External Cephalic Version and Reducing the Incidence of Term Breech Presentation
Scope
This guideline covers external cephalic version (ECV) — manipulation of the fetus through the maternal abdomen to a cephalic presentation — as a means of preventing noncephalic presentation at delivery and reducing caesarean section rates. Intrapartum management of established breech presentation and mode-of-delivery counselling are covered separately in the companion guideline GTG 20b and are not duplicated here.
Background
Breech presentation complicates 3–4% of term deliveries and is more common in nulliparous women and in preterm deliveries. Following the Term Breech Trial, planned vaginal breech birth became rare in the UK, making prevention of breech presentation at term (via ECV) clinically important.
Effectiveness
- A systematic review of 8 trials (1308 women) showed ECV at term reduces noncephalic presentation at delivery (RR 0.42, 95% CI 0.29–0.61) and reduces the chance of caesarean section (RR 0.57, 95% CI 0.40–0.82).
- The overall success rate of ECV is approximately 50%. In a large series, 47% of ECV attempts resulted in cephalic presentation at birth — success is greater in multiparous women (60%) than nulliparous women (40%).
- Spontaneous version from breech to cephalic after 36 weeks is unusual (~8% in primigravidae). After a failed ECV at 36+0 weeks or later, only 3–7% will spontaneously turn cephalic. Spontaneous reversion to breech after successful ECV is rare (~3%).
- Labour after successful ECV still carries a slightly higher risk than spontaneous cephalic presentation: increased obstructed labour (OR 2.2), fetal distress (OR 2.2), and instrumental delivery (OR 1.4) versus babies that were cephalic from the outset.
Predictors of Success
Success cannot be reliably predicted by formal models (insufficient predictive value to alter practice), but favourable factors include: multiparity (OR 2.5), non-engagement of the breech (OR 9.4), use of tocolysis (OR 18), a palpable fetal head (OR 6.3), maternal weight <65 kg (OR 1.8), posterior placental location (OR 1.9), complete breech position (OR 2.3), and amniotic fluid index >10 (OR 1.8). A low predicted probability of success should not preclude an attempt, given the low risk and potential benefit.
Timing
- ECV should be offered at term from 37+0 weeks of gestation; in nulliparous women it may be offered from 36+0 weeks.
- There is no clear benefit to ECV before 36 weeks — earlier ECV (34–35+6 weeks) reduces noncephalic presentation at birth but not the caesarean section rate, and significantly increases preterm birth.
- There is no upper gestational limit, though contraindications become more common with advancing gestation.
- Intrapartum ECV may be considered with informed consent if membranes are intact and no contraindications exist, though evidence is limited.
Tocolysis and Technique
- Tocolysis with betamimetics improves ECV success rates and is supported by Grade A evidence: a 2015 Cochrane review found betamimetics increased cephalic presentation in labour (RR 1.68) and reduced caesarean sections (RR 0.77), in both multiparous and nulliparous women.
- Nifedipine and atosiban lack sufficient evidence of benefit as tocolytics for ECV; IV glyceryl trinitrate was inferior to subcutaneous terbutaline in one small RCT.
- A pragmatic regimen is 250 micrograms salbutamol in 25 ml normal saline (10 micrograms/ml) by slow IV injection, or 250 micrograms terbutaline subcutaneously.
- Betamimetics are contraindicated in significant cardiac disease or hypertension and are ineffective in women on beta-blockers; expect maternal palpitations, tachycardia, flushing, tremor, and occasional nausea.
- Routine regional/neuraxial analgesia is not recommended, but may be considered for a repeat attempt or for women unable to tolerate ECV without analgesia — it requires less force and may reduce failure rates, particularly combined with tocolysis, without evidence of increased complications.
Contraindications
There is no general consensus on eligibility for, or contraindications to, ECV, and evidence is limited — only placental abruption, severe pre-eclampsia, and abnormal fetal Doppler or CTG are evidence-supported contraindications. ECV is generally considered contraindicated where an absolute indication for caesarean already exists (e.g. major placenta praevia), and also in: multiple pregnancy (except after delivery of a first twin), rhesus isoimmunisation, current or recent (<1 week) vaginal bleeding, abnormal electronic fetal monitoring, ruptured membranes, or where the mother declines or cannot give informed consent. Additional caution is warranted with oligohydramnios or hypertension. ECV after one previous caesarean delivery appears to carry no greater risk than in women with an unscarred uterus (no uterine ruptures reported in the largest comparative series, though numbers are insufficient to fully quantify risk).
Risks and Fetal Safety
- With appropriate precautions, ECV has a very low complication rate; large series report no fetal deaths attributable to the procedure, and no significant differences in Apgar scores, umbilical vein pH, neonatal admission, or perinatal death.
- The risk of emergency caesarean section within 24 hours of ECV is approximately 0.5%, most often for vaginal bleeding or an abnormal CTG.
- Fetomaternal haemorrhage can occur even with a prior negative Kleihauer test (detected in 2.4% of women tested shortly after ECV in one series).
- ECV should be performed only where facilities for fetal monitoring and immediate caesarean delivery are available. Standard pre-operative caesarean preparations are not required. Electronic fetal monitoring is recommended following the procedure.
- All D-negative women undergoing ECV should have testing for fetomaternal haemorrhage and be offered anti-D prophylaxis.
- ECV should only be performed by a trained practitioner, or a trainee under direct supervision.
Non-ECV Methods
Moxibustion at 33–35 weeks, under guidance of a trained practitioner, may be considered by women wishing to try it. There is no evidence that postural management alone promotes spontaneous version to cephalic presentation.
High-Yield Exam Points
- ECV success rate: ~50% overall (multiparous ~60%, nulliparous ~40%).
- Offer from 37+0 weeks (all women); may offer from 36+0 weeks in nulliparous women. No benefit starting before 36 weeks (increases preterm birth without reducing CS rate).
- Betamimetic tocolysis (Grade A evidence) is the single best-evidenced way to improve success — salbutamol 250 micrograms IV or terbutaline 250 micrograms SC.
- Only 3 contraindications have direct evidence behind them: placental abruption, severe pre-eclampsia, abnormal fetal Doppler/CTG. Everything else (praevia, multiple pregnancy, Rh isoimmunisation, recent bleeding, ruptured membranes, abnormal EFM) is consensus-based, not evidence-based.
- Prior caesarean section is NOT a contraindication — no increased risk versus unscarred uterus.
- Emergency CS within 24 hours of ECV occurs in ~0.5% of attempts, usually for bleeding or abnormal CTG.
- D-negative women require Kleihauer testing and anti-D after ECV, regardless of outcome.
- ECV reduces caesarean section rate (RR 0.57) but labour after successful ECV still carries higher CS/instrumental delivery/fetal distress risk than a baby that was cephalic all along — know this distinction for exam questions on counselling.
Source: RCOG Green-top Guideline No. 20a (March 2017 (2nd edition; originally published 2006). Impey LWM, Murphy DJ, Griffiths M, Penna LK. BJOG 2017;124:e178–e192.)
Read the original on rcog.org.uk
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