Impaired Neonatal Outcome after Emergency Cerclage Adds Controversy to Prolongation of Pregnancy

Abstract

Objective: Emergency cervical cerclage is one of the treatment options for the reduction of preterm birth. The aim of this study is to assess neonatal outcome after cerclage with special focus on adverse effects in very low birth weight infants.

Study design: Retrospective cohort study. Classification of cerclages in history-indicated (HIC, n = 38), ultrasound-indicated (UIC, n = 29) and emergency/ physical examination-indicated (PEIC, n = 33) cerclage. Descriptive analysis of pregnancy and neonatal outcome (admission to NICU, duration of hospitalization, respiratory outcome (intubation, CPAP, FiO2max), neonatal complications (ROP, IVH)). Statistical comparison of perinatal parameters and outcome of neonates <1500 g after cerclage with a birth weight matched control group.

Results: Neonates <1500 g after PEIC show significantly impaired outcome, i.e. prolonged respiratory support (total ventilation in days, CPAP, FiO2max) and higher rates of neonatal complications (IVH ≥ II, ROP ≥ 2). Placental pathologic evaluation revealed a significantly higher rate of chorioamnionitis (CAM) after PEIC. Neonates <1500 g after UIC or HIC show no significant difference in neonatal complications or CAM.

Conclusions: In our study PEIC is associated with adverse neonatal outcome in infants <1500 g. The high incidence of CAM indicates a potential inflammatory factor in the pathogenesis. Large well-designed RCTs are required to give conclusive answers to the question whether to prolong or to deliver.

Fig 1. Proportion undelivered in different types of cerclage.

Fig 1 displays the gestational age at delivery for the different groups of cerclage. There is significant difference of the Kaplan-Meier estimators of the different types of cerclage (Log-rank test, p = 0.003). HIC and UIC differ significantly from PEIC, however there is no significant difference between UIC and HIC (HIC vs. PEIC: p = 0.00132; UIC vs. PEIC: p = 0.00864; HIC vs. UIC: p = 0.509). To control the family-wise error rates for comparing the different distributions, p-values were adjusted for multiple comparisons by Bonferroni correction.

Fig 2. Statistical analysis of neonatal outcome <1500 g.

Fig 2 shows outcome of neonates <1500 g for different types of cerclage as well as for birth weight matched controls (n_control = 373; n_PEIC = 20; n_UIC = 10, n_HIC = 12). A-C Neonates after PEIC show significantly impaired respiratory outcome when compared to corresponding controls (Total ventilation, p = 0.01; CPAP ventilation (continuous positive airway pressure), PEIC: p = 0.01; UIC: p = 0.04; Maximal fraction of inspired oxygen (FiO₂ max), p = 0.01 bars represent means). D Neonates after PEIC are also at higher risk for severe neonatal complications (intraventricular hemorrhage, IVH ≥ II, OR 6.54, 95% CI: 2.11–18.23, p = 0.0007; retinopathy of prematurity, ROP ≥ 2, OR 5.76, 95% CI: 2.04–20.98, p = 0.0028). ¹ due to low case numbers, odds ratios are not applicable; * indicates significant values, p<0.05.