Tocolysis among Women with Preterm Birth: Associated Factors and Outcomes from a Multicenter Study in Brazil

Abstract

Objective To evaluate the use of tocolysis in cases of preterm birth due to spontaneous preterm labor in a Brazilian sample.

Methods A sample of 1,491 women with preterm birth due to spontaneous preterm labor were assessed, considering treatment with tocolysis or expectant management, according to gestational age at birth (< 34 weeks and 34 to 36 + 6 weeks) and drugs prescribed. The study took place in 20 Brazilian hospitals from April 2011 to July 2012. Bivariate analyses were conducted to evaluate associations with sociodemographic and obstetric characteristics and odds ratios with their respective 95% confidence intervals were estimated for maternal and neonatal outcomes.

Results A total of 1,491 cases of preterm birth were considered. Tocolysis was performed in 342 cases (23%), 233 of which (68.1%) were delivered before 34 weeks. Within the expectant management group, 73% was late preterm and with more advanced labor at the time of admission. The most used drugs were calcium channel blockers (62.3%), followed by betamimetics (33%). Among the subjects in the tocolysis group, there were more neonatal and maternal complications (majority non-severe) and an occurrence of corticosteroid use that was 29 higher than in the expectant management group.

Conclusion Tocolysis is favored in cases of earlier labor and also among those with less than 34 weeks of gestation, using preferably calcium channel blockers, with success in achieving increased corticosteroid use. Tocolysis, in general, was related to higher maternal and neonatal complication rates, which may be due to the baseline difference between cases at admission. However, these results should raise awareness to tocolysis use.

Resumo

Objetivo: Avaliar o uso da tocólise em partos prematuros decorrentes de trabalho de parto espontâneo numa amostra brasileira.

Métodos Um total de 1.491 mulheres com parto prematuro decorrente de trabalho de parto espontâneo foram avaliadas, considerando a realização de tocólise ou conduta expectante, de acordo com a idade gestacional ao nascimento (< 34 semanas e 34 a 36 + 6 semanas) e com as drogas prescritas. O estudo ocorreu em 20 hospitais brasileiros, de abril de 2011a julho de 2012. Análises bivariadas foram realizadas para avaliar associações com características sociodemográficas e obstétricas. Foram calculadas as relações de probabilidade com seus respectivos intervalos de confiança (95%) para os desfechos neonatais e maternos.

Resultados Um total de 1.491 casos de partos prematuros foram considerados, e a tocólise foi realizada em 342 (23%) casos, dos quais 233 (68,1%) tiveram partos antes das 34 semanas. No grupo da conduta expectante, 73% foram pré-termos tardios e com trabalho de parto mais avançado à admissão. As drogas mais utilizadas foram os bloqueadores do canal de cálcio (62.3%), seguidos pelos betamiméticos (33%). No grupo da tocólise houve mais complicações neonatais e maternas (maioria não grave) e um uso de corticosteroides 29 vezes mais frequente que nos casos de conduta expectante.

Conclusão A tocólise foi mais favorável nos casos de trabalho de parto inicial e nos partos realizados antes de 34 semanas de gestação, usando preferencialmente bloqueadores do canal de cálcio, com sucesso em realizar altas taxas de corticoterapia. A tocólise esteve associada a maiores taxas de complicações maternas e neonatais, o que pode ser explicado pela diferença basal dos casos à admissão. Entretanto, esses resultados devem acender um alerta em relação ao uso de tocolíticos.

Keywords

preterm birth - prematurity - preterm labor - tocolysis - neonatal outcomes - maternal outcomes

Palavras-chave

parto prematuro - prematuridade - trabalho de parto prematuro - tocólise - desfechos neonatais - desfechos maternos

Contributors

Dias T. Z., Fava M. L., Passini Júnior R., Cecatti J. G., Tedesco R. P., Lajos G. J., Rehder P. M., Nomura M. L., Oliveira P. F. and Costa M. L. contributed with the project and interpretation of data, writing of the article, critical review of the intellectual content and final approval of the version to be published.

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