Multicentre Study on Preterm Birth of 33 740 births in 20 maternity hospitals between April 2011 and July 2012. In accordance with a prototype concept based on maternal, fetal, and placental conditions, an adapted k-means model and fuzzy algorithm were used to identify clusters using predefined conditions. The mains outcomes were phenotype clusters and maternal and neonatal outcomes.

RESULTS

Among 4150 PTBs, three clusters of PTB phenotypes were identified: women who had PTB without any predefined conditions; women with mixed conditions; and women who had pre-eclampsia, eclampsia, HELLP syndrome and fetal growth restriction. The prevalence of different preterm subtypes differed significantly in the three clusters, varying from 80.95% of provider-initiated PTBs in cluster 3-6.62% in cluster 1 (P<0.001). Although some maternal characteristics differed among the clusters, maternal and neonatal outcomes did not.

CONCLUSIONS

The analysis identified three clusters with distinct phenotypes. Women from the different clusters had different subtypes of PTB and maternal and pregnancy characteristics.

Twin Pregnancy in Brazil: A Profile Analysis Exploring Population Information from the National Birth E-Registry on Live Births

Birth records as SINASC (Brazilian Live Birth Information System) are highlighted in uncommon conditions such as twin pregnancy whose prevalence rarely exceeds 2 to 3% of the total number of births. The objective of this study was to assess the prevalence of twin pregnancies in Brazil and their maternal and perinatal characteristics using data from the national birth e-Registry. All births in Brazil from 2011 to 2014 were assessed. Prevalence of twin pregnancies per region was assessed and correlated with the Human Development Index (HDI). Sociodemographic and obstetric factors and main perinatal outcomes were assessed for the first and second twin, in comparison to singletons, and the second twin compared to the first twin, with PR and 95%CI. A multiple logistic regression analysis was conducted to identify factors independently associated with a low 5-minute Apgar score in twin pregnancies. Twin pregnancy occurred in 1.13% in Brazil, with a higher prevalence in regions with a higher HDI. It was associated with a complete higher level of education (22.9% versus 16.3% for singles) and maternal age > 35 years (17.5% versus 11.4% for singles). Preterm birth <32 weeks (prevalence ratio-PR 12.13 [11.93 – 12.33]), low birth weight (PR 17.8 [17.6-18.0] for the first and PR 20.1 [19.8-20.3] for the second twin), and low Apgar score (PR 2.9 [2.8-3.0] for the first and PR 2.7 [2.6-2.8] for the second twin) were the most important perinatal outcomes associated with twin pregnancies. A 5-minute Apgar score < 7 among twins was associated with inadequate prenatal care, extreme preterm birth, vaginal delivery, intrapartum cesarean, and combined delivery. Twin pregnancy in Brazil is associated with worse perinatal outcomes, especially for the second twin.

Risk factors for premature birth in French Guiana: the importance of reducing health inequalities

OBJECTIVES

French Guiana has the highest birth rate in South America. This French territory also has the highest premature birth rate and perinatal mortality rate of all French territories. The objective was to determine the premature birth rate and to identify the prevalence of risk factors of premature birth in French Guiana.

METHODS

A retrospective study of all births in French Guiana was conducted between January 2013 and December 2014 using the computerized registry compiling all live births over 22 weeks of gestation on the territory.

RESULTS

During this period 12 983 live births were reported on the territory. 13.5% of newborns were born before 37 (1755/12 983). The study of the registry revealed that common sociodemographic risk factors of prematurity were present. In addition, past obstetrical history was also important: a scarred uterus increased the risk of prematurity adjusted odds ratio =1.4, 95%CI (1.2-1.6). Similarly, obstetrical surveillance, the absence of preparation for birth or of prenatal interview increased the risk of prematurity by 2.4 and 2.3, the excess fraction in the population was 69% and 72.2%, respectively.

CONCLUSIONS

Known classical risk factors are important. In the present study excess fractions were calculated in order to prioritize interventions to reduce the prematurity rate.

EXPERIENCE WITH THE BRAZILIAN NETWORK FOR STUDIES IN REPRODUCTIVE AND PERINATAL HEALTH: THE POWER OF COLLABORATION IN POSTGRADUATE PROGRAMS

The scientific collaboration in networks may be developed among countries, academic institutions and among peer researchers. Once established, they contribute for knowledge dissemination and a strong structure for research in health. Several advantages are attributed to working in networks: the inclusion of a higher number of subjects in the studies; generation of stronger evidence with a higher representativeness of the population (secondary generalization and external validity); higher likelihood of articles derived from these studies to be accepted in high impact journals with a wide coverage; a higher likelihood of obtaining budgets for sponsorship; easier data collection on rare conditions; inclusions of subjects from different ethnic groups and cultures, among others. In Brazil, the Brazilian Network for Studies on Reproductive and Perinatal Health was created in 2008 with the initial purpose of developing a national network of scientific cooperation for the surveillance of severe maternal morbidity. Since the establishment of this Network, five studies were developed, some of them already finished and others almost being completed, and two new ones being implemented. Results of the activities in this Network have been very productive and with a positive impact on not only the Postgraduate Program of Obstetrics and Gynecology from the University of Campinas, its coordinating center, but also on other participating centers. A considerable number of scientific articles was published, master´s dissertations and PhD theses were presented, and post-doctorate programs were performed, including students from several areas of health, from distinct regions and from several institutions of the whole country. This represents a high social impact taking into account the relevance of the studied topics for the country. As colaborações científicas em rede podem ocorrer entre países, instituições acadêmicas e entre pares de pesquisadores e, uma vez estabelecidas, contribuem para a disseminação do conhecimento e estruturação da pesquisa em saúde. Diversas vantagens são atribuídas ao trabalho em rede como: a inclusão de maior número de participantes nos estudos; gerar evidências mais fortes e com maior representatividade da população (generalização secundária e validade externa); maior facilidade das publicações oriundas dos estudos serem aceitas em periódicos de impacto e abrangência; maior probabilidade de obtenção de verbas para financiamento; maior facilidade na coleta de dados sobre condições raras; inclusão de participantes de diferentes grupos étnicos e culturas, entre outras. No Brasil a Rede Brasileira de Estudos em Saúde Reprodutiva e Perinatal foi criada em 2008 com o objetivo inicial de desenvolver rede nacional de cooperação científica para vigilância da morbidade materna grave. Desde sua formação, cinco estudos foram desenvolvidos, alguns já encerrados e outros em fase de finalização, com outros dois em fase final de implantação. Os resultados das atividades desta Rede têm sido bastante produtivos e impactaram positivamente não apenas no Programa de Pós-Graduação em Tocoginecologia da Universidade Estadual de Campinas, seu centro coordenador, mas também o de outros centros participantes, uma vez que expressivo número de artigos científicos foi publicado, mestrados e doutorados foram defendidos e pós-doutorados finalizados, de alunos de diversas áreas da saúde, de diferentes regiões e de várias instituições de todo o país, com alto impacto social dada a relevância dos temas estudados para o país.

The Burden of Provider-Initiated Preterm Birth and Associated Factors: Evidence from the Brazilian Multicenter Study on Preterm Birth (EMIP)

Background

About 15 million children are born under 37 weeks of gestation worldwide. Prematurity is the leading cause of neonatal deaths and short/long term morbidities, entailing consequences not only for the individual, but also their family, health agencies, facilities and all community. The provider-initiated preterm birth is currently one of the most important obstetric conditions related to preterm births, particularly in middle and high income countries, thus decreasing the need for therapeutic preterm birth is essential to reduce global prematurity. Therefore detailed knowledge on the factors associated with provider-initiated preterm birth is essential for the efforts to reduce preterm birth rates and its consequences. In this current analysis we aimed to assess the proportion of provider-initiated (pi-PTB) among preterm births in Brazil and identify associated factors.

Methods and Findings

This is an analysis of a multicenter cross-sectional study with a nested case-control component called Brazilian Multicenter Study on Preterm Birth (EMIP). EMIP was conducted in 20 referral obstetric hospitals located in the three most populated of the five Brazilian regions. We analysed data of women with pi-PTB, defined as childbirth occurring at less than 37 weeks, medically indicated for maternal/fetal compromise or both; and women with term birth, childbirth at or after 37 weeks. Maternal, sociodemographic, obstetric, prenatal care, delivery, and postnatal characteristics were assessed as possible factors associated with pi-PTB, compared to term births. The overall prevalence of preterm births was 12.3%. Of these, approximately one-third of cases were initiated by the provider. Hypertensive disorders, placental abruption, and diabetes were the main maternal conditions leading to pi-PTB. Caesarean section was the most common mode of delivery. Chronic hypertension (OR 7.47; 95%CI 4.02–13.88), preeclampsia/eclampsia/HELLP syndrome (OR 15.35; 6.57–35.88), multiple pregnancy (OR 12.49; 4.86–32.05), and chronic diabetes (OR 5.24; 2.68–10.25) were the most significant factors independently associated with pi-PTB.

Conclusions

pi-PTB is responsible for about one-third of all preterm births, requiring special attention. The decision-making process relative to the choice of provider-initiated birth is complex, and many factors should be elucidated to improve strategies for its prevention, including evidence-based guidelines on proper management of the corresponding clinical conditions.

Network for Surveillance of Severe Maternal Morbidity: a powerful national collaboration generating data on maternal health outcomes and care

OBJECTIVE

To identify cases of severe maternal morbidity (SMM) during pregnancy and childbirth, their characteristics, and to test the feasibility of scaling up World Health Organization criteria for identifying women at risk of a worse outcome.

DESIGN

Multicentre cross-sectional study.

SETTING

Twenty-seven referral maternity hospitals from all regions of Brazil.

POPULATION

Cases of SMM identified among 82 388 delivering women over a 1-year period.

METHODS

Prospective surveillance using the World Health Organization's criteria for potentially life-threatening conditions (PLTC) and maternal near-miss (MNM) identified and assessed cases with severe morbidity or death.

MAIN OUTCOME MEASURES

Indicators of maternal morbidity and mortality; sociodemographic, clinical and obstetric characteristics; gestational and perinatal outcomes; main causes of morbidity and delays in care.

RESULTS

Among 9555 cases of SMM, there were 140 deaths and 770 cases of MNM. The main determining cause of maternal complication was hypertensive disease. Criteria for MNM conditions were more frequent as the severity of the outcome increased, all combined in over 75% of maternal deaths.

CONCLUSIONS

This study identified around 9.5% of MNM or death among all cases developing any severe maternal complication. Multicentre studies on surveillance of SMM, with organised collaboration and adequate study protocols can be successfully implemented, even in low-income and middle-income settings, generating important information on maternal health and care to be used to implement appropriate health policies and interventions.

TWEETABLE ABSTRACT

Surveillance of severe maternal morbidity was proved to be possible in a hospital network in Brazil.

Methodological issues on planning and running the Brazilian Multicenter Study on Preterm Birth

OBJECTIVES

Assuming that the occurrence of preterm births and their maternal and neonatal associated conditions in Brazil are not completely known, a multicenter study was proposed. The purpose of this paper is to describe the methods used, its processes, achievements, and challenges.

STUDY DESIGN

A multicenter cross-sectional study on preterm births in Brazilian facilities plus a nested case-control study to assess their associated factors. A description of all steps of planning and implementing such a nationwide study, including strategies for dealing with problems arising during the process, is presented.

RESULTS

20 referral hospitals in different regions of Brazil participated in the study. A detailed questionnaire for data collection, an electronic platform for data transcription and monitoring, research materials, and specific monitoring tools were developed; then data management and analyses were performed. Finally, we got information on 4,150 preterm births and 1,146 term births.

CONCLUSIONS

This study represented the first step of a planned comprehensive assessment of preterm birth in Brazil, with detailed information that will lead to several analyses and further studies, bringing the knowledge to improve screening, diagnosis, and treatment practices in maternal and perinatal health with the final purpose of reducing the burden of this condition in the country.

Brazilian multicentre study on preterm birth (EMIP): prevalence and factors associated with spontaneous preterm birth

BACKGROUND

Preterm birth rate is increasing and is currently a worldwide concern. The purpose of this study was to estimate the prevalence of preterm birth in a sample of health facilities in Brazil and to identify the main risk factors associated with spontaneous preterm births.

METHODS AND FINDINGS

This was a multicentre cross sectional study on preterm births in 20 referral obstetric hospitals with a case-control component to identify factors associated with spontaneous preterm birth. Surveillance was implemented at all centres to identify preterm births. For eligible consenting women, data were collected through a post-delivery questionnaire completed with information from all mother-newborn medical records until death or discharge or at a maximum of 60 days post-delivery, whichever came first. The risk of spontaneous preterm birth was estimated with OR and 95%CI for several predictors. A non-conditional logistic regression analysis was then performed to identify independently associated factors. The overall prevalence of preterm birth was 12.3%. Among them, 64.6% were spontaneous and 35.4% therapeutic. In the case-control component, 2,682 spontaneous preterm births were compared to a sample of 1,146 term births. Multivariate analyses identified the following as risk factors for spontaneous preterm birth among women with at least one previous birth: a previous preterm birth (ORadj = 3.19, 2.30-4.43), multiple pregnancy (ORadj = 29.06, 8.43-100.2), cervical insufficiency (ORadj = 2.93, 1.07-8.05), foetal malformation (ORadj = 2.63, 1.43-4.85), polyhydramnios (ORadj = 2.30, 1.17-4.54), vaginal bleeding (ORadj = 2.16, 1.50-3.11), and previous abortion (ORadj = 1.39, 1.08-1.78). High BMI (ORadj = 0.94, 0.91-0.97) and weight gain during gestation (ORadj = 0.92, 0.89-0.95) were found to be protective factors.

CONCLUSIONS

The preterm birth rate in these health facilities in Brazil is high and spontaneous preterm births account for two thirds of them. A better understanding of the factors associated with spontaneous preterm birth is of utmost importance for planning effective measures to reduce the burden of its increasing rates.

Estimation of preterm birth rate, associated factors and maternal morbidity from a demographic and health survey in Brazil

To determine the prevalence of preterm birth from self-reports by Brazilian women, to assess complications, interventions and outcomes, to identify factors associated with preterm birth, and to improve the preterm birth rates estimates. This is a secondary analysis of data from a Demographic Health Survey. It interviewed a sample of 4,743 Brazilian women who had 6,113 live births from 2001 to 2007. Estimates of preterm birth rates were obtained per region and per year according to self-reported gestational age. The prevalence rate and 95 % confidence interval (CI) for preterm was determined according to the characteristics of mothers and offspring. Odds ratios and 95 % CI were estimated for complications such as severe maternal morbidity. The preterm birth rate was 9.9 %, with regional variations. Preterm birth was more likely to be associated with neonatal death, low birth weight, and longer hospital stay. Maternal factors associated with preterm birth were: white ethnicity, living in an urban area, history of hypertension or heart disease, twin gestation, non-elective Cesarean section, medical insurance for delivery, low number of antenatal visits, and severe morbidity. A self-report survey has indicated that the preterm birth rate in Brazil is higher than official data suggest, with an increasing trend in more developed areas, and is associated with poor neonatal and maternal outcomes.

Intracluster correlation coefficients for the Brazilian Multicenter Study on Preterm Birth (EMIP): methodological and practical implications

BACKGROUND

Cluster-based studies in health research are increasing. An important characteristic of such studies is the presence of intracluster correlation, typically quantified by the intracluster correlation coefficient (ICC), that indicate the proportion of data variability that is explained by the way of clustering. The purpose of this manuscript was to evaluate ICC of variables studied in the Brazilian Multicenter Study on Preterm Birth.

METHODS

This was a multicenter cross-sectional study on preterm births involving 20 referral hospitals in different regions of Brazil plus a nested case-control study to assess associated factors with spontaneous preterm births. Estimated prevalence rates or means, ICC with 95% confidence intervals, design effects and mean cluster sizes were presented for more than 250 maternal and newborn variables.

RESULTS

Overall, 5296 cases were included in the study (4,150 preterm births and 1,146 term births). ICC ranged from <0.001 to 0.965, with a median of 0.028. For descriptive characteristics (socio-demographic, obstetric history and perinatal outcomes) the median ICC was 0.014, for newborn outcomes the median ICC was 0.041 and for process variables (clinical management and delivery), it was 0.102. ICC was <0.1 in 78.4% of the variables and <0.3 for approximately 95% of them. Most of ICC >0.3 was found in some clinical management aspects well defined in literature such as use of corticosteroids, indicating there was homogeneity in clusters for these variables.

CONCLUSIONS

Clusters selected for Brazilian Multicenter Study on Preterm Birth had mainly heterogeneous findings and these results can help researchers estimate the required sample size for future studies on maternal and perinatal health.

Prevalence and risk factors associated with preterm birth in Ardabil, Iran

BACKGROUND

Preterm birth is a leading cause of perinatal mortality and long-term morbidity as well as the long-term health consequences and cognitive outcomes.

OBJECTIVE

Present study was conducted to determine prevalence and risk factors associated with preterm birth in Ardabil, Iran.

MATERIALS AND METHODS

A case control study was conducted between Nov 2010 and July 2011 in all three maternal hospitals in Ardabil. All the live newborns during the study period were investigated. Of 6705 live births during the study period 346 births occurred in <37 weeks were taken as a case and 589 term neonates were taken as a control group. Data were obtained through review of prenatal and hospital delivery records. Univariate and multivariate logistic regression analysis were applied to obtain magnitude of association between independent variables and preterm birth.

RESULTS

The prevalence rate of preterm birth was 5.1%. History of previous preterm birth (OR=12.7,CI: 3.9-40.4, p<0.001), hypertension (OR=7.3, CI:2.1-25.4, p=0.002), Oligohydramnios (OR=3.9, CI:1.6-9.5, p=0.002), spouse abuse (OR=3.7, CI:1.1-11.8, p=0.024), preeclampsia (OR=3.6, CI:1.3-10.3, p=0.014), premature rupture of membrane (OR=3.1, CI:1.9-4.9, p=0.000), bleeding or spotting during pregnancy (OR=2.0, CI:1.0-3.8, p=0.037), Hyperemesis Gravid arum (OR=2.0, CI: 1.1-3.8, p=0.015), urinary tract infection in 26-30 weeks , (OR=1. 8 CI:1.0-3.2, p=0.04), diastolic blood pressure ≤60 mmg (OR=1.5, CI: 0.99-2.2, p=0.049) were determined as significant risk factors for preterm birth.

CONCLUSION

Early detection and treatment of diseases or disorders among pregnant women especially hypertension, Oligohydramnios, preeclampsia, bleeding or spotting, Hyperemesis Gravid arum, urinary tract infection, and low diastolic blood pressure as well as the improving health care quality delivered to pregnant women may reduce preterm prevalence rate.

Pathological Vaginal Discharge among Pregnant Women: Pattern of Occurrence and Association in a Population-Based Survey

This study aimed to assess the prevalence of pathological vaginal discharge and to describe risk factors associated with pregnant women. All women living in the city of Rio Grande, Southern Brazil, who gave birth in 2010 were included in the study. A standardized questionnaire was administered to collect information on demographic, reproductive, and health-related factors and morbidity during pregnancy. The chi-square test was used to compare proportions, and multivariate Poisson regression with robust variance was performed. Of the 2,395 women studied, 43% had pathological vaginal discharge during pregnancy. The adjusted analysis showed that younger women of lower socioeconomic condition, those with a past history of abortion, vaginal discharge in a previous pregnancy, and treated for depression, anemia, and urinary tract infection during their current pregnancy, were more likely to have pathological vaginal discharge. Vaginal discharge during pregnancy was highly prevalent in the sample studied calling for proper risk factor management at the primary care level.

Maternal risk factors for low birth weight for term births in a developed region in China: a hospital-based study of 55,633 pregnancies

Low birth weight (LBW) is an important risk factor for neonatal and infant mortality and morbidity in adults.. However, no large scale study on the prevalence of LBW and related maternal risk factors in China has been published. To explore the effects of maternal factors on LBW for term birth in China, we conducted a hospital-based retrospective study of 55, 633 Chinese pregnancy cases between 2001 and 2008. Maternal sociodemographic data, history of infertility and contraceptive use were obtained. Their medical status and diseases during pre-pregnancy were examined by physical examination at the first antenatal care visit. Maternal medical status before childbirth and pregnancy outcomes, including body weight, infant gender, multiple pregnancy and congenital anomalies, were recorded. Univariate and multivariate logistic regression, and linear regression were used to investigate the relationship between maternal factors and term LBW. The general incidence of term LBW was 1.70% in the developed area of China. After preliminary analysis using the univariate model, low primary education, anemia, hypertensive disorders, placental previa, oligohydramnios and premature rupture of membrane were predicted as independent factors of term LBW in the multivariate model. Furthermore, the decrease in annual frquencies of these risk factors were major causes of gradual decline in the incidence of LBW (from 2.43% in 2001 to 1.21% in 2008). The study demonstrated that among maternal factors, primary education, anemia and hypertensive disorders could contribute to LBW for term birth even in the most developed area of China.