Cesarean sections and early-term births according to Robson classification: a population-based study with more than 17 million births in Brazil

Abstract

Background Cesarean section (CS) rates are increasing worldwide and are associated with negative maternal and child health outcomes when performed without medical indication. However, there is still limited knowledge about the association between high CS rates and early-term births. This study explored the association between CSs and early-term births according to the Robson classification. Methods A population-based, cross-sectional study was performed with routine registration data of live births in Brazil between 2012 and 2019. We used the Robson classification system to compare groups with expected high and low CS rates. We used propensity scores to compare CSs to vaginal deliveries (1:1) and estimated associations with early-term births using logistic regression. Results A total of 17,081,685 live births were included. Births via CS had higher odds of early-term birth (OR 1.32; 95% CI 1.32–1.32) compared to vaginal deliveries. Births by CS to women in Group 2 (OR 1.50; 95% CI 1.49–1.51) and 4 (OR 1.57; 95% CI 1.56–1.58) showed the highest odds of early-term birth, compared to vaginal deliveries. Increased odds of an early-term birth were also observed among births by CS to women in Group 3 (OR 1.30, 95% CI 1.29–1.31), compared to vaginal deliveries. In addition, live births by CS to women with a previous CS (Group 5 - OR 1.36, 95% CI 1.35–1.37), a single breech pregnancy (Group 6 - OR 1.16; 95% CI 1.11–1.21, and Group 7 - OR 1.19; 95% CI 1.16–1.23), and multiple pregnancies (Group 8 - OR 1.46; 95% CI 1.40–1.52) had high odds of an early-term birth, compared to live births by vaginal delivery. Conclusions CSs were associated with increased odds of early-term births. The highest odds of early-term birth were observed among those births by CS in Robson Groups 2 and 4.

Optimizing caesarean section use and feasibility of implementing the Robson classification system: Perspectives of healthcare providers and policymakers

“…Despite its proven advantages, CS can lead to increased medical risks for both mothers and newborns, especially when performed without a medical indication. 1 – 3 …”

Trends in cesarean section rates in Brazil by Robson classification group, 2014-2020

“…Additionally, other Brazilian studies using the Robson Classification were localized ( 21 - 22 ) , restricted to specific institutions ( 23 - 24 ) , or had different objectives, such as evaluating the association between cesareans and prematurity ( 25 ) or the association between access to prenatal care and the occurrence of cesareans ( 26 ) . Other studies employed the Robson Classification to assess the occurrence of cesareans in the country but during periods close to its implementation as a strategy, such as from 2011 to 2017 ( 20 ) , and from 2014 to 2016 ( 27 ) .…”

“…Ainda, outros estudos brasileiros que utilizaram a classificação de Robson foram locais ( 21 - 22 ) , restritos a instituições ( 23 - 24 ) , ou tiveram outros objetivos como avaliar a associação entre cesarianas e prematuridade ( 25 ) ou a associação entre acesso ao pré-natal e ocorrência de cesáreas ( 26 ) . Outros estudos utilizaram a classificação de Robson para avaliar a ocorrência de cesáreas no país, mas em períodos anteriores, muito próximos da sua implementação enquanto estratégia, tais como de 2011 a 2017 ( 20 ) , e de 2014 a 2016 ( 27 ) .…”