Takeaway
- Primiparity, BMI >30 kg/m2, prolonged second stage, macrosomia (>4 kg), and having a consultant performing the procedure are risk factors for failed instrumented (forceps or vacuum) delivery.
Why this matters
- 11% of vaginal births in the United Kingdom are instrumented or assisted.
- The failure rate for instrumented deliveries is 5%-10% of those attempted.
- Failed instrumented deliveries are associated with an increased risk for maternal and neonatal morbidity.
- Data can be used to counsel women about the difficulty in predicting success and failure rates of instrumented births.
Key results
- 96.4% had a successful instrumented (ventouse [vacuum], forceps, combined ventouse/forceps) delivery; 3.6% were unsuccessful and were delivered by cesarean delivery (CD).
- Risk factors for failed instrumented delivery included: primiparity, BMI >30 kg/m2, prolonged second stage, macrosomia (>4 kg), and a consultant performing the procedure.
- Haemorrhage ≥1000 mL (20.6% vs 12.4%) and admission to neonatal ICU (17.1% vs 11.4%) were more likely with CD for failed instrumented delivery than successful instrumented delivery.
Study design
- Retrospective cohort study.
- Cohort taken from the maternity system database PROTOS of the UK.
- Patients with attempted instrumented deliveries were identified (n=7945).
- Demographics and labour details were examined and compared.
- Funding: None disclosed.
Limitations
- Lack of data on position and station of the foetal head at the time of delivery.
References
References