Microbiota y perfil inmunológico vaginal de la embarazada propensa a parto prematuro por infección bacteriana ascendente: revisión narrativa / Microbiota and vaginal immunological profile of pregnant women prone to premature birth due to ascending bacterial infection: narrative review

El parto prematuro (PP) es la principal causa de morbilidad/mortalidad perinatal en el mundo. La infección intrauterina es el origen más frecuente del PP espontáneo (PPE) en un hospital público de Chile. Existe evidencia de que la infección bacteriana ascendente (IBA) produce la infección/inflamación intraamniótica, el PPE y los resultados adversos maternos y perinatales. Esta revisión narrativa incluye revisiones sistemáticas y estudios de cohorte o de caso-control sobre la microbiota y el perfil inmunológico existente en el tracto genital inferior (TGI) de la embarazada propensa a PPE por IBA. Existe consenso en que en la microbiota del TGI de esta gestante hay colonización vaginal con baja abundancia de lactobacilos y/o disminución de su calidad, por diferencias raciales y/o geográficas o genéticas y una desregulación de los mecanismos inmunológicos del TGI. Estas respuestas se presentan con mayor intensidad en pacientes con factores de riesgo del huésped, como diabetes, obesidad, estrés, ansiedad y depresión, originando infecciones recurrentes del TGI, responsables del PPE y de los resultados perinatales. El conocimiento del comportamiento de la microbiota y del sistema inmunitario en estos casos permitirá tener terapias eficaces para prevenir el PPE y la morbilidad/mortalidad neonatal por IBA.

Preterm delivery (PD) is the leading cause of perinatal morbidity/mortality in the world. Intrauterine infection is the most frequent origin of spontaneous PD (SPD) in a public hospital in Chile. There is evidence that vaginal ascending bacterial infection (ABI) causes intra-amniotic infection/inflammation, SPD, and adverse maternal and perinatal outcomes. This narrative review includes systematic reviews and cohort or case-control studies on the microbiota and immunological profile existing in the lower genital tract (LGT) of pregnant women prone to SPD due to ABI. There is consensus that in the LGT microbiota of this pregnant woman there is vaginal colonization with low abundance of Lactobacilli and/or decreased quality, due to racial and/or geographic, or genetic differences and dysregulation of immunological mechanisms of the LGT. These responses occur with greater intensity in patients with host risk factors, such as diabetes, obesity, stress, anxiety, and depression, causing recurrent LGT infections responsible for SPD and perinatal outcomes. Knowledge of the behavior of the microbiota and the immune system in these cases will allow effective therapies to prevent SPD and neonatal morbidity/mortality due to ABI.

Evaluación de la cervicometría e índice de bishop para diagnóstico de amenaza de parto prematuro. Servicio de alto riesgo obstétrico. Hospital de la Mujer, enero ­ marzo de 2019 / Assessment of cervicometry and bishop score for the diagnosis of threatened preterm labor. High-risk obstetric service. Hospital de la Mujer, january­march 2019

OBJETIVO: determinar la validez y fiabilidad de la cervicometría y el índice de Bishop para diagnóstico de amenaza de parto prematuro MATERIAL Y MÉTODOS: estudio retrospectivo, cuantitativo, analítico para validación de un test diagnóstico. MUESTRA: el estudio incluye 185 embarazadas con feto único, de 22 a 37 semanas con estudio de cervicometría, en el periodo de enero a marzo del 2019. RESULTADOS: la frecuencia de parto prematuro en gestantes con diagnóstico de amenaza de parto prematuro fue de 27 % con mayor prevalencia en mujeres con 4 o más partos. La evaluación de la cervicometría para diagnóstico de amenaza de parto prematuro tiene una sensibilidad de 66.0%, especificidad 94.8%, Valor Predictivo (+) 82.5%, y Valor Predictivo (-) 88.3%. La evaluación del índice de Bishop una sensibilidad de 4.0%, especificidad 99.3%, Valor Predictivo (+) 66.7% y Valor Predictivo (-) 73.6%. El índice de concordancia entre la cervicometría y el índice de Bishop es ínfima de 0.017. El área bajo la curva ROC para cervicometría en relación con el diagnóstico final de parto prematuro fue de 0.905, con un mejor punto de corte 30.5 mm que corresponde a una sensibilidad de 90.4 % y una especificidad de 78.0 %. CONCLUSIÓN: se concluye que la concordancia entre la cervicometría y el índice de Bishop para diagnóstico de amenaza de parto prematuro es ínfima

In this study, the researchers aimed to determine the validity and reliability of cervicometry and the Bishop score for diagnosing threatened preterm labor in the high-risk obstetric service at the Hospital de la Mujer in La Paz during the period from January to March 2019. The study included pregnant women, and the results showed varying sensitivities and specificities for cervicometry and the Bishop score. The concordance between these two methods was found to be minimal. OBJECTIVE: to determine the validity and reliability of cervicometry and the Bishop score to diagnose threatened preterm labor. MATERIAL AND METHODS: retrospective, quantitative, and analytical study to validate a diagnostic test. SAMPLE: the study included 185 pregnant women with a single fetus, at gestational ages between 22 and 37 weeks, who underwent cervicometry assessment during the period from January to March 2019. RESULTS: the frequency of preterm labor in pregnant women diagnosed with threatened preterm labor was 27%, with higher prevalence in women with 4 or more previous deliveries. Cervicometry evaluation to diagnose threatened preterm labor showed a sensitivity of 66.0%, specificity of 94.8%, positive predictive value (+) of 82.5%, and negative predictive value (-) of 88.3%. Bishop score evaluation had a sensitivity of 4.0%, a specificity of 99.3%, a positive predictive value (+) of 66.7%, and a negative predictive value (-) of 73.6%. The concordance index between cervicometry and the Bishop score was minimal (0.017). The area under the ROC curve for cervicometry in relation to the final diagnosis of preterm labor was 0.905, with an optimal cutoff point of 30.5 mm, corresponding to a sensitivity of 90.4% and specificity of 78.0%. CONCLUSION: the concordance between cervicometry and the Bishop score to diagnose threatened preterm labor is minimal

Endocannabinoid regulation in the cervix during pregnancy: insights into molecular mechanisms of premature labor.

In brief: The cervix plays a crucial role not only in the maintenance of pregnancy but also during delivery, when it undergoes extensive changes. This study highlights the involvement of the endocannabinoidome in cervical remodeling, emphasizing its relevance in the shift from a nonpregnant to pregnant state and its potential contribution to preterm delivery in inflammatory contexts. Abstract: During pregnancy, the main role of the cervix is to isolate the fetus from outside pathogens and maintain the relatively closed system of uterine gestation. Conversely, toward the end of pregnancy, the cervix must be remodeled to increase flexibility and allow the delivery. This process is called cervical remodeling and dysregulation of the process plays a role in premature delivery. The endocannabinoidome plays an important role in several reproductive events; however, its function on cervical tissue throughout pregnancy is poorly understood. The goal of this study was to evaluate the presence and participation of the endocannabinoidome in lipopolysaccharide (LPS)-induced cervical changes. Therefore, we evaluated key components of the endocannabinoidome in cervical tissue from nonpregnant mice and pregnant mice with and without LPS treatment. Using mass spectrometric analysis, we found an increase in anandamide and 2-arachidonoylglycerol in the cervix of pregnant mice when compared to nonpregnant mice. We have also found a reduction in FAAH protein expression in these tissues. Furthermore, when treated with LPS, we observed a reduction in the cervical immunostaining with anti-CB1 and anti-CB2 antibodies. Likewise, using cervix explants from pregnant mice, we found that LPS significantly increased cervical metalloprotease activity and cyclooxygenase 2, which were subsequently modulated by cannabinoid receptor antagonists. Collectively, our findings suggest that an LPS-induced imbalance of cervix endocannabinoidome likely contributes to premature cervical remodeling, which is part of the key components that contribute to premature delivery.

Temporal analysis of maternal, care and newborns characteristics in the city of Guarapuava-PR from 2010 to 2019 / Análise temporal de características maternas, assistenciais e de nascidos vivos do município de Guarapuava-PR de 2010 a 2019

Abstract Objectives: to analyze the temporal trend in maternal, care and newborns characteristics, in the city of Guarapuava, Paraná, Brazil in the period of 2010 to 2019. Methods: ecological temporal tendency study is based on Sistema de Informações sobre Nascidos Vivos (Live Birth Information System). To verify changes on the topics, the Prais-Winsten generalized linear regression was applied. Results: data from 28,919 live births were analyzed in 2019, 15.9% of the pregnancies were adolescents, 49.8% were cesarean deliveries and 9.2% were premature childbirths. A reduction in teenage pregnancy was observed, with annual percentage variation (APV) for mothers aged ten to 14 being -0.14% (p=0.005) and 15 to 19 years old -0.82% (p=0.004); there was an increase in mothers' schooling, with an APV of 60.09% (p=0.026) for eight to 11 years of schooling and 11.27% (p<0.001) for 12 or more; there was an increase of 15.33% (p<0.001) for seven or more prenatal consultations and a decrease in the Apgar classifications considering the risk, with scores from zero to two in the 1st minute with an APV=-0.12 (p=0.010) and scores from three to five in the 5th minute with APV=-0.07 (p=0.011). Conclusions: The city of Guarapuava presents important decreased tendencies in early pregnancy and an increase in mothers' schooling, besides the changes regarding the conditions in which their children are born and how they are welcomed.

Resumo Objetivos: analisar a tendência temporal de características maternas, assistenciais e dos recém-nascidos do município de Guarapuava-PR no período de 2010 a 2019. Métodos: estudo ecológico de tendência temporal com dados do Sistema de Informações sobre Nascidos Vivos. Para verificar mudanças nas características avaliadas, utilizou-se regressão linear generalizada de Prais-Winsten. Resultados: analisaram-se dados de 28.919 nascidos vivos; em 2019, 15,9% das gestações foram de adolescentes, 49,8% dos partos cesáreos e 9,2% partos prematuros. Observou-se redução da gravidez na adolescência, com variação percentual anual (VPA) para mães com dez a 14 anos sendo -0,14% (p=0,005) e 15 a 19 anos -0,82% (p=0,004); aumento da escolaridade das mães, com VPA de 60,09% (p=0,026) para oito a 11 anos de estudo e 11,27% (p<0,001) para 12 ou mais; aumento de 15,33% (p<0,001) para sete ou mais consultas de pré-natal realizadas pelas gestantes e queda nas classificações de Apgar consideradas de risco, com notas zero a dois no 1º minuto com VPA=-0,12 (p=0,010) e notas três a cinco no 5º minuto com VPA=-0,07 (p=0,011). Conclusões: Guarapuava apresentou importantes tendências de redução da gravidez precoce e aumento de escolaridade das mães, além de mudanças sobre as condições em que nascem seus filhos e sobre como são acolhidos.

Prediction of Preterm Delivery Using Serum Ischemia Modified Albumin, Biglycan, and Decorin Levels in Women with Threatened Preterm Labor / Previsão de parto prematuro usando albumina modificada por isquemia sérica, biglicano e níveis de decorina em mulheres com ameaça de trabalho de parto prematuro

Abstract Objective The serum ischemia modified albumin (IMA), biglycan, and decorin levels of pregnant women who were hospitalized for threatened preterm labor were measured. Methods Fifty-one consecutive pregnant women with a single pregnancy between the 24th and 36th weeks with a diagnosis of threatened preterm labor were included in the present prospective cohort study. Results As a result of multivariate logistic regression analysis for predicting preterm delivery within 24 hours, 48 hours, 7 days, 14 days, ≤ 35 gestational weeks, and ≤ 37 gestational weeks after admission, area under the curve (AUC) (95% confidence interval [CI[) values were 0.95 (0.89-1.00), 0.93 (0.86-0.99), 0.91 (0.83-0.98), 0.92 (0.85-0.99), 0.82 (0.69-0.96), and 0.89 (0.80-0.98), respectively. In the present study, IMA and biglycan levels were found to be higher and decorin levels lower in women admitted to the hospital with threatened preterm labor and who gave preterm birth within 48 hours compared with those who gave birth after 48 hours. Conclusion In pregnant women admitted to the hospital with threatened preterm labor, the prediction preterm delivery of the combined model created by adding IMA, decorin, and biglycan in addition to the TVS CL measurement was higher than the TVS CL measurement alone. Clinical trial registration The present trial was registered at ClinicalTrials.gov, number NCT04451928.

Resumo Objetivo Medir os níveis séricos de albumina modificada por isquemia (IMA), biglicano e decorina de gestantes hospitalizadas por ameaça de parto prematuro. Métodos Cinquenta e uma mulheres grávidas consecutivas com uma única gravidez entre a 24ᵃ e a 36ᵃ semanas com diagnóstico de ameaça de trabalho de parto prematuro foram incluídas no presente estudo de corte prospectivo. Resultados Como resultado da análise de regressão logística multivariada para prever parto prematuro dentro de 24 horas, 48 horas, 7 dias, 14 dias, ≤ 35 semanas gestacionais e ≤ 37 semanas gestacionais após a admissão, área sob a curva (AUC) (95% de confiança os valores de intervalo [CI[) foram 0,95 (0,89-1,00), 0,93 (0,86-0,99), 0,91 (0,83-0,98), 0,92 (0,85-0,99), 0,82 (0,69-0,96) e 0,89 (0,80-0,98), respectivamente. No presente estudo, os níveis de IMA e biglican foram maiores e os níveis de decorin menores em mulheres admitidas no hospital com ameaça de trabalho de parto prematuro e que tiveram parto prematuro em 48 horas em comparação com aquelas que deram à luz após 48 horas. Conclusão Em gestantes admitidas no hospital com ameaça de trabalho de parto prematuro, a predição de parto prematuro do modelo combinado criado pela adição de IMA, decorin e biglican, além da medição do TVS CL, foi maior do que a medição do TVS CL isoladamente. Registro do ensaio clínico O presente ensaio foi registrado em ClinicalTrials.gov, número NCT04451928.

Prediction of Preterm Delivery Using Serum Ischemia Modified Albumin, Biglycan, and Decorin Levels in Women with Threatened Preterm Labor.

OBJECTIVE: The serum ischemia modified albumin (IMA), biglycan, and decorin levels of pregnant women who were hospitalized for threatened preterm labor were measured. METHODS: Fifty-one consecutive pregnant women with a single pregnancy between the 24th and 36th weeks with a diagnosis of threatened preterm labor were included in the present prospective cohort study. RESULTS: As a result of multivariate logistic regression analysis for predicting preterm delivery within 24 hours, 48 hours, 7 days, 14 days, ≤ 35 gestational weeks, and ≤ 37 gestational weeks after admission, area under the curve (AUC) (95% confidence interval [CI[) values were 0.95 (0.89-1.00), 0.93 (0.86-0.99), 0.91 (0.83-0.98), 0.92 (0.85-0.99), 0.82 (0.69-0.96), and 0.89 (0.80-0.98), respectively. In the present study, IMA and biglycan levels were found to be higher and decorin levels lower in women admitted to the hospital with threatened preterm labor and who gave preterm birth within 48 hours compared with those who gave birth after 48 hours. CONCLUSION: In pregnant women admitted to the hospital with threatened preterm labor, the prediction preterm delivery of the combined model created by adding IMA, decorin, and biglycan in addition to the TVS CL measurement was higher than the TVS CL measurement alone. CLINICAL TRIAL REGISTRATION: The present trial was registered at ClinicalTrials.gov, number NCT04451928.

OBJETIVO: Medir os níveis séricos de albumina modificada por isquemia (IMA), biglicano e decorina de gestantes hospitalizadas por ameaça de parto prematuro. MéTODOS: Cinquenta e uma mulheres grávidas consecutivas com uma única gravidez entre a 24ª e a 36ª semanas com diagnóstico de ameaça de trabalho de parto prematuro foram incluídas no presente estudo de corte prospectivo. RESULTADOS: Como resultado da análise de regressão logística multivariada para prever parto prematuro dentro de 24 horas, 48 horas, 7 dias, 14 dias, ≤ 35 semanas gestacionais e ≤ 37 semanas gestacionais após a admissão, área sob a curva (AUC) (95% de confiança os valores de intervalo [CI[) foram 0,95 (0,89­1,00), 0,93 (0,86­0,99), 0,91 (0,83­0,98), 0,92 (0,85­0,99), 0,82 (0,69­0,96) e 0,89 (0,80­0,98), respectivamente. No presente estudo, os níveis de IMA e biglican foram maiores e os níveis de decorin menores em mulheres admitidas no hospital com ameaça de trabalho de parto prematuro e que tiveram parto prematuro em 48 horas em comparação com aquelas que deram à luz após 48 horas. CONCLUSãO: Em gestantes admitidas no hospital com ameaça de trabalho de parto prematuro, a predição de parto prematuro do modelo combinado criado pela adição de IMA, decorin e biglican, além da medição do TVS CL, foi maior do que a medição do TVS CL isoladamente. REGISTRO DO ENSAIO CLíNICO: O presente ensaio foi registrado em ClinicalTrials.gov, número NCT04451928.

Prevalência e desfechos materno-fetais de pacientes internadas por amniorrexe prematura no pré-termo no Hospital Universitário da Faculdade de Medicina de Jundiaí nos anos de 2020 e 2021 / Prevalence and maternal-fetal outcomes in patients hospitalized with preterm premature rupture of membranes at the University Hospital of Jundiaí's Medical School in the years 2020 and 2021

Objetivo: Atualizar a estatística do serviço, reconhecendo a prevalência de amnior- rexe prematura no pré-termo e seus principais desfechos materno-fetais. Méto- dos: Estudo transversal realizado pela análise de prontuários médicos de pacien- tes internadas devido a amniorrexe prematura no pré-termo e de seus respectivos conceptos no Hospital Universitário da Faculdade de Medicina de Jundiaí durante o período de janeiro de 2020 a dezembro de 2021. Resultados: Participaram da pesquisa 161 pacientes e 166 conceptos, resultando em uma prevalência de 2,12% no período estudado, com intervalo de confiança de 95% (1,80-2,47). Entre os des- fechos maternos, 2,5% das gestantes compunham critérios para near miss mater- no; enquanto entre os desfechos fetais, o resultado foi de 54,8% dos conceptos apresentando complicações, sendo as mais prevalentes a síndrome do desconfor- to respiratório (36,3%), icterícia (39,5%), baixo peso (27,5%) e hipoglicemia (24,2%). Além disso, 40,4% necessitaram de internação na unidade de terapia intensiva, 22,9% foram classificados como near miss neonatal e 4,4% foram a óbito. Conclu- são: Os resultados seguiram os padrões nacionais e internacionais esperados para prevalência de amniorrexe prematura no pré-termo e seus desfechos materno-fe- tais, com alta porcentagem de internações e complicações neonatais e baixa taxa de complicações maternas.

Objective: To update service statistics, recognizing the preva- lence of the pathology and its main outcomes. Methods: Cros- s-sectional study carried out through the analysis of medical records of patients hospitalized due to preterm premature rup- ture of membranes and their respective fetuses at the Univer- sity Hospital of Jundiaí's Medical School during the period from January 2020 to December 2021. Results: A total of 161 patients and 166 fetuses participated in the research, resulting in a pre- valence of 2.12% in the period studied with 95% confidence in- terval (1.80-2.47). About the outcomes, 2.5% of the pregnant wo- men composed the criteria for maternal near miss; as for the fetus, complications evolved in 54.8% of the fetuses, the most prevalent being respiratory distress syndrome (36.3%), jaundice (39.5%), low birth weight (27.5%) and hypoglycemia (24.2%). In addition, 40.4% required admission to the intensive care unit, 22.9% were neonatal near miss and 4.4% died. Conclusion: The results followed the expected national and international standards for the prevalence of preterm premature rupture of membranes and its maternal and fetal outcomes, with a high percentage of hospitalizations and neonatal complications, and a low rate of maternal complications.

Progressive multiple organ dysfunction syndrome in adolescent pregnancy: Case report. / Síndrome de disfunción orgánica múltiple progresiva en embarazo adolescente: reporte de caso clínico.

Introduction: Adolescent pregnancy is a physiological process, but it can evolve with premature delivery, severe obstetric or clinical pathologies, mortality, or sequelae for mother and child. We aim to report the progressive multiple organ dysfunction syndrome secondary to pyelonephritis and sepsis during prepartum, delivery, and puerperium of adolescent pregnancy and its sequelae. Case report: A 14-year-old adolescent with a pregnancy of 27 weeks of gestation controlled from 8 to 25 weeks. She was urgently admitted to the high-risk obstetric unit due to signs of preterm labor, pyelonephritis, and acute renal injury. Treatment was started with intravenous cefazolin and betamethasone for lung maturation, oral nifedipine, and magnesium sulfate to prevent preterm labor and fetal neuronal protection, evolving with sustained hypotension and septic shock. At 13 hours after admission, she was transferred to the intensive care unit, where she evolved with persistent and progressive multiple organ failure for 28 days, progressively affecting the cardiovascular, hematologic, respiratory, and gastrointestinal systems. She was treated with vasoactive drugs, antibiotics, invasive mechanical ventilation, ultrafiltration, hemodialysis, pleural drainage, and cholecystectomy. Twenty-four hours after admission to intensive care, preterm vaginal delivery occurred. She developed chronic kidney disease stage KDIGO 5 (Kidney Disease Improving Global Outcomes V) and is awaiting renal transplantation. On the other hand, the preterm newborn presented severe neonatal asphyxia, bronchopulmonary dysplasia, and hypoxic-ischemic encephalopathy. Conclusion: Complicated adolescent pregnancy is a health emergency. Avoiding delays in the diagnosis and treatment of pyelonephritis, septic shock and the progressive multiple organ dysfunction syndrome can prevent mortality and permanent sequelae, both maternal and neonatal.

Introducción: El embarazo adolescente es un proceso fisiológico, pero puede evolucionar con parto prematuro, patologías obstétricas o médicas graves, mortalidad o secuelas para madre e hijo/a. Nuestro objetivo es reportar el síndrome de disfunción orgánica múltiple progresiva secundario a pielonefritis y sepsis ocurrido durante el preparto, parto y puerperio de embarazo adolescente y sus secuelas. Caso clínico: Adolescente de 14 años, con embarazo de 27 semanas de gestación controlado desde las 8 hasta 25 semanas. Ingresó de urgencia en unidad de alto riesgo obstétrico por signos de parto prematuro, pielonefritis e injuria renal aguda. Se inició tratamiento con cefazolina intravenosa y betametasona para maduración pulmonar, nifedipino oral y sulfato de magnesio para prevención del parto prematuro y protección neuronal fetal, evolucionando con hipotensión sostenida y shock séptico. A las 13 horas después del ingreso, fue trasladada a unidad de paciente crítico donde evolucionó con falla orgánica múltiple persistente y progresiva durante 28 días, afectando sucesivamente los sistemas cardiovascular, hematológico, respiratorio y gastrointestinal. Se trató con drogas vasoactivas, antibióticos, ventilación mecánica invasiva, ultrafiltración, hemodiálisis, drenaje pleural y colecistectomía. A las 24 horas de ingreso a cuidado intensivo, ocurrió el parto prematuro vaginal. La embarazada desarrolló enfermedad renal crónica etapa KDIGO 5 ( V) y se encuentra en espera de trasplante renal. Por su parte, la recién nacida prematura viva presentó asfixia neonatal severa, displasia broncopulmonar y encefalopatía hipóxico-isquémica.El embarazo adolescente complicado es una emergencia sanitaria. El diagnóstico y manejo oportuno de la pielonefritis, shock séptico y disfunción orgánica asociada a la sepsis pueden evitar mortalidad y secuelas permanentes materna y/o neonatal.

Síndrome de disfunción orgánica múltiple progresiva en embarazo adolescente: reporte de caso clínico / Progressive multiple organ dysfunction syndrome in adolescent pregnancy: case report

INTRODUCCIÓN: El embarazo adolescente es un proceso fisiológico, pero puede evolucionar con parto prematuro, patologías obstétricas o médicas graves, mortalidad o secuelas para madre e hijo/a. Nuestro objetivo es reportar el síndrome de disfunción orgánica múltiple progresiva secundario a pielonefritis y sepsis ocurrido durante el preparto, parto y puerperio de embarazo adolescente y sus secuelas. CASO CLÍNIO: Adolescente de 14 años, con embarazo de 27 semanas de gestación controlado desde las 8 hasta 25 semanas. Ingresó de urgencia en unidad de alto riesgo obstétrico por signos de parto prematuro, pielonefritis e injuria renal aguda. Se inició tratamiento con cefazolina intravenosa y betametasona para maduración pulmonar, nifedipino oral y sulfato de magnesio para prevención del parto prematuro y protección neuronal fetal, evolucionando con hipotensión sostenida y shock séptico. A las 13 horas después del ingreso, fue trasladada a unidad de paciente crítico donde evolucionó con falla orgánica múltiple persistente y progresiva durante 28 días, afectando sucesivamente los sistemas cardiovascular, hematológico, respiratorio y gastrointestinal. Se trató con drogas vasoactivas, antibióticos, ventilación mecánica invasiva, ultrafiltración, hemodiálisis, drenaje pleural y colecistectomía. A las 24 horas de ingreso a cuidado intensivo, ocurrió el parto prematuro vaginal. La embarazada desarrolló enfermedad renal crónica etapa KDIGO 5 ( V) y se encuentra en espera de trasplante renal. Por su parte, la recién nacida prematura viva presentó asfixia neonatal severa, displasia broncopulmonar y encefalopatía hipóxico-isquémica. CONCLUSIONES: El embarazo adolescente complicado es una emergencia sanitaria. El diagnóstico y manejo oportuno de la pielonefritis, shock séptico y disfunción orgánica asociada a la sepsis pueden evitar mortalidad y secuelas permanentes materna y/o neonatal.

INTRODUCTION: Adolescent pregnancy is a physiological process, but it can evolve with premature delivery, severe obstetric or clinical pathologies, mortality, or sequelae for mother and child. We aim to report the progressive multiple organ dysfunction syndrome secondary to pyelonephritis and sepsis during prepartum, delivery, and puerperium of adolescent pregnancy and its sequelae. CASE REPORT: A 14-year-old adolescent with a pregnancy of 27 weeks of gestation controlled from 8 to 25 weeks. She was urgently admitted to the high-risk obstetric unit due to signs of preterm labor, pyelonephritis, and acute renal injury. Treatment was started with intravenous cefazolin and betamethasone for lung maturation, oral nifedipine, and magnesium sulfate to prevent preterm labor and fetal neuronal protection, evolving with sustained hypotension and septic shock. At 13 hours after admission, she was transferred to the intensive care unit, where she evolved with persistent and progressive multiple organ failure for 28 days, progressively affecting the cardiovascular, hematologic, respiratory, and gastrointestinal systems. She was treated with vasoactive drugs, antibiotics, invasive mechanical ventilation, ultrafiltration, hemodialysis, pleural drainage, and cholecystectomy. Twenty-four hours after admission to intensive care, preterm vaginal delivery occurred. She developed chronic kidney disease stage KDIGO 5 (Kidney Disease Improving Global Outcomes V) and is awaiting renal transplantation. On the other hand, the preterm newborn presented severe neonatal asphyxia, bronchopulmonary dysplasia, and hypoxic-ischemic encephalopathy. CONCLUSION: Complicated adolescent pregnancy is a health emergency. Avoiding delays in the diagnosis and treatment of pyelonephritis, septic shock and the progressive multiple organ dysfunction syndrome can prevent mortality and permanent sequelae, both maternal and neonatal.

Sociodemographic determinants and mortality of premature newborns in a medium and low-income population in Colombia, 2017-2019 / Factores determinantes sociodemográficos y de mortalidad en recién nacidos prematuros en población de medianos y bajos ingresos en Colombia, 2017-2019

Introduction. The birth of premature babies is a public health problem with a high impact on infant morbidity and mortality. About 40% of mortality in children under five years occurs in the first month of life. Objective. To identify the association between maternal sociodemographic factors, premature birth, and mortality in newborns under 37 weeks in Santiago de Cali, 2017-2019. Materials and methods. We conducted a descriptive, cross-sectional study. We evaluated the records of Cali's Municipal Public Health Office. We calculated the crude and adjusted odd ratios and confidence intervals (95%) using the logistic regression model, data processing in Stata 16, and georeferencing the cases in the QGIS software. Results. From 2017 to 2019, premature babies in Cali corresponded to 11% of births. Poor prenatal care increased 3.13 times the risk of being born before 32 weeks (adjusted OR = 3.13; 95% CI = 2.75 - 3.56) and 1.27 times among mothers from outside the city (adjusted OR = 1.27; 95% CI = 1.15-1.41). Mortality was 4.29 per 1,000 live births. The mortality risk in newborns weighing less than 1,000 g increased 3.42 times (OR = 3.42; 95% CI = 2.85-4.12), delivery by cesarean section in 1.46 (OR = 1.46; CI 95% = 1.14-1.87) and an Apgar score - five minutes after birth- lower than seven in 1.55 times (OR = 1.55; CI 95% = 1.23-1.96). Conclusions. We found that less than three prenatal controls, mothers living outside Cali, afro-ethnicity, and cesarean birth were associated with prematurity of less than 32 weeks. We obtained higher mortality in newborns weighing less than 1,000 g.

Introducción. El nacimiento de bebés prematuros es un problema de salud pública con gran impacto en la morbimortalidad infantil: cerca del 40 % de las muertes de niños menores de cinco años sucede en el primer mes de vida. Objetivo. Identificar la asociación entre los factores sociodemográficos maternos, el parto prematuro y la mortalidad en recién nacidos menores de 37 semanas en Santiago de Cali, 2017-2019. Materiales y métodos. Se hizo un estudio descriptivo transversal. Se evaluaron los registros de la Secretaría de Salud Pública Municipal de Cali. Se calcularon las razones de probabilidad y los intervalos de confianza (95 %) crudos y ajustados mediante el modelo de regresión logística, en tanto que los datos se procesaron en Stata 16 y los casos se georreferenciaron con el programa QGIS. Resultados. Entre el 2017 y el 2019, los nacimientos de bebés prematuros en Cali correspondieron al 11 %. El control prenatal deficiente aumentó 3,13 veces el riesgo de nacer con menos de 32 semanas (OR ajustado = 3,13; IC95% = 2,75-3,56) y, en madres de municipios fuera de la ciudad, 1,27 veces (OR ajustado = 1,27; IC95% = 1,15-1,41). La mortalidad fue de 4,29 por 1.000 nacidos vivos. Nacer con un peso menor de 1.000 g aumentó el riesgo de mortalidad en 3,42 veces (OR = 3,42; IC95% = 2,85-4,12) y, un puntaje Apgar menor de siete a los cinco minutos del nacimiento, en 1,55 veces (OR=1,55; IC95% = 1,23-1,96). Conclusiones. Se encontró que tener menos de tres controles prenatales, la procedencia de la madre fuera de Cali, ser afrodescendiente y el parto por cesárea, estaban asociados significativamente con la prematuridad de menos de 32 semanas. Hubo mayor mortalidad en los recién nacidos con menos de 1.000 gramos al nacer.

Vitamina D y embarazo: una experiencia piloto / Vitamin D and pregnancy: a pilot experience

La insuficiencia de vitamina D (VD) en el embarazo se relaciona con una mayor incidencia de cesáreas, preeclampsia y partos prematuros. Objetivo: evaluar si el grado de insuficiencia de VD se asocia a mayor número de cesáreas y evaluar la correlación entre la 25 hidroxivitamina D (25OHD) materna y en sangre del cordón del recién nacido. Las mujeres (n=127) se dividieron según sus niveles de 25OHD (ng/mL):G1:<20 (deficiencia), G2:20-30 (insuficiencia), G3:>30 (suficiencia). Se registraron edad; edad gestacional (EG); índice de masa corporal (IMC); tensión arterial sistólica y diastólica; tipo de parto y la estación del año en que se tomó la muestra. Se determinaron calcemia (ng/mL); 25OHD; parathormona intacta (pg/mL); fosfatasa alcalina ósea (UI/L) y crosslaps (pg/mL). La edad media fue de 26±6 años y la EG de 35,8±2,7 semanas, sin diferencias entre grupos. El porcentaje de cesáreas fue mayor en G1 que en G2 y G3 (31,3%, 21,4% y 25%, respectivamente; p<0,05). El mayor porcentaje de muestras se tomó en primavera (p<0,05). No se observaron diferencias en las demás variables maternas estudiadas. La 25OHD materna correlacionó positivamente con los valores de la sangre de cordón de sus respectivos recién nacidos (r= 0,67; p<0,0001). Independientemente de la época del año y del IMC, se observó que un porcentaje significativo de las mujeres embarazadas estudiadas tenía niveles de 25OHD inferiores a 30 ng/mL. Conclusión: evidenciamos que la deficiencia de VD materna se asoció al número de cesáreas. Asimismo, los niveles séricos de 25OHD en sangre de cordón umbilical correlacionaron significativamente con los maternos. (AU)

Vitamin D (VD) insufficiency in pregnancy is associated with a higher incidence of cesarean section, preeclampsia, and preterm delivery. Objective: to evaluate if the degree of VD insufficiency is associated with the incidence of cesarean section and to determine the correlation between maternal and newborn cord blood 25-hydroxy VS (25OHD). Women (n=127) were divided according to their 25OHD levels (ng/mL): G1:<20 (deficiency), G2:20-30 (insufficiency), G3:>30 (sufficiency). Age; gestational age (GA); body mass index (BMI); systolic and diastolic blood pressure (mmHg); type of delivery and the season of the year in which the sample was taken were recorded. Calcemia (ng/mL); 25OHD; intact parathormone (pg/mL); bone alkaline phosphatase (IU/L) and Crosslaps (pg/mL) levels were determined. Mean age was 26±6 years and GA was 35.8±2.7 weeks with no differences among groups. The % of cesarean sections was higher in G1 than in G2 and G3 (31.3%, 21.4% and 25%; p<0.05). The highest % of samples were taken in spring (p<0.05). No differences were observed in the other maternal variables studied. Maternal serum 25OHD levels correlated positively with those of cord blood from their respective newborns (r=0.67; p<0.0001). Regardless the season of the year and BMI, a high % of the studied pregnant women presented 25OHD levels lower than 30 ng/ml. Conclusion: we found that maternal VD deficiency is associated with the number of cesarean sections. In addition, 25OHD levels in the newborn significantly correlate with maternal serum levels. (AU)

Ruptura prematura de membranas ovulares / Premature rupture of ovular membranes

La ruptura prematura de las membranas ovulares se define como la pérdida de la integridad del amnios y corion antes del inicio del trabajo de parto, afecta el 3 % de los embarazos, causa un tercio de los partos pretérminos, los cuales ocupan el 10,49 % de los nacimientos y es el origen de altos índices de morbimortalidad perinatal. En la actualidad, el manejo de esta patología se orienta principalmente en evitar los factores de riesgo, hacer un diagnóstico adecuado, determinar la edad gestacional en que ocurre, realizar el monitoreo exhaustivo del bienestar materno-fetal y en decidir el momento idóneo de finalización de la gestación para minimizar sus complicaciones. Debido a la compleja y lábil estructura histológica de las membranas ovulares, se ha dejado a un lado el tratamiento directo de la entidad el cual sería sellar o reparar el defecto en sí. En los últimos años, numerosos estudios y protocolos clínicos de prestigiosos centros asistenciales han servido como guía para el manejo de esta entidad, pero en muy pocos se observa una terapia destinada a la reparación de dichas membranas o en sellar tal defecto. Las evidencias científicas demuestran que la regeneración y reparación de las membranas es lenta y compleja y los tratamientos propuestos para reparar o sellar su defecto no han gozado de la aceptación científica para su aprobación, sin embargo, el uso del parche hemático transvaginal endocervical autólogo luce como una alternativa terapéutica prometedora(AU)

The premature rupture of the ovular membranes is defined as the loss of the integrity of the amnion and chorion before the on set of labor, affects 3% of pregnancies, causes athird of preterm births which occupy 10,49% of births and is the origin of high rates of perinatal morbidity and mortality. At present, the management of this pathology is mainly oriented towards avoiding risk factors, making an adequate diagnosis, determining the gestational age in which it occurs, carrying out exhaustive monitoring of maternal-fetal well-being and deciding the ideal moment to end the treatment. Pregnancy to minimizeits complications. Due to the complex and labile histological structure of the ovular membranes, the direct treatment of the entity has been set a side, which would be to seal or repairthe defect it self. In recent years, numerous studies and clinicalprotocols from prestigious health care centers have served as aguide for the management of this entity, but very few have observed a therapy aimed at repairing said membranes or sealing such a defect. Scientific evidence shows that the regeneration and repair of the membranes is slow and complex and the treatment sproposed to repair or seal their defect have not enjoyed scientific acceptance for their approval, how ever, the use of the autologous endocervical transvaginal blood patch looks like a promising therapeutic alternative(AU)

Exposición antenatal a contaminantes vehiculares y asociación con parto pretérmino en Colombia / Antenatal exposure to vehicular pollutants and association with preterm birth in Colombia

Objetivo: Determinar la asociación entre parto pretérmino y exposición prenatal de gestantes a emisiones vehiculares de material particulado menor de 10 micras y de monóxido de carbono, en una ciudad de Colombia, entre julio de 2014 y julio de 2015. Métodos: Estudio relacional, retrospectivo, de casos y controles, en el Hospital de Caldas de la ciudad de Manizales; en mujeres que asistieron para atención del parto. La exposición a emisiones vehiculares de material particulado menor de 10 micras y de monóxido de carbono, se determinó usando estimaciones previamente publicadas para la ciudad. El análisis estadístico se realizó en el aplicativo Jamovi ­ Stats Open Now. Se contó con el aval de los comités de ética de las instituciones implicadas. Resultados: Se analizaron 222 pacientes, 74 presentaron parto pretérmino (casos) y 148 parto a término (controles). No se encontró asociación estadísticamente significativa entre el desarrollo de parto pretérmino y los niveles de material particulado menor de 10 micras o de monóxido de carbono; no obstante, podría haber una asociación entre parto pretérmino y aseguramiento en salud, que no pudo establecerse por el tamaño de muestra pequeño. También se obtuvo el patrón espacial de los casos de parto pretérmino en la ciudad con base en la residencia habitual de las pacientes. Conclusión: Los contaminantes ambientales como el material particulado menor de 10 micras y el monóxido de carbono, pueden estar implicados en la presentación de parto pretérmino, sin embargo, se requieren más estudios que analicen esta asociación(AU)

Objective: To determine the association between preterm delivery and prenatal exposure of pregnant women to vehicular emissions of particulate matter smaller than 10 microns and carbon monoxide, in a city in Colombia, between July 2014 and July 2015. Methods: Relational, retrospective, case-control study at the Caldas Hospital in the city of Manizales; in women who attended delivery care. Exposure to vehicular emissions of particulate matter smaller than 10 microns and carbon monoxide was determined using previously published estimates for the city. The statistical analysis was carried out in the Jamovi ­ Stats Open Now application. It had the endorsement of the ethics committees of the institutions involved. Results: A total of 222 patients were analyzed, 74 presented preterm delivery (cases) and 148 term delivery (controls). No statistically significant association was found between the development of preterm labor and levels of particulate matter less than 10 microns or carbon monoxide; however, there could be an association between preterm delivery and health insurance, which could not be established due to the small sample size. The spatial pattern of cases of preterm delivery in the city was also obtained based on the habitual residence of the patients. Conclusion: Environmental pollutants such as particulate matter smaller than 10 microns and carbon monoxide may be involved in the presentation of preterm labor, however, more studies are required to analyze this association(AU)

Circulating Extracellular Vesicles microRNAs Are Altered in Women Undergoing Preterm Birth.

Preterm labor (PTL) and preterm premature rupture of membranes (PPROM) lead to high perinatal morbidity/mortality rates worldwide. Small extracellular vesicles (sEV) act in cell communication and contain microRNAs that may contribute to the pathogenesis of these complications. We aimed to compare the expression, in sEV from peripheral blood, of miRNAs between term and preterm pregnancies. This cross-sectional study included women who underwent PTL, PPROM, and term pregnancies, examined at the Botucatu Medical School Hospital, SP, Brazil. sEV were isolated from plasma. Western blot used to detect exosomal protein CD63 and nanoparticle tracking analysis were performed. The expression of 800 miRNAs was assessed by the nCounter Humanv3 miRNA Assay (NanoString). The miRNA expression and relative risk were determined. Samples from 31 women-15 preterm and 16 term-were included. miR-612 expression was increased in the preterm groups. miR-612 has been shown to increase apoptosis in tumor cells and to regulate the nuclear factor κB inflammatory pathway, processes involved in PTL/PPROM pathogenesis. miR-1253, miR-1283, miR378e, and miR-579-3p, all associated with cellular senescence, were downregulated in PPROM compared with term pregnancies. We conclude that miRNAs from circulating sEV are differentially expressed between term and preterm pregnancies and modulate genes in pathways that are relevant to PTL/PPROM pathogenesis.

Perfusão arterial reversa gemelar: revisão da literatura / Twin reverse arterial perfusion: literature review

A perfusão arterial reversa gemelar é uma anormalidade rara que pode ocorrer em gestações gemelares monocoriônicas. Consiste em uma alteração na circulação fetoplacentária, com desvio de sangue de um dos gemelares para o outro, por meio de anastomoses arterioarteriais e venovenosas na superfície placentária e anastomoses arteriovenosas em áreas de circulação placentária compartilhada. O feto bombeador pode desenvolver insuficiência cardíaca devido ao aumento do débito cardíaco, e o feto receptor, perfundido por sangue pobre em oxigênio por meio do fluxo reverso, é severamente malformado, incompatível com a vida extrauterina. Este artigo apresenta o caso de uma gestação gemelar monocoriônica diamniótica, com manejo clínico conservador. O objetivo é relatar um caso de complicação rara de gestações monozigóticas e revisar condutas para diagnóstico e manejo adequado.(AU)

Twin reverse arterial perfusion is a rare abnormality that can occur in monochorionic twin pregnancies. It consists of an alteration in the fetal-placental circulation, with blood diversion from one of the twins to the other, through arterio-arterial and veno- venous anastomosis on the placental surface and arterio-venous anastomosis in areas of shared placental circulation. The pumping fetus may develop heart failure due to increased cardiac output, and the recipient fetus, perfused by oxygen-poor blood through reverse flow, is severely malformed, incompatible with extrauterine life. This article presents the case of a monochorionic diamniotic twin pregnancy, with conservative clinical management. The objective is to report a case of rare complication of monozygotic pregnancies and review procedures for diagnosis and adequate management.(AU)

Cervicovaginal Cytokines to Predict the Onset of Normal and Preterm Labor: a Pseudo-longitudinal Study.

Inflammatory processes associated with human parturition are still not completely understood, not only because the gap between inflammation and the onset of labor has been difficult to study but also because of the limited knowledge about the role of cervicovaginal fluid (CVF) cytokines during the sequence of labor. We aimed to determine whether CVF cytokines could predict the onset of normal and preterm labor. Chemokines and proinflammatory and anti-inflammatory cytokines in CVF were measured in a pseudo-longitudinal manner in healthy women between 12 and 41 weeks gestation with intact fetal membranes before and during the first stage of labor. Women were grouped into five stages, from the absence of uterine activity and cervical changes to regular uterine contractions with cervix dilation > 3 cm (active phase of labor). Of 144 women with spontaneous labor, 96 gave birth at term, 48 gave birth preterm, and both groups displayed similar cytokine concentrations. We found positive correlations between proinflammatory cytokines and the initial sequence of labor, using individual cytokines and score-based data by principal component analysis (IFN-γ, TNF-α, IL-1ß, IL-6) as dependent variables. The risk of labor onset increased as the concentrations of IL-6 increased (hazard ratio = 202.09, 95% confidence interval = 24.57-1662.49, P < 0.001). The IL-6 concentration predicted the onset of labor within 12 days of sampling (area under the time-dependent ROC curve = 0.785, 95% confidence interval = 0.693-0.877). Here, we showed that regardless of gestational age, the onset of labor could be predicted by the IL-6 concentration in the CVF, since the initial sequence of spontaneous labor displayed an inflammatory response expressed by the increase in proinflammatory cytokines.

Estimates of avoided costs attributed to a short cervix screening program to prevent preterm birth from the perspective of the Unified Health System (SUS) / Estimativa de custos evitados atribuídos a um programa de rastreio de colo curto para prevenção da prematuridade na perspectiva do SUS

ABSTRACT OBJECTIVE To perform an economic cost analysis of the implementation of a short cervix screening program to reduce preterm birth in singleton pregnancies in a short-term time horizon. METHODS We performed a cost-benefit economic analysis using the P5 trial database, a randomized multicenter clinical trial for prevention of preterm birth. Data collection was conducted from July 2015 to March 2019 in 17 different Brazilian hospitals. We conducted a cost analysis for universal cervical screening in singleton pregnancies between 18 weeks and 22 weeks plus 6 days. In subjects with a cervical length ≤ 25 mm, the analysis incorporated the costs of administering 200 mg/day of vaginal progesterone prophylactically until 36 weeks gestation. These findings were subsequently compared with the economic implications of forgoing cervical screening. The time horizon comprised from birth to 10 weeks postpartum. The outcome was measured monetarily in Brazilian real (R$) from the perspective of the Unified Health System. RESULTS Among 7,844 women, 6.67% (523) had a cervix ≤ 25 mm. The cost of screening with transvaginal ultrasound and vaginal progesterone for prevention of births with < 34 weeks was estimated at R$ 383,711.36, while non-screening generated an estimated additional cost of R$ 446,501.69 (related to the 29 non-screened preterm deliveries). Thus, screening and prophylaxis would generate a final cost reduction of R$ 62,790.33, constituting a possible cost-benefit strategy. CONCLUSION Universal short cervix screening for preterm birth has lower costs compared to non-screening within a short-term time horizon, which suggests an interesting benefit-cost ratio. Future studies should consider the cost-effectiveness of prophylactic treatment using sensitivity analyses in different scenarios within the Brazilian health system, as well as analyses that consider the long-term costs associated with preterm births, to robustly justify the implementation of a short cervix screening program.

RESUMO OBJETIVO Realizar uma análise econômica de custo da implementação de um programa de rastreio de colo curto para redução da prematuridade em gestações únicas num horizonte temporal de curto prazo. MÉTODOS Realizamos uma análise econômica do tipo custo-benefício utilizando o banco de dados do P5 trial, um ensaio clínico multicêntrico randomizado para prevenção da prematuridade. A coleta de dados ocorreu de julho de 2015 a março de 2019 em 17 diferentes hospitais do Brasil. Comparamos os custos do rastreamento universal em mulheres com gestação única de 18 a 22 semanas e 6 dias associado à progesterona vaginal profilática 200 mg/dia até 36 semanas naquelas com colo ≤ 25 mm com os do não rastreamento. O horizonte temporal foi do nascimento até 10 semanas após o parto. O desfecho foi medido monetariamente em real brasileiro (R$) na perspectiva do Sistema Único de Saúde. RESULTADOS Entre 7.844 mulheres, 6,67% (523) apresentaram colo ≤ 25mm. O custo do rastreio com a ultrassonografia transvaginal mais a progesterona vaginal para prevenção de nascimentos < 34 semanas foi estimado em R$ 383.711,36, enquanto o não rastreamento gerou custo adicional estimado de R$ 446.501,69 (relacionado aos 29 partos prematuros não rastreados). Assim, o rastreamento mais a profilaxia geraria uma redução de custo final de R$ 62.790,33, apresentando-se como uma possível estratégia de custo-benefício. CONCLUSÃO O rastreamento universal de colo curto para prematuridade apresenta menores custos em relação ao não rastreamento dentro de um horizonte temporal de curto prazo, o que sugere uma interessante relação de custo versus benefício. Novos estudos que considerem a custo-efetividade do tratamento profilático utilizando-se de análises de sensibilidade em diferentes cenários dentro do sistema de saúde brasileiro, assim como análises que considerem os custos de longo prazo atrelados ao nascimento prematuro, são necessários para justificar com robustez a implementação de um programa de rastreamento.

Prevalência e tendência temporal da prematuridade no Brasil antes e durante a pandemia de covid-19: análise da série histórica 2011-2021 / Prevalencia y tendencia temporal de la prematuridad en Brasil antes y durante la pandemia de COVID-19: análisis de la serie histórica de 2011 a 2021 / Prevalence and temporal trend of prematurity in Brazil before and during the COVID-19 pandemic: a historical time series analysis, 2011-2021

Objetivo: mensurar a prevalência de prematuridade segundo macrorregião brasileira e características maternas, nos últimos 11 anos; comparar as proporções durante a pandemia de covid-19 (2020-2021) com as da série histórica (2011-2019). Métodos: estudo ecológico, com dados do Sistema de Informações sobre Nascidos Vivos; prevalências calculadas segundo ano, macrorregião e características maternas; análise da série temporal pelo modelo de Prais-Winsten. Resultados: a prevalência de prematuridade em 2011-2021 foi de 11,1%, estável; a média no período pandêmico 11,3% (IC95% 11,2;11,4%) assemelhou-se à do período-base 11,0% (IC95% 10,6;11,5%); a região Norte (11,6%) apresentou a maior proporção entre 2011 e 2021; gestação gemelar (56,3%) e gestantes com 4-6 consultas de pré-natal (16,7%) apresentaram tendência crescente (p-valor < 0,001); observou-se maior prevalência para extremos de idade materna, gestantes de raça/cor da pele preta, indígenas e menor escolaridade. Conclusão: maior prematuridade nas gestantes socialmente vulneráveis, em gestações gemelares e no Norte; prevalência estável, sem diferença entre períodos.

Objetivo: medir la prevalência de prematuridad de 2011 a 2021, según macrorregión brasileña y características maternas, comparando los años de pandemia de COVID-19, con 2011-2019. Métodos: estudio ecológico basado en el Sistema de Información de Nacimientos Vivos. Prevalencias calculadas según año, macrorregión y características maternas. Análisis de series temporales por el modelo generalizado de Prais-Winsten. Resultados: la prematuridad entre 2011-2021 fue 11,1%, con estabilidade; la media de en el periodo de la pandemia 11,3% (IC95% 11,2;11,4) se asemejó a la media de referencia 11,0% (IC95% 10,6;11,5). Región del norte tuvo la proporción más alta entre 2011 y 2021. Embarazo gemelar y mujeres con 4-6 visitas prenatales tuvieron tendencia al aumento. Prevalencias más elevadas correspondían a la edad materna extrema, mujeres embarazadas negras e indígenas y niveles de educación más bajos. Conclusión: mayor prematuridad en situación de vulnerabilidad social, embarazos gemelares y de la Región Norte. Proporciones se mantuvieron estables, sin diferencias entre períodos.

Objective: to measure the prevalence of prematurity according to the Brazilian macro-regions and maternal characteristics over the past 11 years; to compare the proportions during the COVID-19 pandemic (2020-2021) with those of the historical series (2011-2019). Methods: this was an ecological study, with data from the Live Birth Information System; the prevalence was calculated according to year, macro-region and maternal characteristics; time series analysis was performed using Prais-Winsten regression model. Results: the prevalence of preterm birth in 2011-2021 was 11.1%, stable; the average in the pandemic period 11.3% (95%CI 11.2;11.4%) was similar to that of the base period 11.0% (95%CI 10.6;11.5%); the North region (11.6%) showed the highest proportion between 2011 and 2021; twin pregnancy (56.3%) and pregnant women who had 4-6 prenatal care visits (16.7%) showed an increasing trend (p-value < 0.001); the highest prevalence was observed for extremes of maternal age, pregnant women of Black race/skin color, indigenous women and those with lower level of education. Conclusion: preterm birth rates were highest for socially vulnerable pregnant women, twin pregnancies and in the North; stable prevalence, with no difference between periods.