The epidemiologic paradox of low birth weight in Brazil

Spatial patterns of mortality in low birth weight infants at term and its determinants in the State of São Paulo, Brazil

OBJECTIVE

Low birth weight (LBW) is a public health problem strongly associated with infant mortality. This study aimed to identify the spatial distribution of infant mortality in newborns with LBW (750-2,500 g) at term (≥37 weeks of gestation), due to their being small for gestational age, analyzing its association with mother-related determinants, as well as to identify priority areas of mortality in the State of São Paulo, 2010-2019.

METHODS

Infant mortality rate was analyzed in the division of neonatal mortality and postneonatal mortality of newborns with LBW at term. The empirical Bayesian method smoothed the rates, the univariate Moran index was used to measure the degree of spatial association between the municipalities, and the bivariate Moran index was employed to identify the existence of a spatial association between the rates and the selected determinants. Thematic maps of excess risk and local Moran were prepared to identify spatial clusters, adopting 5% as a significance level.

RESULTS

The excess risk map showed that more than 30% of the municipalities had rates above the state rate. High-risk clusters were identified in the southwest, southeast, and east regions, mainly among more developed municipalities. The determinants of adolescent mothers, mothers over 34 years of age, low education, human development index, social vulnerability index, gross domestic product, physicians, and pediatric beds showed a significant association with the rates evaluated.

CONCLUSIONS

Priority areas and significant determinants associated with reduced mortality in newborns with LBW were identified, suggesting the need for intervention measures to achieve the Sustainable Development Goal.

Cesarean sections and social inequalities in 305 cities of Latin America

Background

Cesarean section (CS) is a surgical procedure that, when medically justified, can help reduce maternal and infant morbidity and mortality. Worldwide CS rates (CSR) have been increasing; Latin America has rates that are among the highest in the world.

Aim

Describe the variability of CSR across cities in Brazil, Colombia, Guatemala, Mexico, and Peru and examine the relationship of individual-level, sub-city, and city-level socioeconomic status (SES) with CSR.

Methods

We used individual level data from vital statistics over the period 2014-2016 (delivery method, mother's age and education), census data to characterize sub-city SES and city GDP per capita from other sources compiled by the SALURBAL project. We fitted multilevel negative binomial regression models to estimate associations of SES with CSR.

Results

11,549,028 live births from 1,101 sub-city units in 305 cities of five countries were included. Overall, the CSR was 52%, with a wide range across sub-cities (13-91%). Of the total variability in sub-city CSRs, 67% was within countries. In fully adjusted model higher CSR was associated with higher maternal education [(PRR (CI95%) 0.81 (0.80-0.82) for lower educational level, 1.32 (1.31-1.33) for higher level (ref. medium category)], with higher maternal age [PRR (CI95%) 1.23 (1.22-1.24) for ages 20-34 years, and 1.48 (1.47-1.49) for ages ≥ 35 years (ref. ≤19 years], higher sub-city SES [(PRR (CI95%) 1.02 (1.01-1.03) per 1SD)], and higher city GDP per capita [(PRR (CI95%): 1.03 (1.00-1.07) for GDP between 10,500-18,000, and 1.09 (1.06-1.13) for GDP 18,000 or more (ref. <10,500)].

Conclusion

We found large variability in CSR across cities highlighting the potential role of local policies on CSR levels. Variability was associated in part with maternal and area education and GDP. Further research is needed to understand the reasons for this pattern and any policy implications it may have.

The intergenerational relationship between conditional cash transfers and newborn health

Background

Lack of nutrition, inadequate housing, low education and limited access to quality care can negatively affect children’s health over their lifetime. Implemented in 2003, the Bolsa Familia (“Family Stipend”) Program (PBF) is a conditional cash transfer program targeting poor households in Brazil. This study investigates the long-term benefits of cash transfers through intergenerational transmission of health and poverty by assessing the early life exposure of the mother to the PBF.

Methods

We used data from the 100M SINASC-SIM cohort compiled and managed by the Center for Data and Knowledge Integration for Health (CIDACS), containing information about participation in the PBF and socioeconomic and health indicators. We analyzed five measures of newborn health: low (less than 2,500 g) and very low (less than 1,500 g) birth weight, premature (less than 37 weeks of gestation) and very premature (less than 28 weeks of gestation) birth, and the presence of some type of malformation (according to ICD-10 codes). Furthermore, we measured the early life exposure to the PBF of the mother as PBF coverage in the previous decade in the city where the mother was born. We applied multilevel logistic regression models to assess the associations between birth outcomes and PBF exposures.

Results

Results showed that children born in a household where the mother received BF were less likely to have low birth weight (OR 0.93, CI; 0.92-0.94), very low birth weight (0.87, CI; 0.84-0.89), as well as to be born after 37 weeks of gestation (OR 0.98, CI; 0.97-0.99) or 28 weeks of gestation (OR 0.93, CI; 0.88-0.97). There were no significant associations between households where the mother received BF and congenital malformation.

On average, the higher the early life exposure to the PBF of the mother, the lower was the prevalence of low birth weight, very low birth weight and congenital malformation of the newborn. No trend was noted for preterm birth.

Conclusion

The PBF might have indirect intergenerational effects on children’s health. These results provide important implications for policymakers who have to decide how to effectively allocate resources to improve child health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12565-7.

Incidence of low birth weight in Mexico: A descriptive retrospective study from 2008-2017

According to the WHO, low birth weight (LBW) affects 15-20% of newborns worldwide. In Mexico, there are no national, state, nor municipal estimates that inform the country's situation over time. The purpose of this study was to estimate the incidence of LBW at the national, state, and municipal levels from 2008 to 2017, and to estimate the LBW incidence based on maternal sociodemographic characteristics, prenatal care and marginalization indexes at the national level using open national data. We used spatial data analysis to georeferenced LBW incidence at the three levels of geographical disaggregation studied. At the national level, the incidence of LBW increased progressively from 6.2% (2008) to 7.1% (2017), and the country's capital represented the area with the highest incidence. Southeastern and central states reported the highest LBW regional incidence. At the municipal level, the number of municipalities with an incidence of LBW ≥8% increased in both male and female newborns. The incidence of LBW was higher as the marginalization indexes increases. The results from this study may assist in the identification of vulnerable groups and the development of public health programs and policies with an intersectoral approach that improves maternal and child nutrition.

The Determinants of Infant Mortality in Brazil, 2010-2020: A Scoping Review

Despite the implementation of social and health policies that positively affected the health of the populations in Brazil, since 2009 the country has experienced a slower decline of infant mortality. After an economic and political crisis, Brazil witnessed increases in infant mortality that raised questions about what are the determinants of infant mortality after the implementation of such policies. We conducted a scoping review to identify and summarize those determinants with searches in three databases: LILACS, MEDLINE, and SCIELO. We included studies published between 2010 and 2020. We selected 23 papers: 83% associated infant mortality with public policies; 78% related infant mortality with the use of the health system and socioeconomic and living conditions; and 27% related to individual characteristics to infant mortality. Inequalities in the access to healthcare seem to have important implications in reducing infant mortality. Socioeconomic conditions and health-related factors such as income, education, fertility, housing, and the Bolsa Família. Program coverage was pointed out as the main determinants of infant mortality. Likewise, recent changes in infant mortality in Brazil are likely related to these factors. We also identified a gap in terms of studies on a possible association between employment and infant mortality.

Health capabilities and the determinants of infant mortality in Brazil, 2004-2015: an innovative methodological framework

BACKGROUND

Despite the implementation of a set of social and health policies, Brazil has experienced a slowdown in the decline of infant mortality, regional disparities and persistent high death levels, raising questions about the determinants of infant mortality after the implementation of these policies. The objective of this article is to propose a methodological approach aiming at identifying the determinants of infant mortality in Brazil after the implementation of those policies.

METHOD

A series of multilevel panel data with fixed effect nested within-clusters were conducted supported by the concept of health capabilities based on data from 26 Brazilian states between 2004 and 2015. The dependent variables were the neonatal, the infant and the under-five mortality rates. The independent variables were the employment rate, per capita income, Bolsa Família Program coverage, the fertility rate, educational attainment, the number of live births by prenatal visits, the number of health professionals per thousand inhabitants, and the access to water supply and sewage services. We also used different time lags of employment rate to identify the impact of employment on the infant mortality rates over time, and household income stratified by minimum wages to analyze their effects on these rates.

RESULTS

The results showed that in addition to variables associated with infant mortality in previous studies, such as Bolsa Família Program, per capita income and fertility rate, other factors affect child mortality. Educational attainment, quality of prenatal care and access to health professionals are also elements impacting infant deaths. The results also identified an association between employment rate and different infant mortality rates, with employment impacting neonatal mortality up to 3 years and that a family income below 2 minimum wages increases the odds of infant deaths.

CONCLUSION

The results proved that the methodology proposed allowed the use of variables based on aggregated data that could hardly be used by other methodologies.

Urban social environment and low birth weight in 360 Latin American cities

OBJECTIVE

Using data compiled by the SALURBAL project (Urban Health in Latin America; 'Salud Urbana en América Latina') we quantified variability in low birth weight (LBW) across cities in Latin America, and evaluated the associations of socio-economic characteristics at various levels (maternal, sub-city and city) with the prevalence of LBW.

METHODS

The sample included 8 countries, 360 cities, 1321 administrative areas within cities (sub-city units) and birth registers of more than 4.5 million births for the year 2014. We linked maternal education from birth registers to data on socioeconomic characteristics of sub-cities and cities using the closest available national population census in each country. We applied linear and Poisson random-intercept multilevel models for aggregated data.

RESULTS

The median prevalence of city LBW by country ranged from a high of 13% in Guatemala to a low of 5% in Peru (median across all cities was 7.8%). Most of the LBW variability across sub-cities was between countries, but there were also significant proportions between cities within a country, and within cities. Low maternal education was associated with higher prevalence of LBW (Prevalence rate ratios (PRR) for less than primary vs. completed secondary or more 1.12 95% CI 1.10, 1.13) in the fully adjusted model. In contrast, higher sub-city education and a better city social environment index were independently associated with higher LBW prevalence after adjustment for maternal education and age, city population size and city gross domestic product (PRR 1.04 95% CI 1.03, 1.04 per SD higher sub-city education and PRR 1.02 95% CI 1.00, 1.04 per SD higher SEI). Larger city size was associated with a higher prevalence of LBW (PRR 1.06; 95% CI 1.01, 1.12).

CONCLUSION

Our findings highlight the presence of heterogeneity in the distribution of LBW and the importance of maternal education, local and broader social environments in shaping LBW in urban settings of Latin America. Implementing context-sensitive interventions guided to improve women's education is recommended to tackle LBW in the region.

Low birth weight trends in Organisation for Economic Co-operation and Development countries, 2000-2015: economic, health system and demographic conditionings

BACKGROUND

Low birth weight rates are increasing in both developed and developing countries. Although several maternal factors have been identified as associated with low birth weight, little is known of economic or organization factors influencing this increase. This study aims to ascertain the twenty-first century relationships between the contextual country factors and low birth weight rates.

METHODS

We analyse trends of low birth weight rates in Organisation for Economic Co-operation and Development (OECD) countries. Data from 2000 to 2015 were obtained from the OECD data base. Their relationships with demographic and economic variables, health habits, woman-related preventive measures, health care system organization and funding, health care work force and obstetric care were analysed using random-effects linear regression.

RESULTS

Low birth weight rates are higher in Southern Europe (7.61%) and lower in Northern Europe (4.68%). Low birth weight rates escalated about 20% in Southern Europe and to less extent in Easter Europe (7%) and Asian/Oceanian countries, while remained stable in America, Central Europe and Northern Europe. Investment in health care, private health system coverage, ratios of paediatricians and obstetricians, average length of admission due to pregnancy or birth and Caesarean section rate were associated with higher low birth weight rates. Factors associated with lower low birth weight rates were health care coverage, public health system coverage, hospitals per million inhabitants, and ratios of health care workers, physicians, midwives and nurses.

CONCLUSIONS

In OECD countries, LBW rates are related to contextual country characteristics such as GDP per capita, which is inversely related to LBW rate. Health care system factors, including health care coverage or investment in public health system, are directly associated with lower LBW rates.

Factors associated with low birth weight at term: a population-based linkage study of the 100 million Brazilian cohort

BACKGROUND

Factors associated with low birth weight at term (TLBW), a proxy for intrauterine growth restriction (IUGR), are not well-elucidated in socioeconomically vulnerable populations. This study aimed to identify the factors associated with TLBW in impoverished Brazilian women.

METHODS

Records in the 100 Million Brazilian Cohort database were linked to those in the National System of Information on Live Births (SINASC) to obtain obstetric, maternal, birth and socioeconomic data between 2001 and 2015. Multivariate logistic regression was performed to investigate associations between variables of exposure and TLBW.

RESULTS

Of 8,768,930 term live births analyzed, 3.7% presented TLBW. The highest odds of TLBW were associated with female newborns (OR: 1.49; 95% CI: 1.47-1.50), whose mothers were black (OR: 1.20; 95% CI: 1.18-1.22), had a low educational level (OR: 1.57; 95% CI: 1.53-1.62), were aged ≥35 years (OR: 1.44; 95% CI: 1.43-1.46), had a low number of prenatal care visits (OR: 2.48; 95% CI: 2.42-2.54) and were primiparous (OR: 1.62; 95% CI: 1.60-1.64). Lower odds of TLBW were found among infants whose mothers lived in the North, Northeast and Center-West regions of Brazil compared to those in the South.

CONCLUSION

Multiple aspects were associated with TLBW, highlighting the need to comprehensively examine the mechanisms underlying these factors, especially in more vulnerable Brazilian populations, in order to contribute to the elaboration of health policies and promote better conditions of life for poor and extremely poor mothers and children.

Inequalities in birth weight and maternal education: a time-series study from 1996 to 2013 in Brazil

Maternal education represents one of the most important social determinants of inequality in birth weight (BW) in developing countries. The present study sought to investigate secular trends in health inequality considering the difference in mean BW between extremes of maternal educational attainment in Brazil. Using a time-series design, data from 6,452,551 live births which occurred in all Brazilian state capitals from 1996 to 2013 were obtained from the Information System on Live Births. Secular trends of the difference in mean birth weight between low (<8 years of schooling) and high (≥12 years of schooling) educational attainment were analyzed. The main finding was that differences in mean birth weight between the two extremes of maternal educational attainment decreased over time. There was a significant decrease in mean BW in neonates born to mothers with higher educational attainment, and a slight increase in those born to mothers with lower educational attainment. One of the key factors involved in decreasing inequality was an increase in the number of antenatal visits. In view of these results, we conclude, that despite a slight increase of mean birth weight among mothers with low education, the reduction of inequality in pregnancy outcomes over time in Brazil is attributable to a worsening scenario for mothers who are better off rather than to improvements for the most vulnerable group of mothers.

Risk Factors for Neonatal Mortality in Preterm Newborns in The Extreme South of Brazil

Neonatal mortality still remains a complex challenge to be addressed. In Brazil, 60% of neonatal deaths occur among preterm infants with a gestational age of 32 weeks or less (≤32w). The aim of this study was to evaluate the factors involved in the high mortality rates among newborns with a gestational age ≤32w in a socioeconomically developed southern city in Brazil. Data on retrospective births and deaths (2000-2014) were analyzed from two official Brazilian national databases. The risk of neonatal death for all independent variables (mother's age and schooling, prenatal visits, birth hospital, delivery method, gestational age, and the newborn's sex, age, and birth year, gemelarity, congenital anomalies and birthplace) was assessed with a univariable and a multivariable model of Cox's semiparametric proportional hazards regression (p < 0.05). Data of 288,904 newborns were included, being 4,514 with a gestational age ≤32w. The proportion of these early newborns remained stable among all births, while the neonatal mortality rate for this group tended to decrease (p < 0.001). The adjusted risk was significantly for lower birthweight infants (mean 659.13 g) born from Caesarean (HR 0.58 [95% CI 0.47-0.71]), but it was significantly higher for heavier birth weight infants (mean 2,087.79) also born via Caesarean section (HR 3.71 [95% CI 1.5-9.15]). Newborns with lower weight seemed to benefit most from Cesarean deliveries. Effort towards reducing unacceptably high surgical deliveries must take into account cases that the operations may be lifesaving for mother and/or the baby.

Relationships between maternal characteristics and infant birth weight

PURPOSE

Nowadays, the importance of infant birth weight (IBW) as a key factor in determining the future of physical and mental development of children is a growing concern. The purpose of this paper is to investigate the relationship between maternal characteristics and IBW among pregnant women who were referred to health centers in Qazvin city in the year 2016.

DESIGN/METHODOLOGY/APPROACH

A descriptive-analytical study was conducted among pregnant women in 28-36 weeks of gestation who referred to healthcare centers and facilities affiliated by the Qazvin University of Medical Sciences in April-June 2016. The associations between maternal physical activity, mothers' socioeconomic status and birth weight were examined by SPSS Software Package version 16 through linear and logistic regression tests.

FINDINGS

Linear regression modeling suggested that maternal weight (p=0.001), income (p=0.04), gestational age of delivery (p=0.00) and pre-pregnancy BMI (p=0.02) were positively associated with birth weight, while occupational and heavy physical activity (p=0.003 and 0.008, respectively) were negatively associated with IBW. In this study, low birth weight infants are compared to those with normal weight belonged to mothers who have spent more time in doing heavy physical activities (OR=1.11, 95% CI 1.01-1.23). Also infants with low birth weight compared to others in the normal weight category were born from mothers with lower pre-pregnancy BMI (OR=0.65, 95% CI 0.62-0.78), gestational age of delivery (OR=0.82, 95% CI 0.79-0.86), maternal weight (OR=0.86, 95% CI 0.84-0.88) and income (OR=0.79, 95% CI 0.69-0.83).

PRACTICAL IMPLICATIONS

The study findings revealed that certain maternal characteristics could play a significant role in IBW. Despite the importance, in most of developing countries (particularly Iran), future mothers are not advised about an appropriate weight gain during pregnancy or the optimal level of physical activity in such a period of time. Therefore, counseling pregnant women and giving them proper information on appropriate perinatal care would be helpful in order to have pregnancies with optimal outcomes.

ORIGINALITY/VALUE

The authors applied several statistical methods to analyze IBW among mothers with different maternal characteristics and predict birth weight based on contributing factors.

The relationship between the different low birth weight strata of newborns with infant mortality and the influence of the main health determinants in the extreme south of Brazil

BACKGROUND

Low birth weight (LBW) newborns present different health outcomes when classified in different birth weight strata. This study evaluated the relationship of birth weight with Infant mortality (IM) through the influence of biological, social, and health care factors in a time series.

METHODS

Retrospective cohort study with data collected from Information Systems (Live Births and Mortality). The mortality trends were performed for each birth weight stratum: extremely low, < 1000 g; very low, 1000-1499 g; low, 1500-2499 g; insufficient, 2500-2999 g; adequate, 3000-3900 g; and macrosomia, > 4000 g. Chi-square tests analyzed IM rates. Sequential Poisson regression analyzed the impact of the determinant factors.

RESULTS

A total of 277,982 newborns were included in the study and 2088 died before their first year. There was a tendency for a decrease in mortality in all strata of weight. With the exception of macrosomics, all other strata had a higher risk for IM when compared with adequate birth weight. Extremely LBW newborns presented higher risk for mortality when born in a public hospital. A higher percentage of infant deaths were associated with lower maternal age and lower schooling for all strata. Prenatal care with less than three visits demonstrated a risk for IM in low, insufficient, and adequate birth weight strata. The cesarean section was a protective factor for IM in Extremely and Very LBW strata and it was a risk factor in adequate birth weight stratum.

CONCLUSIONS

LBW had a greater association with IM, especially those children of younger mothers and those born in public hospitals.

Low birthweight and preterm birth: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Despite positive changes in most maternal risk factors in Brazil, previous studies did not show reductions in preterm birth and low birthweight. We analysed trends and inequalities in these outcomes over a 33-year period in a Brazilian city.

METHODS

Four population-based birth cohort studies were carried out in the city of Pelotas in 1982, 1993, 2004 and 2015, with samples ranging from 4231 to 5914 liveborn children. Low birthweight (LBW) was defined as <2500 g, and preterm birth as less than 37 weeks of gestation. Information was collected on family income, maternal skin colour and other risk factors for low birthweight. Multivariable linear regression was used to estimate the contribution of risk factors to time trends in birthweight.

RESULTS

Preterm births increased from 5.8% (1982) to 13.8% (2015), and LBW prevalence increased from 9.0% to 10.1%, being higher for boys and for children born to mothers with low income and brown or black skin colour. Mean birthweight remained stable, around 3200 g, but increased from 3058 to 3146 g in the poorest quintile and decreased from 3307 to 3227 g in the richest quintile. After adjustment for risk factors for LBW, mean birthweight was estimated to have declined by 160 g over 1982-2015 (reductions of 103 g in the poorest and 213 g in the richest quintiles).

CONCLUSIONS

Data from four birth cohorts show that preterm births increased markedly. Mean birthweights remained stable over a 33-year period. Increased prevalence of preterm and early term births, associated with high levels of obstetric interventions, has offset the expected improvements due to reduction in risk factors for low birthweight.

Stillbirth, newborn and infant mortality: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Infant-mortality rates have been declining in many low- and middle-income countries, including Brazil. Information on causes of death and on socio-economic inequalities is scarce.

METHODS

Four birth cohorts were carried out in the city of Pelotas in 1982, 1993, 2004 and 2015, each including all hospital births in the calendar year. Surveillance in hospitals and vital registries, accompanied by interviews with doctors and families, detected fetal and infant deaths and ascertained their causes. Late-fetal (stillbirth)-, neonatal- and post-neonatal-death rates were calculated.

RESULTS

All-cause and cause-specific death rates were reduced. During the study period, stillbirths fell by 47.8% (from 16.1 to 8.4 per 1000), neonatal mortality by 57.0% (from 20.1 to 8.7) and infant mortality by 62.0% (from 36.4 to 13.8). Perinatal causes were the leading causes of death in the four cohorts; deaths due to infectious diseases showed the largest reductions, with diarrhoea causing 25 deaths in 1982 and none in 2015. Late-fetal-, neonatal- and infant-mortality rates were higher for children born to Brown or Black women and to low-income women. Absolute socio-economic inequalities based on income-expressed in deaths per 1000 births-were reduced over time but relative inequalities-expressed as ratios of mortality rates-tended to remain stable.

CONCLUSION

The observed improvements are likely due to progress in social determinants of health and expansion of health care. In spite of progress, current levels remain substantially greater than those observed in high-income countries, and social and ethnic inequalities persist.

Low birth weight and its associated factors

OBJECTIVE

To calculate the frequency and evaluate the factors associated with low birth weight.

METHODS

A retrospective study, with data from pregnant women who participated in the Programa de Atenção às Gestantes do Programa Einstein na Comunidade de Paraisópolis, between 2011 and 2014, and who returned for the postpartum evaluation of their newborns. Variables related to the pregnant woman, pregnancy, and newborn were evaluated. The outcome variable was low birth weight, defined as <2.5kg. The associations between the independent variables and low birth weight were assessed by χ2 and Mann-Whitney tests. Logistic regression models analyzed the combined effects of the independent variables on low birth weight.

RESULTS

Data of 794 pregnant women and their newborns (52.1% males) were analyzed. The age of pregnant women varied from 13 to 44 years (median of 24 years), and the majority reported being married or living in cohabitation (74.7%), and having between 9 to 11 years of schooling (53.4%). The proportion of low birth weight was 7.6% (newborn mean weight of 3.2kg) and, in multivariate analysis, presence of twinning, age group of the pregnant women (showing protection for low birth weight between ages ≥18 years and <35 years), and cesarean section were associated with low birth weight.

CONCLUSION

The proportion of low birth weight was 7.6% and twining, age of the pregnant woman, and cesarean delivery were associated with the occurrence of low birth weight.

Birth weight and its association with blood pressure and nutritional status in adolescents

OBJECTIVE

The management of children with low birth weight is not the same in countries with different resources. The authors assessed the association of birth weight with blood pressure and nutritional status in a representative sample of adolescents from a Brazilian state, aiming to identify possible consequences of these differences.

METHODS

A cross-sectional school-based study was conducted with adolescents (12-18 years) enrolled in public and private schools. Birth weight, office blood pressure, home blood pressure measurements, and nutritional status (body mass index, height z-score for the age, and waist circumference) were assessed. The association of birth weight with the outcomes (blood pressure, height, body mass index, and waist circumference) was studied through univariate and multivariable linear regression models.

RESULTS

A total of 829 adolescents with a mean age of 14.6±1.62 years were included; 43.3% were male, and 37.0% from private schools. The prevalence of low birth weight was 8.7%. Mild low height prevalence was higher among those adolescents with low/insufficient birth weight when compared to those with normal/high birth weight (11.7 vs. 4.2%; p<0.001). In the multiple linear regression analysis, for each increase of 100g in birth weight, height increased by 0.28cm (95% CI: 0.18-0.37; p<0.01). Birth weight did not influence office blood pressure and home blood pressure, body mass index, or waist circumference of adolescents.

CONCLUSIONS

Birth weight was directly associated to height, but not associated to blood pressure, body mass index, and waist circumference in adolescents from an urban area of a developing country.

Low birth weight in a municipality in the southeast region of Brazil

OBJECTIVE

to identify the prevalence of low birth weight in the city of São Paulo.

METHOD

epidemiological cross-sectional study with data collected by means of the Brazilian Live Birth Information System related to births occurred in the city of São Paulo between 2007 and 2013. Maternal, gestational, childbirth, and neonatal variables were analyzed descriptively and by association.

RESULTS

9.65% (1,342,655) of live births were underweight (mean of 3234.55 grams in the term group and 2312.17 in the pre-term group) with a mean maternal age of 27.53 years old. The risk factors identified include maternal age, not having a partner, low maternal level of education, other race rather than white, pre-term pregnancy, multiple births, low number of prenatal check-ups, and cesarean delivery.

CONCLUSION

knowledge of this evidence favors planning the care provided by defining strategies to reduce it and consequently improve maternal and infant health care.

Gender and social mobility modify the effect of birth weight on total and central obesity

BACKGROUND

Little is known about the interaction between gender and low birth weight (LBW) and lifelong social mobility as an explanation of the etiology of obesity. The aim of the present study was to evaluate total and central obesity according to gender, LBW and social mobility, within the context of the epidemiological transition in middle-income countries. We hypothesize that there are more pronounced metabolic consequences of social mobility for women born with LBW.

METHODS

We used data from a birth cohort study conducted in Ribeirão Preto, São Paulo, Brazil. Data regarding anthropometric measurements, schooling and smoking status were collected at 23-25 years of age. Social mobility was determined based on maternal and adult offspring schooling and categorized as Low-Low, Low-High and High-High. Analysis of covariance was performed to assess the association between social mobility and body mass index (BMI) or waist circumference (WC) in adulthood, stratified by LBW and gender.

RESULTS

Data on 6827 singleton pregnancies were collected at birth in 1978/79 and a sample was followed up in 2002/04. A total of 2063 subjects were included in the study. Mean age was 23.9 ± 0.7 years, 51.8% (n = 1068) were female and the LBW was 6.2% (n = 128). There was a triple interaction between social mobility, LBW and gender. Among women born without LBW, BMI and WC were higher in the Low-Low group compared to High-High schooling group. Among LBW women, BMI and WC were higher in the Low-Low group compared to the Low-High group.

CONCLUSIONS

Women born with LBW belonging to the low schooling group in early adulthood had high BMI and WC, compared to the Low-High social mobility group.

Temporal evolution of the risk factors associated with low birth weight rates in Brazilian capitals (1996-2011)

Objective

To analyze the trend of low birth weight (LBW) and its determinants in Brazilian state capitals between 1996 and 2011. We intended to determine which variables are associated with LBW during the period studied.

Methods

This is a cross-sectional study that used data from the National Information System of Live Births from 26 state capitals and Brasilia (the federal capital), divided into five geographical regions. The Average Annual Percentage of Change (AAPC) was used to assess the possible time trend in the low birth weight rates for considering all regions together and each region separately, according to each variable, and the Poisson regression was calculated in order to demonstrate time trends in low birth weight and the impact of variables (age and educational maternal level, antenatal visits, type of delivery, and gestational age) during the period. All variables were analyzed together using the Poisson regression as well.

Results

From the total of 11,200,255 live births used in this study, there was a significant reduction in the number of live births, especially in the more developed regions. The low birth weight rate was 8 %, and it was stable during the period. Considering regional trends, the rate was higher in the Southeast and South regions, and significantly higher in the North, Northeast, and Central West regions. Improvements in maternal education and antenatal care coverage reduced the risk for low birth weight in all regions. Also, there was an increase in caesarean sections in all regions, with a small impact on low birth weight rates.

Conclusions

Improvements in education and health care reduced the risk for low birth weight in all Brazilian regions during the period of study. Trends in low birth weight rates and the associated factors differ from region to region, showing different stages of demographic, epidemiological and developmental transition in Brazil. The present study was approved by the Research Ethics Committee at the Hospital de Clínicas de Porto Alegre (Protocol 120323).

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.

O crescimento e desenvolvimento frente à prematuridade e baixo peso ao nascer

<p>Objetivo: Realizar um levantamento bibliográfico acerca do crescimento e desenvolvimento de prematuros e/ou com baixo peso ao nascer. Metodologia: Utilizaram-se as bases de dados LILACS, MEDLINE e ELO. Foram encontrados 64 trabalhos: 10 publicados em 2005, 10 em 2006, 12 em 2007, 16 em 2008, 8 em 2009 e 8 em 2010. As publicações situaram-se nas áreas da medicina (59,4%), nutrição (7,8%), enfermagem (7,8%), saúde coletiva (7,8%), psicologia (6,2%), epidemiologia (4,7%), fisiologia (3,1%) e fonoaudiologia (3,1%). Resultados: Os textos encontrados permitiram organizar o conhecimento produzido segundo as seguintes categorias de análise: Fatores associados ao baixo peso ao nascer/prematuridade. Repercussões do baixo peso ao nascer/prematuridade para o crescimento e desenvolvimento e medidas de prevenção e Sobrevida dos recém-nascidos prematuros e/ou de baixo peso. Conclusão: As crianças nascidas prematuramente e com baixo peso geralmente apresentam déficit de desenvolvimento. Um acompanhamento pós-natal focado no crescimento e desenvolvimento torna-se essencial.</p>

Revista de Saúde Pública: 50 years disseminating the knowledge in nutrition

This work describes and comments on articles in the area of Public Health Nutrition published in Revista de Saúde Pública (RSP – Public Health Journal) from 1967 to 2016. We searched in the PubMed database restricted to the periodical “Revista de Saúde Pública” and using terms related to key topics in the area of Public Health Nutrition. We retrieved 742 articles and, after exclusion of duplicates and articles unrelated to the subject, we analyzed 441 articles, grouped according to subject: dental caries, anemia, hypovitaminosis A, macro/micronutrients, malnutrition, nutritional assessment, overweight/obesity, food consumption, low birthweight, and breastfeeding. We observed significant increase in the number of articles published and diversification of subjects addressed over the 50 years, representing the consistent development of the scientific field of Nutrition in Brazil. Since its inception, RSP has played an important role in the dissemination of knowledge about the main nutritional issues in Brazil.

Association between rates of caesarean section and maternal and neonatal mortality in the 21st century: a worldwide population-based ecological study with longitudinal data

Objective

Caesarean section was initially performed to save the lives of the mother and/or her baby. Caesarean section rates have risen substantially worldwide over the past decades. In this study, we set out to compile all available caesarean section rates worldwide at the country level, and to identify the appropriate caesarean section rate at the population level associated with the minimal maternal and neonatal mortality.

Design

Ecological study using longitudinal data.

Setting

Worldwide country‐level data.

Population

A total of 159 countries were included in the analyses, representing 98.0% of global live births (2005).

Methods

Nationally representative caesarean section rates from 2000 to 2012 were compiled. We assessed the relationship between caesarean section rates and mortality outcomes, adjusting for socio‐economic development by means of human development index (HDI) using fractional polynomial regression models.

Main outcome measures

Maternal mortality ratio and neonatal mortality rate.

Results

Most countries have experienced increases in caesarean section rate during the study period. In the unadjusted analysis, there was a negative association between caesarean section rates and mortality outcomes for low caesarean section rates, especially among the least developed countries. After adjusting for HDI, this effect was much smaller and was only observed below a caesarean section rate of 5–10%. No important association between the caesarean section rate and maternal and neonatal mortality was observed when the caesarean section rate exceeded 10%.

Conclusions

Although caesarean section is an effective intervention to save maternal and infant lives, based on the available ecological evidence, caesarean section rates higher than around 10% at the population level are not associated with decreases in maternal and neonatal mortality rates, and thus may not be necessary to achieve the lowest maternal and neonatal mortality.

Tweetable abstract

The caesarean section rate of around 10% may be the optimal rate to achieve the lowest mortality.

The caesarean section rate of around 10% may be the optimal rate to achieve the lowest mortality.

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

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

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.

Neonatal mortality in infants with low birth weigh

Objective To evaluate the factors associated with neonatal mortality in infant born with low birth weight. Method Cross-sectional study that analyzed data from 771 live births with low birth weight (<2500 g) in the city of Cuiabá, MT, in 2010, of whom 54 died in the neonatal period. We obtained data from the Information System on Live Births and Mortality, by integrated linkage. Results In multiple logistic regression, neonatal mortality was associated with: number of prenatal visits less than 7 (OR=3.80;CI:1,66-8,70); gestational age less than 37 weeks (OR=4.77;CI:1.48-15.38), Apgar score less than 7 at the 1st minute (OR=4.25;CI:1.84-9.81) and the 5th minute (OR=5.72,CI:2.24-14.60) and presence of congenital anomaly (OR=14.39;IC:2.72-76.09). Conclusion Neonatal mortality in infants with low birth weight is associated with avoidable factors through adequate attention to prenatal care, childbirth and infants.


[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.

Adequacy of antenatal care and its relationship with low birth weight in Botucatu, São Paulo, Brazil: a case-control study

BACKGROUND

Birth weight reflects gestational conditions and development during the fetal period. Low birth weight (LBW) may be associated with antenatal care (ANC) adequacy and quality. The purpose of this study was to analyze ANC adequacy and its relationship with LBW in the Unified Health System in Brazil.

METHODS

A case-control study was conducted in Botucatu, São Paulo, Brazil, 2004 to 2008. Data were collected from secondary sources (the Live Birth Certificate), and primary sources (the official medical records of pregnant women). The study population consisted of two groups, each with 860 newborns. The case group comprised newborns weighing less than 2,500 grams, while the control group comprised live newborns weighing greater than or equal to 2,500 grams. Adequacy of ANC was evaluated according to three measurements: 1. Adequacy of the number of ANC visits adjusted to gestational age; 2. Modified Kessner Index; and 3. Adequacy of ANC laboratory studies and exams summary measure according to parameters defined by the Ministry of Health in the Program for Prenatal and Birth Care Humanization.

RESULTS

Analyses revealed that LBW was associated with the number of ANC visits adjusted to gestational age (OR = 1.78, 95% CI 1.32-2.34) and the ANC laboratory studies and exams summary measure (OR = 4.13, 95% CI 1.36-12.51). According to the modified Kessner Index, 64.4% of antenatal visits in the LBW group were adequate, with no differences between groups.

CONCLUSIONS

Our data corroborate the association between inadequate number of ANC visits, laboratory studies and exams, and increased risk of LBW newborns. No association was found between the modified Kessner Index as a measure of adequacy of ANC and LBW. This finding reveals the low indices of coverage for basic actions already well regulated in the Health System in Brazil. Despite the association found in the study, we cannot conclude that LBW would be prevented only by an adequate ANC, as LBW is associated with factors of complex and multifactorial etiology. The results could be used to plan monitoring measures and evaluate programs of health care assistance during pregnancy, at delivery and to newborns, focusing on reduced LBW rates.

[The spatial inequality of low birth weight in Brazil]

Low birth weight (LBW) is a risk factor for neonatal and infant morbidity and mortality. In Brazil the highest percentages of low birth weight occur in regions of higher socio-economic status. The scope of this article is to ascertain the spatial distribution of low birth weight rates and the correlation with social and service indicators. The scale is ecological taking all the Brazilian states as units of analysis. The spatial analysis technique is the methodology used together with data from SINASC, IPEA and IBGE for 2009. Higher rates of low birth weight are found in the south/southeastern states (Global Moran: 0.267, p = 0.02). Clusters of the high-high type in the Southeast and of the low-low variety in states in the Amazon region are detected. The spatial inequality of low birth weight reflects the socio-economic conditions of the states. More developed regions have higher rates of low birth weight, therefore, the presence of the service and its use decrease infant mortality and increase LBW.

[Birth weight in Brazilian children under two years of age]

Low birth weight is associated with increased risk of dying in the first year of life. This study was motivated by recent changes in the determination of birth weight patterns with the advent of the perinatal epidemiological transition. We analyzed data from the Brazilian National Survey of Demographic and Health of Children and Women including only children < 24 months. Prevalence of low birth weight in Brazil was 6.1%. Risk factors included female gender, residence in the South and Southeast geographic regions, low maternal education, and maternal smoking. The low birth weight profile changed, with higher prevalence in more economically developed regions, reflecting the neonatal epidemiological transition determined by changes in patterns of childbirth care and incorporation of perinatal life support technologies, in addition to the previously known biological risks associated with poverty and misinformation.

Smoking and adverse maternal and child health outcomes in Brazil

INTRODUCTION

Numerous studies from high-income countries document the causal relationship between cigarette smoking during pregnancy and adverse maternal and child health (MCH) outcomes. Less research has been conducted in low and middle income countries, but a burgeoning literature can be found for Brazil.

METHODS

We review Brazilian studies of the prevalence of maternal smoking, the relative risk of smoking-attributable adverse MCH outcomes, and present new estimates for these outcomes, using the attributable fraction method.

RESULTS

We found that Brazilian studies of the relative risks of smoking-attributable adverse MCH outcomes were broadly consistent with previous reviews. Based on a comparison of maternal smoking over time, smoking during pregnancy has declined by about 50% over the last 20 years in Brazil. For 2008, we estimate that 5,352 cases of spontaneous abortion, 10,929 cases of preterm birth, 20,717 cases of low birth weight, and 29 cases of sudden infant death syndrome are attributable to maternal smoking. Between 1989 and 2008, the percent of smoking-attributable adverse MCH outcomes in Brazil was at least halved.

CONCLUSIONS

The results show that over a 20-year period, during which Brazil implemented numerous effective tobacco control measures, the country experienced a dramatic decrease in both maternal smoking prevalence and smoking-attributable adverse MCH outcomes. Countries that implement effective tobacco control measures can expect to reduce both maternal smoking and adverse MCH outcomes, thereby improving the public health.

Maternal education level and low birth weight: a meta-analysis

OBJECTIVE

To assess the association between maternal education level and birth weight, considering the circumstances in which the excess use of technology in healthcare, as well as the scarcity of these resources, may result in similar outcomes.

METHODS

A meta-analysis of cohort and cross-sectional studies was performed; the studies were selected by systematic review in the MEDLINE database using the following Key**words socioeconomic factors, infant, low birth weight, cohort studies, cross-sectional studies. The summary measures of effect were obtained by random effect model, and its results were obtained through forest plot graphs. The publication bias was assessed by Egger's test, and the Newcastle-Ottawa scale was used to assess study quality.

RESULTS

The initial search found 729 articles. Of these, 594 were excluded after reading the title and abstract; 21, after consensus meetings among the three reviewers; 102, after reading the full text; and three for not having the proper outcome. Of the nine final articles, 88.8% had quality ≥ six stars (Newcastle-Ottawa Scale), showing good quality studies. The heterogeneity of the articles was considered moderate. High maternal education showed a 33% protective effect against low birth weight, whereas medium degree of education showed no significant protection when compared to low maternal education.

CONCLUSIONS

The hypothesis of similarity between the extreme degrees of social distribution, translated by maternal education level in relation to the proportion of low birth weight, was not confirmed.

Série temporal de características maternas e de nascidos vivos em Niterói, RJ

OBJETIVOS: descrever a tendência temporal de características maternas, assistenciais e dos recém-nascidos, em Niterói, cidade do Estado do Rio de Janeiro. MÉTODOS: estudo ecológico, de tendência temporal, de 2000 a 2009. A fonte de dados foi o Sistema de Informações sobre nascidos vivos (SINASC). Foram descritas variações anuais de: idade materna, escolaridade, história reprodutiva, pré-natal, tipo de parto, cor, peso ao nascer e idade gestacional. RESULTADOS: a completitude da informação foi alta nos 62.449 nascidos vivos estudados. Reduziram-se os nascimentos e aumentou a primiparidade. Houve redução da gravidez adolescente (2,3% ao ano) e aumento de mães com mais de 35 anos. Melhorou a escolaridade, com redução do percentual de gestantes com menos de oito anos de estudo. Cerca de 80% das mulheres realizou sete ou mais consultas de pré-natal. O parto cesáreo apresentou tendência de aumento, realizado por 67,7% das mulheres em 2009. O baixo peso ao nascer apresentou tendência de queda de 1,1% ao ano. A prematuridade aumentou de 7,4 para 7,9%. CONCLUSÕES: Niterói apresentou evolução demográfica e social favorável. O peso ao nascer não foi muito afetado pela prematuridade. Como em outros locais do Brasil, tem se elevado o número de cesarianas.

Evolução da assistência materno-infantil e do peso ao nascer no Estado de Pernambuco em 1997 e 2006

Avaliar a evolução e a influência da assistência materno-infantil na variação do peso ao nascer no estado de Pernambuco. Os dados analisados provêm de duas pesquisas transversais da população de crianças menores de cinco anos, estudadas por inquéritos domiciliares em 1997 (n = 1906) e 2006 (n = 1555). A amostra foi calculada para assegurar a representatividade de dois estratos geoeconômicos: setores urbano e rural. Estudou-se a assistência ao pré-natal e parto e o peso ao nascer. Utilizou-se o teste do qui-quadrado para comparar as variáveis categóricas e calculou-se a diferença da média de peso ao nascer nos anos pesquisados, e os respectivos intervalos de confiança de 95%. Verificou-se importante melhora na assistência ao pré-natal e aumento do parto cesáreo. Houve uma redução significante de 112g na diferença da média de peso ao nascer no meio rural. Em 2006 o acesso a pelo menos 1 consulta de pré-natal ocorreu independente da escolaridade materna, no entanto, o acesso ao pré-natal mais adequado foi maior entre as mães de maior escolaridade, tanto em 1997, como em 2006. Apesar da expansão da assistência no pré-natal e no parto, o acesso iníquo, o excesso de intervenções médicas e o aumento da sobrevida de recém nascidos podem estar contribuindo para as variações da média de peso ao nascer no estado de Pernambuco.

Risk factors for low birth weight in Botucatu city, SP state, Brazil: a study conducted in the public health system from 2004 to 2008

BACKGROUND

Low birth weight (LBW), defined as birth weight less than 2500 g, has a complex etiology and may be a result of premature interruption of pregnancy or intrauterine growth restriction. The objective of this study was to provide information on determinants of LBW and contribute to the understanding of the problem in Brazil.

METHODS

A case-control study was conducted in Botucatu city, SP state, Brazil. The study population consisted of 2 groups with 860 newborns in each group as follows: low weight newborns (LWNB) and a control group (weight ≥ 2500 g). Secondary data from 2004 to 2008 were collected using the Live Birth Certificate (LBC) and records from medical charts of pregnant women in Basic Health Units (BHU) and in the Public University Hospital (UH). Variables were as follows: maternal socio-demographic characteristics, pregnancy and birth conditions including quality of prenatal care according to 3 criteria. They were based on parameters established by the Ministry of Health (MH), one of them, the modified Kessner Index. The multivariable analysis by logistic regression was used to evaluate the association between variables and LBW.

RESULTS

According to the analysis, the factors associated with LBW were as follows: prematurity (OR = 56.98, 95% CI 29.52-109.95), twin pregnancy (OR = 20.00, 95% CI 6.25-100.00), maternal smoking (OR = 2.12, 95% CI 1.33-3.45), maternal malnourishment (OR = 2.30, 95% CI 1.08-5.00), maternal obesity (OR = 2.30, 95% IC 1.18-4.48), weight gain during pregnancy less than 5 kg (OR = 2.63, 95% CI 1.35-5.00) and weight gain during pregnancy more than 15 kg (OR = 2.26, 95% CI 1.16-4.41). Adequacy of prenatal care visits adjusted to gestational age was less frequent in the LBW group than in the control group (68.7% vs. 80.5%, x2 p < 0.001). According to the modified Kessner Index, 64.4% of prenatal visits in the LWNB group were adequate.

CONCLUSION

LWNB are a quite heterogeneous group of infants concerning their determinants and prevention actions against LBW and the follow-up of these infants have also been very complex. Therefore, improvement in the quality of care provided should be given priority through concrete actions for prevention of LBW.

Geographical, temporal and racial disparities in late-stage prostate cancer incidence across Florida: a multiscale joinpoint regression analysis

BACKGROUND

Although prostate cancer-related incidence and mortality have declined recently, striking racial/ethnic differences persist in the United States. Visualizing and modelling temporal trends of prostate cancer late-stage incidence, and how they vary according to geographic locations and race, should help explaining such disparities. Joinpoint regression is increasingly used to identify the timing and extent of changes in time series of health outcomes. Yet, most analyses of temporal trends are aspatial and conducted at the national level or for a single cancer registry.

METHODS

Time series (1981-2007) of annual proportions of prostate cancer late-stage cases were analyzed for non-Hispanic Whites and non-Hispanic Blacks in each county of Florida. Noise in the data was first filtered by binomial kriging and results were modelled using joinpoint regression. A similar analysis was also conducted at the state level and for groups of metropolitan and non-metropolitan counties. Significant racial differences were detected using tests of parallelism and coincidence of time trends. A new disparity statistic was introduced to measure spatial and temporal changes in the frequency of racial disparities.

RESULTS

State-level percentage of late-stage diagnosis decreased 50% since 1981; a decline that accelerated in the 90's when Prostate Specific Antigen (PSA) screening was introduced. Analysis at the metropolitan and non-metropolitan levels revealed that the frequency of late-stage diagnosis increased recently in urban areas, and this trend was significant for white males. The annual rate of decrease in late-stage diagnosis and the onset years for significant declines varied greatly among counties and racial groups. Most counties with non-significant average annual percent change (AAPC) were located in the Florida Panhandle for white males, whereas they clustered in South-eastern Florida for black males. The new disparity statistic indicated that the spatial extent of racial disparities reached a peak in 1990 because of an early decline in frequency of late-stage diagnosis observed for black males.

CONCLUSIONS

Analyzing temporal trends in cancer incidence and mortality rates outside a spatial framework is unsatisfactory, since it leads one to overlook significant geographical variation which can potentially generate new insights about the impact of various interventions. Differences observed among nested geographies in Florida show how the modifiable areal unit problem (MAUP) also impacts the analysis of temporal changes.