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Soft versus rigid vacuum extractor cups for assisted vaginal delivery
1Academic Department of Obstetrics and Gynaecology, North Staffordshire Hospital NHS Trust, Maternity Hospital, Newcastle Road, Stoke-on-Trent, Staffordshire, UK, ST4 6QG. rbj@kogs.demon.co.uk
The Cochrane Database of Systematic Reviews
|May 5, 2000
Summary
Soft vacuum extractor cups have a lower success rate but reduce fetal scalp injury compared to rigid metal cups. Maternal injury rates were similar between the two types of vacuum extractor cups.
Area of Science:
- Obstetrics and Gynecology
- Medical Device Technology
- Perinatal Care
Background:
- Vacuum extraction delivery has evolved from rigid metal cups to softer, flexible materials.
- Concerns exist regarding the efficacy and safety of soft cups compared to traditional metal cups.
- Soft cups are hypothesized to cause less fetal and maternal trauma.
Purpose of the Study:
- To compare the effectiveness and safety of soft versus rigid vacuum extractor cups.
- To evaluate outcomes including perineal injury, fetal scalp injury, and delivery success rates.
Main Methods:
- Systematic review of nine controlled trials involving 1375 women.
- Searched Cochrane Pregnancy and Childbirth Group and Cochrane Controlled Trials Registers (up to February 2000).
- Trial quality was assessed, and data were extracted by two independent reviewers.
Main Results:
- Soft cups demonstrated a significantly lower success rate for achieving vaginal delivery (OR 1.65, 95% CI 1.19-2.29).
- Soft cups were associated with significantly less fetal scalp injury (OR 0.45, 95% CI 0.15-0.60).
- No significant difference in maternal injury was observed between soft and rigid cup groups.
Conclusions:
- Rigid metal cups may be preferable for complex fetal presentations (e.g., occipito-posterior, transverse, difficult occipito-anterior).
- Soft cups appear suitable for less complicated, straightforward deliveries.
- The choice of vacuum extractor cup should consider fetal position and delivery complexity.
