Using Robson classification system for comparing cesarean section rates in fetal growth restriction

Worldwide, fetal growth restriction (FGR) is the second leading risk factor for neonatal mortality, second only to preterm birth. Our study aimed to determine the possible associations between FGR and cesarean section. This retrospective cohort study was conducted based on clinical data of Dongguan People’s Hospital, Guangdong Province, China, covering the period from 2016 to 2025. Eligible participants were women aged 20 years or older who delivered neonates at a gestational age beyond 28 weeks with a birth weight over 1000 g. According to the Chinese expert consensus on FGR, pregnant women with FGR were stratified into two subgroups: Mild FGR (estimated fetal weight below the 10th percentile) and Severe FGR (estimated fetal weight below the 3rd percentile). The modified Robson classification framework was adopted to evaluate the overall cesarean delivery rate and the proportional contribution of each Robson group to cesarean deliveries. Intergroup shifts in Robson categories between mild and severe FGR patients were further assessed. Cesarean delivery frequencies were calculated for both cohorts, and intergroup comparisons were performed using the chi-square test with prevalence ratios reported. Total of 1756 cases were included: Mild FGR (n = 1260, 71.75%) and Severe FGR (n = 496, 28.25%). Compared with Mild FGR group, Severe FGR group showed a higher percentage in preeclampsia (21.03 vs. 31.25% ; P < 0.001), fetal distress (10.24 vs. 19.35% ; P = 0.003) and umbilical cord torsion(6.98 vs. 10.28% ; P = 0.021). The total cesarean section rate is 64.52%, with 62.38% for Mild FGR group and 69.96% for Severe FGR group. The cesarean section rates were slightly increased in 2016 (72.09%), 2020 (78.00%) and 2025 (64.15%). At the same time, in these three years, the incidence of preeclampsia also increased obviously (39.53% in 2016; 38.00% in 2020; 30.94% in 2025). In two groups, modified Robson Group 1’ was the most common, followed by Groups 10 and 2’. Women with Severe FGR were 1.55 (95% CI, 1.06–2.26) times more likely to undergo a cesarean delivery in Robson Group 1’ ( P = 0.024). Nulliparous women with Severe FGR had the highest conversion-to-cesarean-section rate following a trial of vaginal delivery (18.63%). Moreover, when multiparous women attempted vaginal delivery, women with Severe FGR were 2.5-fold (95% CI, 0.99–6.31) to transfer cesarean section than Mild FGR (12.0% vs. 5.16%; P = 0.045). The cesarean delivery rate in FGR pregnancies is significantly higher than in the general population, with frequent complications including preeclampsia and preterm birth. Severe FGR warrants increased clinical attention. A trial of vaginal delivery can be considered for low-risk FGR women, particularly multiparous women, to lower cesarean delivery rates.