Risk factors for the increasing trend in low birth weight among live births born by vaginal delivery, Brazil

OBJECTIVE: To identify risk factors for low birth weight (LBW) among live births by vaginal delivery and to determine if the disappearance of the association between LBW and socioeconomic factors was due to confounding by cesarean section. METHODS: Data were obtained from two population-based cohorts of singleton live births in Ribeirão Preto, Southeastern Brazil. The first one comprised 4,698 newborns from June 1978 to May 1979 and the second included 1,399 infants born from May to August 1994. The risks for LBW were tested in a logistic model, including the interaction of the year of survey and all independent variables under analysis. RESULTS: The incidence of LBW among vaginal deliveries increased from 7.8% in 1978--79 to 10% in 1994. The risk was higher for: female or preterm infants; newborns of non-cohabiting mothers; newborns whose mothers had fewer prenatal visits or few years of education; first-born infants; and those who had smoking mothers. The interaction of the year of survey with gestational age indicated that the risk of LBW among preterm infants fell from 17.75 to 8.71 in 15 years. The mean birth weight decreased more significantly among newborns from qualified families, who also had the highest increase in preterm birth and non-cohabitation. CONCLUSIONS: LBW among vaginal deliveries increased mainly due to a rise in the proportion of preterm births and non-cohabiting mothers. The association between cesarean section and LBW tended to cover up socioeconomic differences in the likelihood of LBW. When vaginal deliveries were analyzed independently, these socioeconomic differences come up again.OBJETIVO: Identificar fatores de risco para o baixo peso ao nascer (BPN) entre nascidos vivos de parto vaginal e verificar se o desaparecimento da associação entre BPN e fatores socioeconômicos foi devido ao confundimento pela cesariana. MÉTODOS: Foram estudadas duas coortes de base populacional de recém-nascidos únicos de parto vaginal em Ribeirão Preto, Sudeste do Brasil. A primeira incluiu 4.698 crianças nascidas entre junho de 1978 e maio de 1979 e a segunda 1.399 crianças nascidas entre maio e agosto de 1994. Os riscos de BPN foram testados num modelo de regressão logística, incluindo interações entre ano da pesquisa e todas as variáveis independentes em análise. RESULTADOS: A incidência de BPN entre partos vaginais aumentou de 7,8% em 1978/79 para 10% em 1994 para crianças do sexo feminino, para os primogênitos, para nascidos de mães sem companheiro, para nascidos de mães que fizeram menor número de consultas pré-natais ou com menos anos de estudo e para nascidos de mães fumantes. A interação entre ano do parto e idade gestacional indicou que o risco de BPN entre os nascidos prematuros caiu de 17,8 para 8,7 em 15 anos. A média do peso ao nascer reduziu-se mais entre os filhos de famílias mais qualificadas, que tiveram o maior aumento nos nascimentos pré-termo e nas mães sem companheiro. CONCLUSÕES: O BPN entre partos vaginais aumentou principalmente devido ao incremento nos nascimentos pré-termo e nas mães sem companheiro. A associação entre cesariana e BPN tendeu a encobrir as diferenças socioeconômicas na probabilidade do BPN. Na análise dos partos vaginais isoladamente, as diferenças socioeconômicas reapareceram

Comparação entre duas coortes de mães adolescentes em município do Sudeste do Brasil

OBJECTIVE: To compare the prevalence of pregnancy among adolescents and analyze trends in some social and biological variables among two cohorts of adolescent mothers in Ribeirão Preto, Brazil, during 1978/79 and 1994. METHODS: Two cohorts of adolescent mothers were interviewed shortly after delivery, comprising 943 women in the first survey (1978/79) and 499 in the second (1994). Both surveys covered more than 98% of births in all childbirth clinics. Only singleton livebirths from adolescent mothers living in the municipality were included in the analysis. The Chi-square test was used for statistical analysis, with a 0.05 significance level. RESULTS: The percentage of adolescent mothers increased from 14.1% in 1978/79 to 17.5% in 1994 (pOBJETIVO: Comparar a prevalência de gravidez na adolescência e analisar variáveis sociobiológicas relacionadas ao binômio mãe-filho entre duas coortes de mães adolescentes de nascidos vivos em Ribeirão Preto (1978-1979 e 1994). MÉTODOS: Foram entrevistadas mães adolescentes logo após o parto, sendo 943 em 1978/79 e 499 em 1994, abrangendo nascidos vivos de parto único, de famílias residentes em Ribeirão Preto, SP. Foi utilizado o teste do qui-quadrado, com nível de significância de 0,05. RESULTADOS: O percentual de mães adolescentes aumentou de 14,1% em 1978/79 para 17,5% em 1994 (

Comparação entre duas coortes de mães adolescentes em município do Sudeste do Brasil

OBJECTIVE: To compare the prevalence of pregnancy among adolescents and analyze trends in some social and biological variables among two cohorts of adolescent mothers in Ribeirão Preto, Brazil, during 1978/79 and 1994. METHODS: Two cohorts of adolescent mothers were interviewed shortly after delivery, comprising 943 women in the first survey (1978/79) and 499 in the second (1994). Both surveys covered more than 98% of births in all childbirth clinics. Only singleton livebirths from adolescent mothers living in the municipality were included in the analysis. The Chi-square test was used for statistical analysis, with a 0.05 significance level. RESULTS: The percentage of adolescent mothers increased from 14.1% in 1978/79 to 17.5% in 1994 (pOBJETIVO: Comparar a prevalência de gravidez na adolescência e analisar variáveis sociobiológicas relacionadas ao binômio mãe-filho entre duas coortes de mães adolescentes de nascidos vivos em Ribeirão Preto (1978-1979 e 1994). MÉTODOS: Foram entrevistadas mães adolescentes logo após o parto, sendo 943 em 1978/79 e 499 em 1994, abrangendo nascidos vivos de parto único, de famílias residentes em Ribeirão Preto, SP. Foi utilizado o teste do qui-quadrado, com nível de significância de 0,05. RESULTADOS: O percentual de mães adolescentes aumentou de 14,1% em 1978/79 para 17,5% em 1994 (

Phylogeny, ultrastructure, histopathology and prevalence of Myxobolus oliveirai sp. nov., a parasite of Brycon hilarii (Characidae) in the Pantanal wetland, Brazil

This paper presents the morphological, histological and ultrastructural characteristics of Myxobolus oliveirai sp. nov., a parasite of the gill filaments in Brycon hilarii from the Brazilian Pantanal. Out of 216 B. hilariispecimens examined (126 wild and 90 cultivated), 38.1% of wild specimens (n = 48) were infected. The parasites form elongated plasmodia primarily in the tip of gill filaments, reaching about 3 mm in length. A thorough comparison with all the Myxobolus species described from South American hosts, as well as nearly all the Myxobolus species described so far is provided. Partial sequencing of the 18S rDNA gene revealed a total of 1,527 bp. The Myxobolus species parasite of B. hilarii did not match any of the Myxozoa available in GenBank. In the phylogenetic analysis, M. oliveirai sp. nov. composed a monophyletic group with eight other species: five species of Myxobolus parasites of mugilid fishes, two parasites of pangasiid and one of centrarchid. Infection prevalence values of the parasite revealed no significant differences between wet and dry seasons or between males and females. The importance of the infection to the farming of the host species is emphasized.FAPESPCEPTA - ICMBioCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Comparative study on the use of specific and heterologous microsatellite primers in the stingless bees Melipona rufiventris and M. mondury (Hymenoptera, Apidae)

Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers

Genetic variability in five populations of Partamona helleri (Hymenoptera, Apidae) from Minas Gerais State, Brazil

Partamona is a Neotropical genus of stingless bees that comprises 33 species distributed from Mexico to southern Brazil. These bees are well-adapted to anthropic environments and build their nests in several substrates. In this study, 66 colonies of Partamona helleri from five localities in the Brazilian state of Minas Gerais (São Miguel do Anta, Teixeiras, Porto Firme, Viçosa and Rio Vermelho) were analyzed using nine microsatellite loci in order to assess their genetic variability. Low levels of observed (Ho = 0.099-0.137) and expected (H e = 0.128-0.145) heterozygosity were encountered and revealed discrete genetic differentiation among the populations (F ST = 0.025). AMOVA further showed that most of the total genetic variation (94.24%) in P. helleri was explained by the variability within local populations

Understanding the clinical spectrum of complicated Plasmodium vivax malaria: a systematic review on the contributions of the Brazilian literature

The resurgence of the malaria eradication agenda and the increasing number of severe manifestation reports has contributed to a renewed interested in the Plasmodium vivax infection. It is the most geographically widespread parasite causing human malaria, with around 2.85 billion people living under risk of infection. The Brazilian Amazon region reports more than 50% of the malaria cases in Latin America and since 1990 there is a marked predominance of this species, responsible for 85% of cases in 2009. However, only a few complicated cases of P. vivax have been reported from this region. A systematic review of the Brazilian indexed and non-indexed literature on complicated cases of vivax malaria was performed including published articles, masters' dissertations, doctoral theses and national congresses' abstracts. The following information was retrieved: patient characteristics (demographic, presence of co-morbidities and, whenever possible, associated genetic disorders); description of each major clinical manifestation. As a result, 27 articles, 28 abstracts from scientific events' annals and 13 theses/dissertations were found, only after 1987. Most of the reported information was described in small case series and case reports of patients from all the Amazonian states, and also in travellers from Brazilian non-endemic areas. The more relevant clinical complications were anaemia, thrombocytopaenia, jaundice and acute respiratory distress syndrome, present in all age groups, in addition to other more rare clinical pictures. Complications in pregnant women were also reported. Acute and chronic co-morbidities were frequent, however death was occasional. Clinical atypical cases of malaria are more frequent than published in the indexed literature, probably due to a publication bias. In the Brazilian Amazon (considered to be a low to moderate intensity area of transmission), clinical data are in accordance with the recent findings of severity described in diverse P. vivax endemic areas (especially anaemia in Southeast Asia), however in this region both children and adults are affected. Finally, gaps of knowledge and areas for future research are opportunely pointed out