Problem: Preterm birth is the leading cause of death and can result in significant long-term loss of physical and psychological capacity among survivors.Background: An estimated 15 million babies are born preterm every year. Prediction models based on machine learning methods have reported promising results.Aims: To identify risk factors associated with preterm birth and to develop and validate a prediction model for this outcome in a Brazilian birth cohort.Methods: Cross-sectional study of all births that occurred in Ribeirão Preto-SP and of one in three births that occurred in São Luís-MA, Brazil, in 2010. Questionnaires were applied to obtain pregnancy-related data. Multivariate adaptive regression splines were used to determine the independent variables. Preterm birth, defined as birth before 37 weeks gestational age, was the dependent variable. A random forest model was developed and its performance was evaluated by ROC analysis.Findings: The preterm birth rates were 12.7% (RP) and 14.1% (SL). The prediction and validation accuracies of the RF-based model were 91.3% and 85.5% respectively. The model can be applied starting in the third month of gestation and is more effective in identifying preterm infants with GA<31 weeks and 6 days (AUC=0.98).Discussion: It was possible to build a prediction model based on easily accessible low-cost data, without the need for complementary tests, providing results similar to those of other studies.Conclusions: Previous preterm birth and prenatal care were determinants. The use of an application for individualized patient monitoring an early stage can have positive effects on the quality of life of mother and child.

Resumo O objetivo deste estudo foi investigar a associação entre fatores sociodemográficos, estilo de vida, perfil reprodutivo maternos e atenção pré-natal e ao parto com a morbidade near miss neonatal (NMN), em quatro coortes de nascimento. Este estudo envolveu quatro coortes de nascimento: Ribeirão Preto (RP) e São Luís (SL) (2010), Pelotas 2004 (PEL04) e 2015 (PEL15). Foi considerado NMN quando presente uma ou mais das seguintes condições: peso ao nascer <1.500g, índice de Apgar <7 no quinto minuto de vida, idade gestacional <32 semanas e relato de malformações congênitas. As covariáveis foram obtidas por meio de questionários aplicados às puérperas. Para análise, foi utilizada regressão logística múltipla com abordagem hierarquizada. Algumas particularidades entre as coortes foram verificadas. Nas coortes de RP e SL foram observadas associações dos fatores dos níveis mais distais (sociodemográficas, estilo de vida e perfil reprodutivo) com o NMN. Por outro lado, em PEL os fatores proximais relacionados à atenção à saúde foram mais significativos para ocorrência de NMN. Apenas a não realização do pré-natal associou-se ao NMN em todas as coortes: RP (OR=4,27, IC95% 2,16-8,45), SL (OR=2,32, IC95% 1,09-4,94), PEL04 (OR=4,79, IC95% 1,59-14,46) e PEL15 (OR=5,10, IC95% 2,60-9,97).

Abstract The aim of this study was to investigate the association of sociodemographic factors, lifestyle, maternal reproductive profile and prenatal and childbirth care with neonatal near miss (NNM) morbidity in four birth cohorts. This study involved four population-based birth cohorts: Ribeirão Preto (RP) and São Luís (SL) (2010), Pelotas 2004 (PEL04) and 2015 (PEL15). NNM was defined when one or more of the following conditions were present: birthweight <1,500 g, 5-minute Apgar score <7, gestational age <32 weeks, and report of congenital malformations. The covariates were obtained with questionnaires applied to the puerperal women. Some particularities between cohorts were identified. In the RP and SL cohorts, factors of the more distal levels (sociodemographic, lifestyle, and reproductive profile) were associated with NNM. On the other hand, proximal factors related to healthcare were more significant for the occurrence of NNM in PEL. Only the absence of prenatal care was associated with NNM in all cohorts: RP (OR=4.27, 95%CI 2.16-8.45), SL (OR=2.32, 95%CI 1.09-4.94), PEL04 (OR=4.79, 95%CI 1.59-14.46), and PEL15 (OR=5.10, 95%CI 2.60-9.97).

Resumo O objetivo deste estudo foi investigar a associação entre fatores sociodemográficos, estilo de vida, perfil reprodutivo maternos e atenção pré-natal e ao parto com a morbidade near miss neonatal (NMN), em quatro coortes de nascimento. Este estudo envolveu quatro coortes de nascimento: Ribeirão Preto (RP) e São Luís (SL) (2010), Pelotas 2004 (PEL04) e 2015 (PEL15). Foi considerado NMN quando presente uma ou mais das seguintes condições: peso ao nascer <1.500g, índice de Apgar <7 no quinto minuto de vida, idade gestacional <32 semanas e relato de malformações congênitas. As covariáveis foram obtidas por meio de questionários aplicados às puérperas. Para análise, foi utilizada regressão logística múltipla com abordagem hierarquizada. Algumas particularidades entre as coortes foram verificadas. Nas coortes de RP e SL foram observadas associações dos fatores dos níveis mais distais (sociodemográficas, estilo de vida e perfil reprodutivo) com o NMN. Por outro lado, em PEL os fatores proximais relacionados à atenção à saúde foram mais significativos para ocorrência de NMN. Apenas a não realização do pré-natal associou-se ao NMN em todas as coortes: RP (OR=4,27, IC95% 2,16-8,45), SL (OR=2,32, IC95% 1,09-4,94), PEL04 (OR=4,79, IC95% 1,59-14,46) e PEL15 (OR=5,10, IC95% 2,60-9,97).

Abstract The aim of this study was to investigate the association of sociodemographic factors, lifestyle, maternal reproductive profile and prenatal and childbirth care with neonatal near miss (NNM) morbidity in four birth cohorts. This study involved four population-based birth cohorts: Ribeirão Preto (RP) and São Luís (SL) (2010), Pelotas 2004 (PEL04) and 2015 (PEL15). NNM was defined when one or more of the following conditions were present: birthweight <1,500 g, 5-minute Apgar score <7, gestational age <32 weeks, and report of congenital malformations. The covariates were obtained with questionnaires applied to the puerperal women. Some particularities between cohorts were identified. In the RP and SL cohorts, factors of the more distal levels (sociodemographic, lifestyle, and reproductive profile) were associated with NNM. On the other hand, proximal factors related to healthcare were more significant for the occurrence of NNM in PEL. Only the absence of prenatal care was associated with NNM in all cohorts: RP (OR=4.27, 95%CI 2.16-8.45), SL (OR=2.32, 95%CI 1.09-4.94), PEL04 (OR=4.79, 95%CI 1.59-14.46), and PEL15 (OR=5.10, 95%CI 2.60-9.97).

O objetivo deste trabalho foi avaliar a qualidade fisiológica, o conteúdo e a atividade de agentes antioxidantes presentes em sementes de soja envelhecidas durante diferentes períodos. Foram utilizadas sementes das cultivares BRS 258, BRS 262 e BRS 268, envelhecidas durante 12, 24, 36 e 48 h e sementes não envelhecidas. Após cada período de envelhecimento, as sementes foram avaliadas pelo testes de: germinação; primeira contagem e tetrazólio. Foram quantificados: compostos fenólicos totais; flavonóides totais; total de isoflavonas e atividade eliminadora do radical ABTS●+. Houve diferença entre as cultivares em relação ao vigor e viabilidade somente quando foram envelhecidas. BRS 158 e BRS 268 apresentaram melhor qualidade fisiológica de sementes em cada período de envelhecimento, porém, não apresentaram maior quantidade de isoflavonas e eficiência no sequestro dos radicais livres. Para todas as cultivares, os valores de compostos fenólicos totais, assim como os flavonóides totais, apresentaram comportamento quadrático positivo; os valores das isoflavonas permaneceram constantes e o vigor e a viabilidade apresentaram tendência contrária à atividade dos agentes antioxidantes.

The objective of this study was to evaluate physiological quality, content, and activity of antioxidants, in soybean seeds subjected to accelerated aging during different periods. Seeds of cultivars BRS 258, BRS 262 and BRS 268, subjected to accelerated aging during 12, 24, 36 and 48 hours and non-aged seeds were used. After each aging period, the seed were evaluated by tests of: germination; first count and tetrazolium. The total of phenolic compounds, total flavonoides, total of isoflavones, and activity for eliminating ABTS●+ radicals were quantified. There were differences among cultivars according to vigor and viability only after seeds were aged. Cultivars BRS 158 and BRS 268 have shown better seed physiological quality in each aging period; however, not presenting higher amounts of isoflavones and efficiency in removing free radicals. For all cultivars, the values for total of phenolic compounds, as well as total of flavonoids have shown quadratic positive behavior; the values for isoflavones remained constant and the vigor and viability showed contrary trend to activity of antioxidant agents.

Objetivou-se no presente trabalho avaliar o conteúdo de isoflavonas e a qualidade fisiológica de sementes de soja antes e após 180 dias de armazenamento. Para tal utilizou-se vinte e uma cultivares de soja CD 202, CD 206, CD 208, CD 213RR, CD 214RR, CD 215, CD 216, CD 217, CD 218, CD 221, BRS 184, BRS 185, BRS 214, BRS 244RR, BRS 245RR, BRS 246RR, BRS 255, BRS 257, BRS 258, BRS 261 e BRS 262 produzidas na safra 2005/2006 as quais foram acondicionadas em sacos de papel Kraft multifoliado e armazenadas em condições de ambiente natural de laboratório. As sementes foram avaliadas quanto a germinação, vigor (primeira contagem de germinação, envelhecimento acelerado e tetrazólio) e quanto ao teor de isoflavonas totais e suas respetivas formas agliconas (daidzeína, genisteína e gliciteína), glicosídeos (daidzina, genistina e glicitina) e seus conjugados malonil. O delineamento experimental utilizado foi o inteiramente casualizado com 6 repetições e tratamentos dispostos no esquema de parcelas subdivididas (21 cultivares x 2 tempos de armazenamento). Para a comparação de médias entre tempos de armazenamento, utilizou-se o teste F e para comparações de cultivares para cada tempo de armazenamento utilizou-se o teste de agrupamento de Scott-Knott, ambos com 95% de probabilidade. Pelos resultados foi possível concluir que os teores de isoflavonas diferenciam-se entre as cultivares e possuem comportamento distinto ao longo do armazenamento.

The objective in this research was to evaluate the isoflavone content and the physiological quality of seed from conventional and transgenic soybean cultivars before and after 180 days of storage. Twenty one soybean cultivars: CD 202, CD 206, CD 208, CD 213RR, CD 214RR, CD 215, CD 216, CD 217, CD 218, CD 221, BRS 184, BRS 185, BRS 214, BRS 244RR, BRS 245RR, BRS 246RR, BRS 255, BRS 257, BRS 258, BRS 261 and BRS 262, grown in the 2005/2006 crop season, were assayed. The seeds were packed in Kraft paper bags and stored at room temperature under laboratory conditions. Seeds were evaluated with respect to their germination and vigor (first germination count, accelerated aging and tetrazolium test) and their total isoflavone contents and respective aglycon forms (daidzein, genistein and glycitein),glycosides (daidzine, genistine and glycitine) and malonyl conjugates. A completely randomized block design with six replications with the treatments set out within a subplot scheme (21 cultivars x 2 storage periods) was used. The F-test was used to compare means between storage periods and the Scott-Knott test to compare cultivars for each storage period, both with a 95% probability. It was concluded that isoflavone contents differ between cultivars and show a distinct behavior throughout storage.