Factors associated with preterm births in southeast Brazil: a comparison of two birth cohorts born 15 years apart

Neonatal near miss and mortality: factors associated with life-threatening conditions in newborns at six public maternity hospitals in Southeast Brazil

We aimed to evaluate factors associated with cases of neonatal near miss and neonatal deaths at six public maternity hospitals in São Paulo and Rio de Janeiro States, Brazil, in 2011. A prospective hospital-based birth cohort investigated these outcomes among live births with life-threatening conditions. Associations were tested using multinomial logistic regression models with hierarchical levels. High rates of near miss were observed for maternal syphilis (52.2‰ live births) and lack of prenatal care (80.8‰ live births). Maternal black skin color (OR = 1.9; 95%CI: 1.2-3.2), hemorrhage (OR = 2.2; 95%CI: 1.3-3.9), hypertension (OR = 3.0; 95%CI: 2.0-4.4), syphilis (OR = 3.3; 95%CI: 1.5-7.2), lack of prenatal care (OR = 5.6; 95%CI: 2.6-11.7), cesarean section and hospital, were associated with near miss; while hemorrhage (OR = 4.6; 95%CI: 1,8-11.3), lack of prenatal care (OR = 17.4; 95%CI: 6.5-46.8) and hospital, with death. Improvements in access to qualified care for pregnant women and newborns are necessary to reduce neonatal life-threatening conditions.

Chlamydia trachomatis infection in young pregnant women in Southern Brazil: a cross-sectional study

This study estimated the prevalence of Chlamydia trachomatis infection during pregnancy in a sample of women up to 29 years of age in the city of Pelotas, Rio Grande do Sul State, Brazil, and investigated socio-demographic risk factors such as maternal age, marital status, maternal schooling, and family income. C. trachomatis infection was diagnosed with PCR using BD ProbeTecTM CT/GC Amplified DNA Assay. Socio-demographic, behavioral, and reproductive data were collected using structured questionnaires. All collections were performed by previously trained medical students. The study included a stratified probabilistic sample from four maternity hospitals in the city. The sample included 562 pregnant women, and prevalence of C. trachomatis infection was 12.3% (95%CI: 9.6-15.0). No significant association was identified between C. trachomatis infection and any of the target variables, including obstetric outcomes such as history of preterm delivery. Our findings in terms of low treatment adherence, only 43% of the women and 9.7% of partners, associated with high C. trachomatis prevalence, reinforce the need to implement routine screening for C. trachomatis during prenatal care. The attempt to diagnose and treat this infection after delivery, as in this study, limits the possibility of success.

[Telephone monitoring service for pregnant women and impact on prevalence of prematurity and associated risk factors in Piracicaba, São Paulo State, Brazil]

This study aims to assess the impact of a telephone monitoring service on prevalence of prematurity and to analyze associated risk factors using data on 2,739 pregnant women. Estimation was based on hierarchical multiple logistic regression, with p ≤ 0.05 for variables to remain in the model. Prevalence of preterm birth was 8.34% in monitored pregnant women and 10.18% in unmonitored women (p = 0.0058). Prevalence of preterm birth was inversely proportional to the number of monitoring calls (p < 0.0001). Variables associated with prematurity were maternal age < 19 years, history of death of two or more children, multiple pregnancy, diabetes, hypertension, fewer monitoring calls, extended standing or lifting heavy weights at work, smoking, fewer prenatal visits, no ultrasound examination, gestational diabetes, multiple pregnancy, and fetal abnormality. This low-cost strategy proved effective for reducing the preterm birth rate.

Changes in perinatal health in two birth cohorts (1997/1998 and 2010) in São Luís, Maranhão State, Brazil

The objective of this study was to analyze changes in perinatal health in two birth cohorts started in 1997/1998 and 2010, respectively, in São Luís, Maranhão State, Brazil. A total of 2,493 live born infants were included in 1997/1998 and 5,166 in 2010. Low birth weight (LBW) rate did not change (8.5% in 1997/1998 and 8.6% in 2010). Preterm birth (PTB) rate also remained stable (13.2% in 1997/1998 and 13% in 2010). Teenage deliveries and births to single mothers decreased. Maternal schooling and prenatal care coverage increased. Intrauterine growth restriction (IUGR) decreased from 13.3% to 10.6% (p < 0.001). The perinatal mortality rate decreased from 36.6 to 20.7 per 1,000 (p < 0.001) and the infant mortality rate (IMR) dropped from 28.5 to 12.8 per 1,000 (p < 0.001). The cesarean rate increased from 34.1% to 47.5% (p < 0.001). In conclusion, despite favorable changes in socio-demographic, behavioral, and health service factors and decreasing rates of IUGR and perinatal and infant mortality, LBW and PTB remained stable, while the cesarean rate increased.

Explaining racial disparities in infant health in Brazil

OBJECTIVES

We sought to quantify how socioeconomic, health care, demographic, and geographic effects explain racial disparities in low birth weight (LBW) and preterm birth (PTB) rates in Brazil.

METHODS

We employed a sample of 8949 infants born between 1995 and 2009 in 15 cities and 7 provinces in Brazil. We focused on disparities in LBW (< 2500 g) and PTB (< 37 gestational weeks) prevalence between infants of African ancestry alone or African mixed with other ancestries, and European ancestry alone. We used a decomposition model to quantify the contributions of conceptually relevant factors to these disparities.

RESULTS

The model explained 45% to 94% of LBW and 64% to 94% of PTB disparities between the African ancestry groups and European ancestry. Differences in prenatal care use and geographic location were the most important contributors, followed by socioeconomic differences. The model explained the majority of the disparities for mixed African ancestry and part of the disparity for African ancestry alone.

CONCLUSIONS

Public policies to improve children's health should target prenatal care and geographic location differences to reduce health disparities between infants of African and European ancestries in Brazil.

Interleukin-1 receptor antagonist gene polymorphism, adverse pregnancy outcome and periodontitis in Turkish women

OBJECTIVE

The aim of this study was to determine associations between interleukin (IL)-1A (+4845), IL-1B (+3954), and IL-1 receptor antagonist (RN) variable number tandem repeat polymorphisms and adverse pregnancy outcomes and periodontitis in a Turkish women.

DESIGN

A total of 156 patients, including 64 women with normal birth outcome (NB) and 92 women with preterm/low birth weight outcome (PLBW) were included in this case-control study. Within 24h after labor, maternal demographic characteristics and clinical periodontal parameters were recorded. The distribution and genotype frequencies of IL-1 were analyzed with polymerase chain reaction-restriction fragment length polymorphism assay. Statistical analyses were carried out for clinical periodontal parameters, genotype frequencies, and to identify explanatory variables for PLBW.

RESULTS

PLBW was associated with maternal age (p<0.05), irregular prenatal care (p<0.001), previous PLBW (p<0.05), and antibiotic use during pregnancy (p<0.05). Measurements of probing depth and clinical attachment level (CAL) were significantly higher in the PLBW group than in the NB group (p<0.001). PLBW was associated with IL-1RN allele 2 (p<0.001). Moreover, stepwise logistic regression analysis showed that CAL (OR 1.39, 95% CI: 1.04-1.85) and IL-1RN polymorphism (OR 7.92, 95% CI: 2.76-22.79), previous PLBW (OR 5.01, 95% CI: 1.08-23.17), age (OR 1.22, 95% CI: 1.04-1.44) were predictors found to increase the risk of PLBW (p<0.05). There was a negative association between PLBW and regular prenatal care, total number of births, use an antibiotic during pregnancy period (p<0.05).

CONCLUSION

Our study showed that, IL-1RN allele 2, periodontal disease characterized with clinical attachment loss, previous PLBW and age could be an important risk factors for PLBW.

Violência obstétrica e prevenção quaternária: o que é e o que fazer

O objetivo deste artigo é justificar a necessidade de prevenção quaternária frente à 'violência obstétrica' (VO), terminologia que agrupa todas as formas de violência e danos originados no cuidado obstétrico profissional, bem como discutir estratégias e ações de prevenção quaternária a serem realizadas pelos médicos de família e comunidade (MFC), pelas equipes de atenção primária à saúde (APS) e suas entidades associativas. A prevalência de violência obstétrica no Brasil é alta: ¼ das mulheres relata terem sofrido maus-tratos durante o atendimento ao parto, além de excesso de intervenções desnecessárias (como venóclise, ocitocina de rotina e episiotomia) e privação de uma assistência baseada em boas práticas, tais como parto em posição vertical, possibilidade de se alimentar e de se movimentar durante o trabalho de parto e presença de um acompanhante. Destaca-se o excesso crônico de cesarianas (55,6% do total de nascimentos) no Brasil, mais prevalente no setor privado (85%) do que no público (40%). Ações de prevenção quaternária dirigidas à VO são propostas e discutidas, como: (1) a elaboração (individual e coletiva) de planos de parto orientados pelas equipes de APS no pré-natal (para os quais se oferece um roteiro); (2) a introdução de outros profissionais qualificados no cuidado ao parto de risco habitual (incluindo MFC capacitados); e (3) a participação dos MFC e profissionais da APS e suas associações no movimento social e político pela “humanização” do parto, com apoio às mudanças nas maternidades já em funcionamento e às novas iniciativas de serviços de cuidado ao parto. 

Neonatal near miss in the Birth in Brazil survey

This study used data from the Birth in Brazil survey, a nationwide hospital-based study of 24,197 postpartum women and their newborns, collected between February 2011 and July 2012. A three-stage cluster sampling design (hospitals, days, women) was used consisting of stratification by geographic region, type of municipality (capital or non-capital), and type of hospital financing. Logistic regression was used to identify variables that were potential predictors of neonatal mortality and neonatal near miss indicators. After testing nineteen variables, five were chosen to compose a set of neonatal near miss indicators (birth weight of less than 1,500 g, Apgar score of less than 7 in the 5th minute of life, use of mechanical ventilation, gestational age of less than 32 weeks and congenital malformations). The neonatal near miss rate in the Birth in Brazil survey was 39.2 per thousand live births, three and a half times higher than the neonatal mortality rate (11.1 per thousand). These neonatal near miss indicators were able to identify situations with a high risk of neonatal death.

Interleukin-1 receptor antagonist levels in gingival crevicular fluid and serum in nonsmoking women with preterm low birth weight and intrauterine growth retardation

OBJECTIVE

The aim of this study was to evaluate interleukin (IL)-1 β and IL-1 receptor antagonist (IL-1ra) levels in gingival crevicular fluid (GCF) and serum (S) in nonsmoking women with normal birth (NB), preterm low birth weight (PLBW), and intra-uterine growth retardation (IUGR).

MATERIALS AND METHODS

In this unmatched case-control study design, 64 women with NB, 45 women with PLBW, and 47 women with IUGR were recruited within 24 h delivery. Clinical periodontal parameters were recorded. IL-1 β and IL-1ra levels in GCF (pg/30 s) and serum (pg/ml) of were evaluated using commercial enzyme immunoassay and ELISA kits.

RESULTS

Greater pocket depth and clinical attachment loss were observed in PLBW and IUGR women than in NB women (P < 0.05). The total amounts of IL-1ra and IL-β of GCF were higher levels in NB women than PLBW and IUGR women (P < 0.05). The lowest total amount of IL-1ra of GCF was found in IUGR women (P < 0.05). The concentrations of IL-1ra in serum samples were not statistically significant for any of the study groups (P > 0.05).

CONCLUSION

It can be suggested that worse periodontal conditions and the low levels of IL-1ra in GCF may be an important factor in adverse pregnancy outcomes.

Associação espacial entre variáveis socioeconômicas e risco relativo de nascimentos pré-termo na Região Metropolitana de São Paulo (RMSP) e na Área Metropolitana de Lisboa (AML)

A prematuridade é um dos grandes problemas de saúde pública, contribuindo fortemente para a morbi-mortalidade infantil, tanto em países em desenvolvimento como o Brasil, quanto em países europeus como Portugal. O nascido prematuro é aquele que nasce com menos de 37 semanas de gestação. Os fatores de risco individuais associados à incidência da prematuridade são conhecidos. No entanto, os fatores contextuais que podem influenciar a sua incidência têm sido pouco estudados. O principal objetivo deste estudo foi identificar o padrão espacial do risco relativo de nascimento pré-termo e possíveis agrupamentos espaciais, assim como examinar se as condições socioeconômicas estão espacialmente associadas com o risco relativo de nascimento pré-termo em duas áreas metropolitanas: Região Metropolitana de São Paulo (RMSP), no Brasil, e Área Metropolitana de Lisboa (AML), em Portugal. Foi recolhida informação relativa aos nascidos vivos (2000-2010) de mães residentes em ambas as áreas metropolitanas e às condições socioeconômicas das mães. Para análise de associação espacial entre o risco relativo de nascimentos pré-termo e as variáveis do contexto geográfico, foram aplicados testes de associação espacial global (I Moran) para ambas as áreas metropolitanas. A distribuição geográfica do risco relativo de nascimentos pré-termo ocorreu de maneira não aleatória e heterogênea tanto na RMSP como na AML: na RMSP verificou-se existir uma associação espacial global negativa significativa entre risco relativo e taxa de desemprego; na AML, foi revelada associação global positiva significativa entre o risco relativo e a taxa de analfabetismo, o índice de privação sóciomaterial e a da taxa de desemprego.

A protocol to identify non-classical risk factors for preterm births: the Brazilian Ribeirão Preto and São Luís prenatal cohort (BRISA)

Background

Preterm birth is the main cause of morbidity and mortality during the perinatal period. Classical risk factors are held responsible for only 1/3 of preterm births and no current intervention has produced an appreciable reduction of this event. It is necessary to explore new hypotheses and mechanisms of causality by using an integrated approach, collaboration among research groups and less fragmented theoretical-methodological approaches in order to detect new risk factors and to formulate more effective intervention strategies.

Methods

The study will be conducted on a convenience cohort of Brazilian pregnant women recruited at public and private prenatal health services. A total of 1500 pregnant women in São Luís, and 1500 in Ribeirão Preto, will be invited for an interview and for the collection of biological specimens from the 22nd to the 25th week of gestational age (GA). At the time of delivery they will be reinterviewed. GA will be determined using an algorithm based on two criteria: date of last menstruation (DLM) and obstetric ultrasound (OUS) performed at less than 20 weeks of GA. Illicit drug consumption during pregnancy will be determined using a self-applied questionnaire and the following instruments will be used: perceived stress scale, Beck anxiety scale, screening for depression of the Center of Epidemiological Studies (CES-D), experiences of racial discrimination, social network and social support scale of the Medical Outcomes Study and violence (Abuse Assessment Screening and violence questionnaire of the WHO). Bacterial vaginosis, urinary tract infection and periodontal disease will also be identified. Neuroendocrine, immunoinflammatory and medical intervention hypotheses will be tested. The occurrence of elective cesarean section in the absence of labor will be used as a marker of medical intervention.

Conclusion

Psychosocial, genetic and infectious mechanisms will be selected, since there are indications that they influence preterm birth (PTB). The studies will be conducted in two Brazilian cities with discrepant socioeconomic conditions. The expectation is to identify risk factors for PTB having a greater predictive power than classically studied factors. The final objective is to propose more effective interventions for the reduction of PTB, which, after being tested, might subsidize health policies.

Electronic supplementary material

The online version of this article (doi:10.1186/1742-4755-11-79) contains supplementary material, which is available to authorized users.

[Prevalence of preterm birth according to birth weight group: a systematic review]

OBJECTIVE

To estimate the prevalence of preterm birth by categories of birth weight, and to obtain an equation to correct the estimates.

METHODS

Systematic review of the Brazilian literature published from 1990 to 2012, to identify studies with primary collection of data on birth weight and gestational age. Twelve studies were selected and contributed for tabulations of preterm prevalence according to 100 g birth weight categories. These results were combined using sex-specific fractional polynomial equations and the resulting curves were compared with results from the Live Birth Information System for the years 2000, 2005, 2010 and 2011.

RESULTS

For all birth weight categories, preterm prevalence estimates based on primary studies had a higher prevalence than those of the the Live Birth Information System. The prevalence reported by the Live Birth Information System was of 7.2% in 2010, about 38.0% lower than the estimated prevalence of 11.7% obtained with the correctional equation.

CONCLUSIONS

Information reported by the Live Birth Information System on preterm prevalence does not reflect the true magnitude of the problem in Brazil, and should not be used without the correction factors proposed in the present analyses.

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.

Low birth weight in São Luís, northeastern Brazil: trends and associated factors

BACKGROUND

To analyze trends in LBW (low birth weight) rate using birth registry data and identify factors associated with LBW in São Luís comparing two birth cohorts separated by a 12-year interval.

METHODS

2,426 births were included in 1997/98 and 5,040 in 2010. The dependent variable was LBW (<2,500 g). Multiple logistic regression was performed to determine the association of independent variables with LBW. Data were also obtained from SINASC (Brazilian National Birth Registry) to analyze stillbirth and LBW rates trends from 1996 to 2010, using 3-year moving averages.

RESULTS

LBW, intrauterine growth restriction (IUGR) and preterm birth rates did not differ between the two cohorts. Despite this, birth registry data showed increasing LBW rate up to 2001, coinciding with decreasing stillbirth rate. Both stillbirth and LBW rates decreased thereafter. A significant reduction was observed in the percentage of teenage mothers, mothers with up to 4 years of education, family income up to one minimum wage and mothers who did not attend prenatal care. There was an increase in maternal age ≥35 years and schooling ≥12 years. The variables associated with LBW in 1997/98 were young maternal age (<18 years), maternal smoking during pregnancy and primiparity. Variables that remained in the adjusted model in 2010 were female gender, income <3 minimum wages, lack of prenatal care, maternal smoking during pregnancy and primiparity.

CONCLUSIONS

Although LBW rate did not differ between the two cohorts, this apparent stability masked an increase up to 2001 and a decrease thereafter. The rise in LBW rate paralleled reduction in the stillbirth rate, suggesting improvement in obstetrical and newborn care. Maternal, socioeconomic and demographic factors associated with LBW differed between the two cohorts, except for smoking during pregnancy and parity that were significantly associated with LBW in both cohorts.

Is adolescent pregnancy a risk factor for low birth weight?

OBJECTIVE

The objective of this study was to evaluate whether adolescent pregnancy is a risk factor for low birth weight (LBW) babies.

METHODS

This was a cross-sectional study of mothers and their newborns from a birth cohort in Aracaju, Northeastern Brazil. Data were collected consecutively from March to July 2005. Information collected included socioeconomic, biological and reproductive aspects of the mothers, using a standardized questionnaire. The impact of early pregnancy on birth weight was evaluated by multiple logistic regression.

RESULTS

We studied 4,746 pairs of mothers and their babies. Of these, 20.6% were adolescents (< 20 years of age). Adolescent mothers had worse socioeconomic and reproductive conditions and perinatal outcomes when compared to other age groups. Having no prenatal care and smoking during pregnancy were the risk factors associated with low birth weight. Adolescent pregnancy, when linked to marital status "without partner", was associated with an increased proportion of low birth weight babies.

CONCLUSIONS

Adolescence was a risk factor for LBW only for mothers without partners. Smoking during pregnancy and lack of prenatal care were considered to be independent risk factors for LBW.

Explaining racial disparities in infant health in Brazil

OBJECTIVES

We sought to quantify how socioeconomic, health care, demographic, and geographic effects explain racial disparities in low birth weight (LBW) and preterm birth (PTB) rates in Brazil.

METHODS

We employed a sample of 8949 infants born between 1995 and 2009 in 15 cities and 7 provinces in Brazil. We focused on disparities in LBW (< 2500 g) and PTB (< 37 gestational weeks) prevalence between infants of African ancestry alone or African mixed with other ancestries, and European ancestry alone. We used a decomposition model to quantify the contributions of conceptually relevant factors to these disparities.

RESULTS

The model explained 45% to 94% of LBW and 64% to 94% of PTB disparities between the African ancestry groups and European ancestry. Differences in prenatal care use and geographic location were the most important contributors, followed by socioeconomic differences. The model explained the majority of the disparities for mixed African ancestry and part of the disparity for African ancestry alone.

CONCLUSIONS

Public policies to improve children's health should target prenatal care and geographic location differences to reduce health disparities between infants of African and European ancestries in Brazil.

Public Health Impact of Legal Termination of Pregnancy in the US: 40 Years Later

During the 40 years since the US Supreme Court decision in Doe versus Wade and Doe versus Bolton, restrictions on termination of pregnancy (TOP) were overturned nationwide. The use of TOP was much wider than predicted and a substantial fraction of reproductive age women in the U.S. have had one or more TOPs and that widespread uptake makes the downstream impact of any possible harms have broad public health implications. While short-term harms do not appear to be excessive, from a public perspective longer term harm is conceiving, and clearly more study of particular relevance concerns the associations of TOP with subsequent preterm birth and mental health problems. Clearly more research is needed to quantify the magnitude of risk and accurately inform women with the crisis of unintended pregnancy considering TOP. The current US data-gathering mechanisms are inadequate for this important task.

Birth in Brazil: national survey into labour and birth

BACKGROUND

Caesarean section rates in Brazil have been steadily increasing. In 2009, for the first time, the number of children born by this type of procedure was greater than the number of vaginal births. Caesarean section is associated with a series of adverse effects on the women and newborn, and recent evidence suggests that the increasing rates of prematurity and low birth weight in Brazil are associated to the increasing rates of Caesarean section and labour induction.

METHODS

Nationwide hospital-based cohort study of postnatal women and their offspring with follow-up at 45 to 60 days after birth. The sample was stratified by geographic macro-region, type of the municipality and by type of hospital governance. The number of postnatal women sampled was 23,940, distributed in 191 municipalities throughout Brazil. Two electronic questionnaires were applied to the postnatal women, one baseline face-to-face and one follow-up telephone interview. Two other questionnaires were filled with information on patients' medical records and to assess hospital facilities. The primary outcome was the percentage of Caesarean sections (total, elective and according to Robson's groups). Secondary outcomes were: post-partum pain; breastfeeding initiation; severe/near miss maternal morbidity; reasons for maternal mortality; prematurity; low birth weight; use of oxygen use after birth and mechanical ventilation; admission to neonatal ICU; stillbirths; neonatal mortality; readmission in hospital; use of surfactant; asphyxia; severe/near miss neonatal morbidity. The association between variables were investigated using bivariate, stratified and multivariate model analyses. Statistical tests were applied according to data distribution and homogeneity of variances of groups to be compared. All analyses were taken into consideration for the complex sample design.

DISCUSSION

This study, for the first time, depicts a national panorama of labour and birth outcomes in Brazil. Regardless of the socioeconomic level, demand for Caesarean section appears to be based on the belief that the quality of obstetric care is closely associated to the technology used in labour and birth. Within this context, it was justified to conduct a nationwide study to understand the reasons that lead pregnant women to submit to Caesarean sections and to verify any association between this type of birth and it's consequences on postnatal health.

[Trends in the proportion of low birth weight from 1994 to 2004 in Rio Grande do Sul State, Brazil: a multilevel analysis]

The aim of this longitudinal ecological study was to analyze the trend in the proportion of low birth weight in Rio Grande do Sul State, Brazil, from 1994 to 2004 by panel data analysis and multilevel linear regression (two levels: by micro-region and time in years) to estimate risk factors associated with low birth weight. The proportion of low birth weight increased by 1.2% per year, and the multilevel model showed that the proportions differed between the micro-regions and increased over time, with the increase in the percentage of premature newborns, with the increase in the infant mortality rate, and with the increase in the cesarean rate. Among the micro-regions, the proportions of low birth weight varied positively with the urbanization rate and expenditures in the Unified National Health System and negatively with rate of participation in the workforce. According to the multilevel model, most of the variation in proportions of low birth weight was due to the effects of the micro-region of residence of the newborn's mother.

Maternal and child health in Brazil: progress and challenges

In the past three decades, Brazil has undergone rapid changes in major social determinants of health and in the organisation of health services. In this report, we examine how these changes have affected indicators of maternal health, child health, and child nutrition. We use data from vital statistics, population censuses, demographic and health surveys, and published reports. In the past three decades, infant mortality rates have reduced substantially, decreasing by 5·5% a year in the 1980s and 1990s, and by 4·4% a year since 2000 to reach 20 deaths per 1000 livebirths in 2008. Neonatal deaths account for 68% of infant deaths. Stunting prevalence among children younger than 5 years decreased from 37% in 1974-75 to 7% in 2006-07. Regional differences in stunting and child mortality also decreased. Access to most maternal-health and child-health interventions increased sharply to almost universal coverage, and regional and socioeconomic inequalities in access to such interventions were notably reduced. The median duration of breastfeeding increased from 2·5 months in the 1970s to 14 months by 2006-07. Official statistics show stable maternal mortality ratios during the past 10 years, but modelled data indicate a yearly decrease of 4%, a trend which might not have been noticeable in official reports because of improvements in death registration and the increased number of investigations into deaths of women of reproductive age. The reasons behind Brazil's progress include: socioeconomic and demographic changes (economic growth, reduction in income disparities between the poorest and wealthiest populations, urbanisation, improved education of women, and decreased fertility rates), interventions outside the health sector (a conditional cash transfer programme and improvements in water and sanitation), vertical health programmes in the 1980s (promotion of breastfeeding, oral rehydration, and immunisations), creation of a tax-funded national health service in 1988 (coverage of which expanded to reach the poorest areas of the country through the Family Health Program in the mid-1990s); and implementation of many national and state-wide programmes to improve child health and child nutrition and, to a lesser extent, to promote women's health. Nevertheless, substantial challenges remain, including overmedicalisation of childbirth (nearly 50% of babies are delivered by caesarean section), maternal deaths caused by illegal abortions, and a high frequency of preterm deliveries.

[Avoidable causes of infant mortality in Brazil, 1997-2006: contributions to performance evaluation of the Unified National Health System]

Infant deaths were classified as avoidable, non-avoidable, and resulting from ill-defined conditions, from 1997 to 2006, using the Brazilian List of Avoidable Causes of Mortality. Non-linear regression was used to calculate trends in cause-specific infant mortality rates. There was a significant decline in both avoidable deaths and deaths from ill-defined causes (p < 0.001). Avoidable deaths decreased by 37% overall. Mortality avoidable through adequate intrapartum care and adequate neonatal care decreased by 27.7% and 42.5%, respectively, while mortality avoidable through adequate prenatal care increased by 28.3%. In conclusion, health services contributed to the reduction in infant mortality. The decrease in ill-defined causes of death indicates expanded access to health services. The increase in access to intrapartum and neonatal care contributed to the reduction in infant deaths. The increase in mortality avoidable through adequate prenatal care indicates the need for improvement in prenatal care.

Effect of psychosocial stress and physical activity on preterm birth: a cohort study

AIM

To determine trimester-specific effects of risk factors for preterm birth (PTB).

METHODS

A prospective study was carried out in a district of Sri Lanka. A total of 885 pregnant mothers were recruited at equal to or less than 16 weeks of gestation and followed up until partus. Trimester-specific exposure statuses and potential confounding factors were gathered on average at the 12th, 28th, and 36th weeks of gestation. Physical activities were assessed by obtaining information about the duration of specific postures adopted per day by housewives during each trimester at home and both at home and during working hours for those who were engaged in paid employment. Psychosocial stress was assessed using the Modified Life Events Inventory and the General Health Questionnaire 30. Multiple logistic regression analysis was applied and the results were expressed as adjusted odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

Standing equal to or less than 2.5 h/day during the first or second or both trimesters (OR 1.83, 95%CI 1.03, 3.25), maternal age of <25 years (OR 1.73, 95%CI 1.02, 2.95), education up to primary school level (OR 3.30, 95%CI 1.3, 8.36) and past history of low birthweight (OR 2.52, 95%CI 1.16, 5.48) were risk factors for PTB. Psychosocial stress was not found to be a risk factor for PTB.

CONCLUSIONS

Standing equal to or less than 2.5 h/day during the early trimesters was a risk factor for PTB among uncomplicated pregnancies. Further studies are recommended to assess the trimester-specific effect of psychosocial stress on PTB.

Absence of disparities in anthropometric measures among Chilean indigenous and non-indigenous newborns

Background

Studies throughout North America and Europe have documented adverse perinatal outcomes for racial/ethnic minorities. Nonetheless, the contrast in newborn characteristics between indigenous and non-indigenous populations in Latin America has been poorly characterized. This is due to many challenges, including a lack of vital registration information on ethnicity. The objective of this study was to analyze trends in anthropometric measures at birth in Chilean indigenous (Mapuche) and non-indigenous children over a 5-year period.

Methods

We examined weight and length at birth using information available through a national data base of all birth records for the years 2000 through 2004 (n = 1,166.513). Newborns were classified ethnically according to the origins of the parents' last names.

Result

The average birthweight was stable over the 5 year period with variations of less than 20 g in each group, and with mean values trivially higher in indigenous newborns. The proportion weighing less than 2500 g at birth increased modestly from 5.2% to 5.6% in non-indigenous newborns whereas the indigenous births remained constant at 5.2%. In multiple regression analyses, adjusting flexibly for gestational age and maternal characteristics, the occurrence of an indigenous surname added only 14 g to an average infant's birthweight while holding other factors constant. Results for length at birth were similar, and adjusted time trend variation in both outcomes was trivially small after adjustment. Anthropometric indexes at birth in Chile are quite favorable by international standards.

Conclusion

There is only a trivial degree of ethnic disparity in these values, in contrast to conditions for ethnic minorities in other countries. Moreover, these values remained roughly constant over the 5 years of observation in this study.

Maternal periodontal disease and preterm or extreme preterm birth: an ordinal logistic regression analysis

BACKGROUND

Despite previous studies addressing the link between preterm or low birth weight infants and maternal periodontitis, extreme preterm births have received far less attention. This study is designed to address the possible association between maternal periodontal disease and preterm or extreme preterm birth.

METHODS

Immediately after childbirth, 1,207 women underwent an examination in which periodontal disease was assessed according to two alternative definitions: 1) four or more teeth with at least one site showing probing depth (PD) >or=4 mm and clinical attachment loss (AL) >or=3 mm, and 2) at least one site showing PD and clinical AL >or=4 mm. For each of these definitions, two types of multivariate analysis were conducted: a linear regression analysis for the number of gestation weeks, and a more specific ordinal logistic regression analysis for the ordinal variable gestation time categorized as normal (term) (n = 1,046 women) or mild-moderate (n = 146 women) or extreme preterm (n = 15 women).

RESULTS

Periodontal disease was associated with fewer weeks of gestation by linear regression (definition 1: P = 0.012; definition 2: P <0.001) and with preterm (n = 161; mild-moderate and extreme) or extreme preterm births (n = 15) by ordinal logistic regression (definition 1: odds ratio [OR] = 1.83, 95% confidence interval [CI]: 1.28 to 2.62; definition 2: OR = 2.37, 95% CI: 1.62 to 3.46).

CONCLUSION

Our findings suggest that periodontal disease is associated with a premature or extremely premature birth.

[Risk factors for pre-term birth in Londrina, Paraná State, Brazil]

The objective of this study was to identify risk factors associated with pre-term birth among live births in a hospital in Londrina, Paraná State, Brazil. Cases consisted of 328 pre-term births, and controls were 369 births with gestational age greater than 37 weeks. A multiple hierarchical logistic regression analysis was carried out. There was a significant correlation (p < 0.05) between pre-term birth and the following variables: socioeconomic status (slum residence); low age of head-of-family; maternal BMI < 19 or > 30 kg/m2; history of prematurity; history of assisted reproduction; mothers in a relationship for less than two years; maternal stress; weekly maternal alcohol consumption; insufficient prenatal care; gestational complications such as bleeding, genital tract infection, altered amniotic fluid volume, high blood pressure, and hospital admission; and twin pregnancy. Regular walks during pregnancy were a protective factor. Improved quality of prenatal care and the identification of the above factors during pregnancy may help reduce premature birth.

[Preterm births in Brazil from 1994 to 2005 according to the Information System on Live Births (SINASC)]

Monitoring preterm births is essential given their impact on infant morbidity and mortality and their economic and social costs. This article is based on data from the Information System on Live Births (SINASC), implemented in 1990 and expanded gradually to cover 90% of all births in the country. Preterm birth time trends are presented for Brazil, regions, and capitals from 1994 to 2005. At the national level, there was an increase in the preterm birth rate, accompanied by a reduction in the proportion of missing information on gestational age. The Southeast, South, and Central-West regions followed the national trend, while the preterm birth rate fell in the North and Northeast regions. We compared the findings from SINASC with those from population-based studies. The coverage and quality of SINASC has increased over time, but problems with the determination of gestational age still remain, leading to underestimation of preterm birth rates. Due to the importance of SINASC for monitoring, further efforts are needed to improve the system's accuracy.

Increase in preterm births in Brazil: review of population-based studies

OBJECTIVE

The greatest cause of infant mortality in Brazil is perinatal conditions, mostly associated with preterm delivery. The objective of the study was to evaluate the evolution of preterm delivery rates in Brazil.

METHODS

A review was conducted using the Medline and Lilacs databases, including published studies in periodicals, thesis and dissertations since 1950. Exclusion criteria were: studies related to clinical trials and those with complications at gestation and preterm delivery and care. Inclusion criteria were: population-based studies on prevalence of preterm delivery in Brazil, with representative sample of the studied population, and using primary data. Out of 71 studies found, analysis was carried out on 12.

RESULTS

The prevalence of preterm delivery found ranged from 3.4% to 15.0% in the Southern and Southeastern regions between 1978 and 2004, with a rising trend from the 1990s onwards. Studies in the Northeastern region between 1984 and 1998 found prevalences of preterm delivery ranging from 3.8% to 10.2%, also with a rising trend.

CONCLUSIONS

Data from the national live birth information system do not corroborate these trends. Rather, they show differences between the preterm rates given by this system and the rates measured in the studies included in this review. Because of the important role of preterm birth in relation to infant mortality in Brazil, it is important to identify the cause of these increases and to plan interventions that can diminish their occurrence.

Maternal-child health in Pelotas, Rio Grande do Sul State, Brazil: major conclusions from comparisons of the 1982, 1993, and 2004 birth cohorts

Important changes were observed in maternal characteristics, health care indicators, and child health during the 22 years covered by the three population-based birth cohort studies conducted in the city of Pelotas, Southern Brazil. Maternal education levels improved, cigarette smoking during pregnancy was reduced, and birth intervals became longer. Also, there were more single mothers, and maternal obesity increased. Coverage of antenatal and delivery care by professionals improved, but inductions and caesarean sections increased markedly, the latter accounting for 45% of deliveries in 2004. With regard to child health, the reductions in neonatal and infant mortality rates were modest, and the significant increase in preterm births--14.7% of all births in 2004--appears to have colluded with this stagnation. Other infant health indicators, such as immunization coverage and breastfeeding duration, showed improvements over the period. Regarding infant nutrition, malnourishment at age 12 months decreased, but the prevalence of overweight was higher in 2004. The existence of three population-based birth cohorts using comparable methodology allowed for the study of important secular trends in maternal and child health.

Preterm births, low birth weight, and intrauterine growth restriction in three birth cohorts in Southern Brazil: 1982, 1993 and 2004

Three birth cohort studies from 1982, 1993 and 2004, in Pelotas, Southern Brazil provided the data for this study of trends in preterm births, low birth weight, and intrauterine growth restriction. We found a slight increase in the period in the low birth weight prevalence from 9% to 10%. Intrauterine growth restriction decreased from 14.8% in 1982 to 9.4% in 1993, and subsequently increased to 12% in 2004, whereas preterm births increased markedly, from 6.3% in 1982 to 14.7% in 2004. This striking increment could not be explained by changes in maternal characteristics, as mothers in 2004 were heavier, smoked less during pregnancy and attended antenatal clinics more often and earlier than those of previous cohorts. However, pregnancy interruptions due either to caesarean sections or to inductions significantly increased. Caesareans increased from 28% in 1982 to 45% in 2004, and inductions were 2.5% in 1982 but 11.1% in 2004. The increase in preterms could be partially explained by the growing number of pregnancy interruptions, but there must be other causes since this increase was also observed among babies born by non-induced vaginal deliveries.

Associated factors and consequences of late preterm births: results from the 2004 Pelotas birth cohort

Although neonatal and infant mortality rates have fallen in recent decades in Brazil, the prevalence of preterm deliveries has increased in certain regions, especially in the number of late preterm births. This study was planned to investigate: (1) maternal antenatal characteristics associated with late preterm births and (2) the consequences of late preterm birth on infant health in the neonatal period and until age 3 months. A population-based birth cohort was enrolled in Pelotas, Southern Brazil, in 2004. Mothers were interviewed and the gestational age of newborns was estimated through last menstrual period, ultrasound and Dubowitz's method. Preterm births between 34 and 36 completed weeks of gestational age were classified as late preterm births. Only singleton live births from mothers living in the urban area of Pelotas were investigated. Three months after birth, mothers were interviewed at home regarding breast feeding, morbidity and hospital admissions. All deaths occurring in the first year of life were recorded. A total of 447 newborns (10.8%) were late preterms. Associations were observed with maternal age <20 years (prevalence ratio [PR] 1.3 [95% CI 1.1, 1.6]), absence of antenatal care (PR 2.4 [1.4, 4.2]) or less than seven prenatal care visits, arterial hypertension (PR 1.3 [1.0, 1.5]), and preterm labour (PR 1.6 [1.3, 1.9]). Compared with term births, late preterm births showed increased risk of depression at birth (Relative risk [RR] 1.7 [1.3, 2.2]), perinatal morbidity (RR 2.8 [2.3, 3.5]), and absence of breast feeding in the first hours after birth (PR 0.9 [0.8, 0.9]). RRs for neonatal and infant mortality were, respectively, 5.1 [1.7, 14.9] and 2.1 [1.0, 4.6] times higher than that observed among term newborns. In conclusion, in our setting, the prevention of all preterm births must be a priority, regardless of whether early or late.

Peso insuficiente ao nascer: estudo de fatores associados em duas coortes de recém-nascidos em Ribeirão Preto, São Paulo

OBJETIVO: Avaliar fatores associados ao aumento das taxas de peso insuficiente (PI) em duas coortes de recém-nascidos (RN) vivos e de parto único de Ribeirão Preto, São Paulo, separadas por 15 anos (1978/79 e 1994). MÉTODOS: Foram estudados 6.223 partos em 1978/79 e 2.522 em 1994, excluindo-se os RN de baixo peso. Associação entre PI e variáveis independentes (idade, trabalho, escolaridade e tabagismo maternos, abortos e natimortos prévios, número de filhos, situação conjugal, visitas de pré-natal, tipo de parto e hospital, categoria de internação, renda familiar, idade gestacional e sexo do RN) foi analisada por cálculo da Odds Ratio (OR) bruto e intervalo de confiança 95%, seguida de regressão logística múltipla. RESULTADOS: Em 1978/79, na análise ajustada, idade materna <20 anos (p=0,014), renda familiar <5 salários-mínimos (p=0,030), menos de quatro consultas de pré-natais (p=0,003), parto vaginal (p<0,001), sexo feminino (p<0,001), tabagismo materno (p<0,001) e prematuridade (p<0,001) estiveram associados a PI. Em 1994, os fatores associados ao PI foram: trabalho materno fora do lar (p=0,020), sexo feminino (p<0,001), tabagismo materno (p<0,001) e prematuridade (p<0,001). CONCLUSÕES: Variáveis socioeconômicas que atuaram em 1978/79 desapareceram em 1994, restando o sexo do RN, o hábito de fumar e a prematuridade nos dois períodos. Como houve diminuição do tabagismo materno e não houve modificação na proporção de nascimentos do sexo feminino, uma explicação para o aumento do PI seria o aumento nos nascimentos pré-termo entre as duas coortes.

Risk factors associated with developmental abnormalities among high-risk children attended at a multidisciplinary clinic

CONTEXT AND OBJECTIVE

Knowledge of risk factors associated with child development disorders is essential for delivering high-quality childcare. The objective here was to evaluate the relationships between risk factors and occurrences of developmental abnormalities among children attended at a reference clinic for children at risk of developmental abnormalities.

DESIGN AND SETTING

Retrospective study at a multidisciplinary reference center, Embu, São Paulo.

METHODS

All cases followed up for more than three months between 1995 and 2003 were reviewed. The risk factors assessed were low birth weight, gestational age, length of stay in neonatal ward, perinatal asphyxia, mothers age < 18 years, congenital infections, malformations and low mothers education level. Developmental abnormalities were defined according to developmental tests and assessments by the clinics professionals. The statistical analysis consisted of the chi-squared test for comparing categorical variables and a logistic regression model for multivariate analysis.

RESULTS

211 children were followed up for more than three months. Developmental abnormalities occurred in 111 (52.6%). Univariate analysis showed significant relationships between developmental abnormality and low birth weight, perinatal asphyxia, length of stay > 5 days, prematurity and mothers age 18 years and older. Low birth weight, history of perinatal asphyxia and mothers age continued to be significant in multivariate analysis.

CONCLUSIONS

Special attention must be paid to the development of low birth weight infants and/or infants with histories of neonatal complications. Low birth weight is easily assessed and should be considered to be an important marker when defining guidelines for following up child development.

Widening ethnic disparities in infant mortality in southern Brazil: comparison of 3 birth cohorts

OBJECTIVES

We analyzed trends in mortality among infants born to White and to Black or mixed-race women in 3 population-based cohorts representing all births in 1982, 1993, and 2004 in Pelotas, southern Brazil.

METHODS

Births were assessed during daily visits to all maternity hospitals. Maternal skin color was classified by the interviewers as White or Black or multi-racial. We used logistic regression to adjust for socioeconomic, demographic, and health services variables.

RESULTS

The mortality rate among infants born to White mothers declined from 30.4 per 1000 live births in 1982 to 13.9 per 1000 in 2004, compared with 53.8 per 1000 to 30.4 per 1000 among those born to Black and mixed-race mothers. Differences for neonatal mortality were even more marked, with reductions of 47% and 11% for infants born to White and Black or mixed-race women, respectively. Adjusted analyses showed that ethnic group differences in neonatal and infant mortality were partly explained by differences in poverty and prenatal care.

CONCLUSIONS

Over a 22-year period, improvements in health indicators were greater for infants born to White women than for other infants. The widening racial gap requires special attention from policymakers.

Profile of three Brazilian birth cohort studies in Ribeirão Preto, SP and São Luís, MA

We describe three birth cohort studies, respectively carried out in 1978/79 and 1994 in Ribeirão Preto, a city located in the most developed region of Brazil, and in 1997/98 in São Luís, a city located in a less developed region. The objective of the present report was to describe the methods used in these three studies, presenting their history, methodological design, objectives, developments, and difficulties faced along 28 years of research. The first Ribeirão Preto study, initially perinatal, later encompassed questions regarding the repercussions of intrauterine development on future growth and chronic adult diseases. The subjects were evaluated at birth (N = 6827), at school age (N = 2861), at the time of recruitment for military service (N = 2048), and at 23/25 years of age (N = 2063). The study of the second cohort, which started in 1994 (N = 2846), permitted comparison of aspects of perinatal health between the two groups in the same region, such as birth weight, mortality and health care use. In 1997/98, a new birth cohort study was started in São Luís (N = 2443), capital of the State of Maranhão. The 1994 Ribeirão Preto cohort and the São Luís cohort are in the second phase of joint follow-up. These studies permit comparative temporal analyses in the same place (Ribeirão Preto 1978/79 and 1994) and comparisons of two contrasting populations regarding cultural, economic and sociodemographic conditions (Ribeirão Preto and São Luís).

Factors associated with infant and adolescent mortality

Few studies have described factors associated with infant and adolescent mortality since birth. We report here mortality during a 20-year period in a birth cohort from Ribeirão Preto in order to identify birth variables that influenced mortality among infants and children between 10 and 19 years of age, the main causes of death, and the influence of social inequality at birth on death. Mothers were interviewed shortly after delivery. Social, biological and demographic information was collected, and mortality up to 19 years of age was investigated in registry systems. Of the 6748 liveborn singletons born in the municipality from 1978 to 1979, 343 died before or when 19 years of age were completed. Most of the cohort mortality (74.9%) occurred during the first year of life and 19.6% occurred from 10 to 19 years. Mortality was higher among boys. Preterm birth (hazard ratio, HR = 7.94) and low birth weight (HR = 10.15) were strongly associated with infant mortality. Other risk factors for infant mortality were: maternal age (3)35 years (HR = 1.74), unskilled manual occupation of family head (HR = 2.47), and for adolescent mortality: unskilled manual occupation of family head (HR = 9.98) and male sex (HR = 6.58). "Perinatal conditions" were the main causes of deaths among infants and "external causes" among adolescents, especially boys. Socioeconomic factors at birth, represented by occupation, influenced adolescent mortality due to external causes, which was higher among boys (7:1). The influence of social inequality at birth on death, measured by occupation, was greater in adolescence than in infancy.

Inadequate utilization of prenatal care in two Brazilian birth cohorts

Data for two birth cohorts from two Brazilian municipalities, Ribeirão Preto in 1994 and São Luís in 1997/1998, were used to identify and compare factors associated with inadequate utilization of prenatal care and to identify factors capable of explaining the differences observed between the two cities. Prenatal care was defined as adequate or inadequate according to the recommendations of the Brazilian Ministry of Health. The chi-square test and Poisson regression were used to compare differences in the inadequacy of prenatal care utilization. The percentage of inadequacy was higher in São Luís (34.6%) than in Ribeirão Preto (16.9%). Practically the same variables were associated with inadequacy in both cities. Puerperae with lower educational level, without a companion or cohabiting, who delivered in public health units, younger than 20 years, multiparae and smokers, with low family income presented higher percentages of inadequate prenatal care utilization. However, the effects of some variables differed between the two cities. The risk for inadequate use of prenatal care was higher for women attended in the public health sector in São Luís and for cohabiting women in Ribeirão Preto. The effect of the remaining factors studied did not differ between cities. The category of admission accounted for 57.0% of the difference in the inadequate use of prenatal care between cities and marital status accounted for 45.3% of the difference. Even after adjustment for all variables, part of the difference in the inadequacy of prenatal care utilization remained unexplained.

[Teenage pregnancy: Behavioral and socio-demographic profile of an urban Brazilian population]

To identify the socio-demographic behavioral profile of low-income pregnant teenagers, 1,000 adolescents admitted to a Brazilian public maternity hospital from July 24, 2001, to November 27, 2002, were interviewed. Socio-demographic and behavioral variables were assessed through a questionnaire. Over the 492 days of the study, 24.3% of admissions were adolescents (930 for childbirth and 70 for miscarriage). Mean maternal age was 17 years. Most teenagers (72.9%) lived near the hospital. 930 (93%) belonged to socioeconomic classes C, D, and E. School dropout was identified in 67.3% of the total. 80.1% of the subjects were giving birth for the first time. 81.2% had not planned the pregnancy, and 23.8% had been using some contraceptive method. 67.4% had vaginal deliveries. Some 13.3% of the newborns were premature and 15.9% had low birth weight. 17.3% of these adolescent mothers reported smoking during pregnancy, with 2.8% reporting alcohol and 1.7% illicit drugs. Teenage pregnancy is a complex phenomenon associated with various economic, educational, and behavioral factors. The study provides importance references for public policies to prevent teenage pregnancy.

Family planning: the unfinished agenda

Promotion of family planning in countries with high birth rates has the potential to reduce poverty and hunger and avert 32% of all maternal deaths and nearly 10% of childhood deaths. It would also contribute substantially to women's empowerment, achievement of universal primary schooling, and long-term environmental sustainability. In the past 40 years, family-planning programmes have played a major part in raising the prevalence of contraceptive practice from less than 10% to 60% and reducing fertility in developing countries from six to about three births per woman. However, in half the 75 larger low-income and lower-middle income countries (mainly in Africa), contraceptive practice remains low and fertility, population growth, and unmet need for family planning are high. The cross-cutting contribution to the achievement of the Millennium Development Goals makes greater investment in family planning in these countries compelling. Despite the size of this unfinished agenda, international funding and promotion of family planning has waned in the past decade. A revitalisation of the agenda is urgently needed. Historically, the USA has taken the lead but other governments or agencies are now needed as champions. Based on the sizeable experience of past decades, the key features of effective programmes are clearly established. Most governments of poor countries already have appropriate population and family-planning policies but are receiving too little international encouragement and funding to implement them with vigour. What is currently missing is political willingness to incorporate family planning into the development arena.

Could elective cesarean sections influence the birth weight of full-term infants?

CONTEXT AND OBJECTIVE

There are no studies on birth weights among full-term infants born by means of elective cesarean section. We aimed to study this in private and public hospitals.

DESIGN AND SETTING

Retrospective study at Universidade Federal do Triângulo Mineiro, Uberaba, Brazil.

METHODS

Data were collected from the municipal medical birth register of Uberaba from January to December 2000. The data obtained (maternal age, type of delivery, number of prenatal care visits and birth weight, from full-term pregnancy) from the university hospital (UH), which is a tertiary hospital that only attends patients within the National Health System (SUS), were compared with data from four private hospitals (PHs) that attend health insurance plans and private patients. Student's t test, chi2 test and multiple logistic regression were used for statistical analysis, with the significance level set at p < 0.05.

RESULTS

In the PHs, 1,100 out of 1,354 births (81.2%) were by cesarean section and in the UH, 373 out of 1,332 (28%). Birth weight increased significantly in association with increasing numbers of prenatal care visits, except for cesarean section cases in PHs. Birth weights among vaginal delivery cases in PHs were greater than in the UH (p < 0.05), but this was not observed among cesarean section cases. Multiple logistic regression showed that there was greater risk of low birth weight in PHs (odds ratio: 2.33; 95% confidence interval: 1.19 to 4.55).

CONCLUSION

Elective cesarean section performed in PHs may be associated with low birth weight among full-term infants.

Temporal trends of preterm birth subtypes and neonatal outcomes

OBJECTIVE

To describe temporal trends of preterm birth subtypes, neonatal morbidity, and hospital neonatal mortality.

METHODS

A database of 1.7 million births that occurred in 51 maternity hospitals in Latin America from 1985 to 2003 was studied. Subgroups of preterm births were classified according to the presence or absence of maternal medical or obstetric complications, spontaneous labor, preterm labor after premature rupture of membranes, induction of labor, or elective cesarean. Outcomes studied, for different periods, were prevalence of small for gestational age, neonatal morbidity, and neonatal mortality.

RESULTS

Spontaneous preterm labor without maternal complications was the most frequent subtype of preterm birth (60%), followed by premature rupture of membranes without maternal complications. Preterm births due to elective induction and delivery by elective cesarean increased markedly in the last 20 years, from 10% in 1985-1990 to 18.5% in recent years. Neonates born after spontaneous labor without maternal complications had the lowest mortality rate, but their large numbers made them responsible for one half of the preterm mortality. The induction followed by elective cesarean subgroups accounted for 13.4% of the preterm deaths between 1985 and 1990 and increased to 21.2% between 1996 and 2003.

CONCLUSION

Spontaneous labor in mothers without maternal complications is the most frequent cause of preterm births and is also the most important subgroup related to neonatal mortality. However, preterm births due to induction of labor or elective cesarean are increasing in Latin America and are becoming important contributors to neonatal mortality.

[Risk factors for repetition of low birth weight, intrauterine growth retardation, and prematurity in subsequent pregnancies: a systematic review]

With the aim of collecting evidence on repetition of low birth weight, intra-uterine growth retardation (IUGR), and prematurity in successive pregnancies, a systematic review was conducted on MEDLINE, LILACS, PAHO, and MedCarib from 1965 to 2004, using as descriptors: "low birth weight and recurrence, repetition or previous", "risk factors and repetition, recurrence or previous LBW", "IUGR and recurrence, repetition or previous", "risk factors and repetition, recurrence or previous IUGR", "prematurity and recurrence, repetition or previous", and "risk factors and repetition, recurrence or previous prematurity". Of 24 studies, 18 were excluded due to inconsistency between the title and the actual subject investigated (obstetric history as a risk factor rather than a selection criterion). The most important risk factors associated with repetition of low birth weight were maternal age > 30 years, smoking, short inter-gestational interval, and black skin color; those associated with IUGR were maternal age < 20 or > 35 years, low maternal education, high blood pressure, drug addiction, and non-technical/non-professional paternal occupation; and with preterm birth, premature rupture of membranes, chorioamnionitis, preeclampsia, preterm labor, and inter-gestational interval less than 12 months.

Atherogenic lipid profile of Brazilian near-term newborns

Cardiovascular disease is the primary cause of death in Brazil. Recent studies have shown that low birth weight and preterm birth are linked to a higher prevalence of cardiovascular disease. The aim of the present study was to compare the levels of lipids and apolipoproteins and atherogenic indexes between term and near-term newborn infants. A sample of umbilical cord blood was obtained from 135 newborns (66 males) divided into two groups: 25 near-term neonates (35-36.6 weeks of gestational age) and 110 term neonates (37-42 weeks of gestational age). The total cholesterol concentrations were higher in the near-term neonates than in the term group (94.04 +/- 8.02 vs 70.42 +/- 1.63 mg/dl, P < 0.01), due to an increase in the LDL-cholesterol fraction in the near-term group (57.76 +/- 6.39 vs 34.38 +/- 1.29 mg/dl, P < 0.001). The atherogenic indexes (total cholesterol/HDL-cholesterol, LDL-cholesterol/HDL-cholesterol and apolipoprotein B/apolipoprotein A-I) were higher in the near-term group (P < 0.001, P < 0.001, and P < 0.05, respectively). The gestational age of the newborns was inversely correlated with total cholesterol and LDL-cholesterol, and also with the total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol indexes. These findings demonstrate that the lipid profile is worse in the group of near-term neonates compared with the term group. Future studies are needed to determine if this atherogenic profile in near-term neonates can affect body metabolism, increasing the risk for cardiovascular diseases in adult life.

Risk factors for intrauterine growth restriction: a comparison between two Brazilian cities

In Brazil, similar intrauterine growth restriction (IUGR) rates were observed between cities with distinct levels of socioeconomic development, challenging the current knowledge that higher rates of IUGR would necessarily be observed in poorer areas than in wealthier ones. Ribeirão Preto, a city located in the most developed area in Brazil, showed an IUGR rate of 18% in 1994, whereas this rate was 18.5% in 1997/1998 in São Luis, located in one of the poorest areas in the country. The objective of this study was to compare risk factors for IUGR in these two cities and to identify factors that are responsible for this unexpected lack of difference between the rates. Using data from two birth cohorts, including 2839 neonates who were from Ribeirão Preto and born in 1994 and 2439 neonates who were from São Luis and born in 1997/1998, a multivariable analysis was conducted to assess changes in the risk for IUGR in the poorer city compared with the wealthier one in a combined model, adjusting for some risk factors for IUGR. The wealthier city showed higher rates of maternal smoking, attendance in the private sector, and obstetric interventions than the less developed one. Differences in maternal smoking and obstetric interventions were possibly responsible for the similarity of the rates between cities. It seems that early detection of IUGR followed by cesarean section in the wealthier city is associated with increased low birth weight and IUGR rates but reduced stillbirth and infant mortality rates.

The challenge of reducing neonatal mortality in middle-income countries: findings from three Brazilian birth cohorts in 1982, 1993, and 2004

BACKGROUND

Middle-income countries will need to drastically reduce neonatal deaths to achieve the Millennium Development Goal for child survival. The evolution of antenatal and perinatal care indicators in the Brazilian city of Pelotas from 1982 to 2004 provides a useful case study of potential challenges.

METHODS

We prospectively studied three birth cohorts representing all urban births in 1982, 1993, and from January to July, 2004. The same methods were used in all three studies.

FINDINGS

Despite improvements in maternal characteristics, prevalence of preterm births increased from 6.3% (294 of 4665) in 1982 to 16.2% (342 of 2112) in 2004, corresponding to a 47 g reduction in mean birthweight. Average number of antenatal visits in 2004 was 8.3 per woman, but quality of care was still inadequate--97% of women had an ultrasound scan, but only 1830 (77%) had a vaginal examination and 559 of 1748 non-immunised women did not receive tetanus toxoid. Rate of caesarean sections increased greatly, from 28% (1632 of 5914) in 1982 to 43% (1039 of 2403) in 2004, reaching 374 of 456 (82%) of all private deliveries in 2004. The increased rate of preterm births seemed to result largely from caesarean sections or inductions. Newborn care improved, and gestational-age-specific mortality rates had fallen by about 50% since 1982. As a result, neonatal mortality rates had been stable since 1990, despite the increase in preterm deliveries.

INTERPRETATION

Excessive medicalisation--including labour induction, caesarean sections, and inaccurate ultrasound scans--led by an unregulated private sector with spill-over effects to the public sector, might offset the gains resulting from improved maternal health and newborn survival. These challenges will have to be faced by middle-income countries striving to achieve the child survival Millennium Development Goal.

Why are the low birthweight rates in Brazil higher in richer than in poorer municipalities? Exploring the epidemiological paradox of low birthweight

Socio-economic disadvantage is usually associated with low birthweight (LBW). However, it has been shown that Mexican Americans, despite being economically less advantaged, present LBW rates that are similar to or lower than those found among white women in the US. This fact has been called 'the epidemiological paradox of low birthweight'. Natality data from Brazil revealed the existence of a similar paradox: LBW rates are higher in more developed than in less developed regions within the country. In this study, data from two population-based cohort studies carried out in the nineties, including 2439 births in Sao Luis, a poor city in north-eastern Brazil, and 2839 births in Ribeirao Preto, a socio-economically well-off city in south-eastern Brazil, were used to explore this paradox. The method proposed by Wilcox and Russell and a graphic analysis of the frequency distribution of birthweight according to gestational age were used to provide indirect information about possible gestational age misclassification. Contrary to expectations, the LBW rate was higher in Ribeirao Preto than in Sao Luis (10.7 vs. 7.6%, P <0.001), while preterm birth (PTB) rate (12.7 vs. 12.1%, P=0.520) and percentage of small-for-gestational-age (SGA) infants (12.5 vs. 13.5%, P=0.290) were similar for the two cities. However, SGA rate among preterm infants was higher in Ribeirao Preto (16.4 vs. 9.8%, P=0.014). A bimodal distribution of birthweight was observed for children with less than 32 weeks in Sao Luis. As estimated by the Wilcox and Russell method, the residual distribution was greater in Ribeirao Preto than in Sao Luis (3.4 vs. 2.4%). Part of the LBW paradox observed for the two cities was due to the higher PTB rate and higher number of preterm SGA infants in Ribeirao Preto. Factors such as greater medical intervention in preterm newborns close to the end of pregnancy in more developed municipalities, artefacts in the determination of gestational age, and the under-registration of livebirths and registration of livebirths as stillbirths in less developed municipalities may explain why LBW rates in Brazil are higher in richer than in poorer municipalities.

Trends in prenatal care use and low birthweight in southeast Brazil

OBJECTIVES

We investigated trends in prenatal care use and its association with low birthweight in a developing country.

METHODS

We examined data from 2 southeast Brazilian cohort surveys, 1 conducted in 1978-1979 and the other in 1994.

RESULTS

Socioeconomic inequalities in prenatal care use increased during the 15-year period of 1979-1994. Although prenatal care use increases paralleled increases in low birthweight rate during this period, having no prenatal care was associated with higher risk of low birthweight in both surveys. Inadequate prenatal care use was also associated with higher risk of low birthweight in 1978-1979 only.

CONCLUSIONS

Increasing low birthweight rates among women who adequately used prenatal care may be causing a bias by reducing the estimates of the effect of inadequate prenatal care use on low birthweight rates.

Risk factors for preterm births in São Luís, Maranhão, Brazil

Preterm birth continues to be one of the main causes of neonatal morbidity and mortality. The objective of the present study was to identify risk factors for preterm birth in São Luís, Maranhão, Brazil. The sample consisted of hospital births at 10 public and private hospitals from March 1, 1997 to February 28, 1998. A total of 2,443 live births were randomly selected, excluding multiple deliveries and stillbirths. Preterm birth rate in São Luís was 12.7%. Risk factors for preterm delivery were maternal age below 18 years, family income equal to or less than one minimum wage/ month, primiparity, vaginal delivery at a public hospital, single mothers (or living without a partner), and absence of prenatal care. The following factors remained associated with preterm birth after multivariate analysis to control for confounding: maternal age below 18 years (OR = 1.9), primiparity (OR = 1.5), and failure to appear for scheduled prenatal care visits (OR = 1.5).