Vaginal Birth After Caesarean Section (vbac)

VAGINAL BIRTH AFTER CAESAREAN SECTION (VBAC) BY DR. E.O.OBI-THOMAS

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INTRODUCTION NOMENCLATURE INCIDENCE TYPES OF INCISION INDICATORS THAT GOVERN OUTCOME OF VBAC – FAVOURABLE – UNFAVOURABLE

• MANAGEMENT OPTIONS – – – –

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PRECONCEPTION PERIOD ANTENATAL PERIOD INTRAPARTUM PUERPERIUM

CONTENTIOUS ISSUES ADVANTAGES SET BACKS CONCLUSION

Introduction • VBAC phenomenon was observed in the second half of last century by chance. • Once a caesarean always a caesarean founded on fear of uterine rupture with classical scar. • Dewhurst noted that in 1957 lower uterine segment scar ruptured and not only in classical scar.

• By 1980 ACO&G formally enclosed a policy of trial of labour for reducing Caesarea section. • Various countries endorsed VBAC with varying degree of urgency.

Nomenclature • From lex caesarea in 700 BC • From Latin word caedere (to cut) or caesum (cut) • Hysterctomy could be vaginal birth after hysterctomy.(VBAH)

Incidence • Success rate 52 – 80%, (lloabachie – Lovell and Adair) • West Africa – 60 (Klufio, Egwuatu Onitfade) Types of incisions • Classical • Lower uterine segment • Transverse incision • De Lee • “J”-incision

Indicators that govern outcome of VBAC • CS was safe with advent of modern bld Transfusion, safer anaesthesia and powerful antibiotics. • Rate of maternal Mortality is still high, ranging from 4-26 times that of vaginal route. (Hale, Creightonx and penn • Risks ranging from anaesthetic through surgical to immediate and long term complications: Puerpeual endomestritis (10 times greater)

– Bound injury, Bladder injury, Ureteric injury, Infections, aspiration pneumonitis (mendelson’s syndrome, DVT and Pul. Embolism, More cost, longer Hospital stay, Delay in mother baby bonding • A Favourable factors – Hx of previous vaginal birth before or after CS – If there was no non-recurrent factor for the previous CS like malpresentation, PIH, social reasons, multiple gestation breech, CPD, etc

– Non-classical incision. – Absence of morbidity in previous CS as evidenced by normal hospital stay – Bishop Score – No hx of uterine perforation in attempt at TOP after CS.

These scores are more applicable in developed countries. • B Unfavourable factors – – – –

Fetal macrosomia IUGR Fetal asphyxia Short birth interval especially inter pregnancy interval less than 6 months – Age, parity, CPD do not impede VBAC

Management options • A Preconception period – – – – – – – –

Counseling Hysterosalpingography Ultrasound Sonohysterography Erect lateral pelvimetry CT MRI

• B Antenatal period – Basically as with most other pregnant women esp. where appropriate preconception care has been given to assess scar thickness and bony pelvic measurement.

• Past obstetric history • Ultrasound measuring 3.5mm or more at 36 wk of gestation is adequate (Rozenberg et al) • Clinical pelvimetry at 36 wks of gestation where pelvic measurement is unknown prior to conception. • Radiological • CT scan (20%) • MRI • Attempt to assess size of fetus is important as macrosomia or IUGR determine outcome of VBAC.

• Before 37 wks of gestation decision to undertake or not to undertake VBAC should have been taken. C Intrapartum • There must be facilities to carry out CS. • Anaestghesiology and neonatology coverage must be available. • Group and Xmatch bld • Wide bore canulla • IVF slowly throughout labour and one hour after labour. • Active management of all stages of labour.

• Continous cardiotocographic monitoring. • Intrauterine pressure monitoring if memb. ruptured - controvasial • Monitor labour on partogram. Important indices to look out for are – – – – – –

Vaginal bleeding Urine colour Maternal pulse. Maternal BP Fetal heart rate

• Time for intervention is when there is evidence of scar rupture, fetal distress, slow progress in labour or CPD.

Evidence of scar disruption • Continuous abd pain • Cessation of uterine contraction. • Vaginal bleeding. • Maternal tachycardia • FHR abnomaliies • Haematuria. D Puerperium • Managed as other birth by vaginal route.

Contentious issues • Oxytocin and prostaglandin for induction or angumentation of labour.

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Use of epidural analgesia. Digital exploration of lower uterine segment. Breech and ECV VBAC after 2 or more CS Set backs • Failure to achieve vaginal delivery. • Compelling recourse to a repeat CS • Failure to convince certain women who had undergone difficult labour in a previous pregnancy to accept VBAC esp. with previous dystocia, malpresentation, fetal distress, fetal macrosomia, oxygen use and gestation age at previous CS

• Poor hospital facilities • Economic factors • Illiteracy levels • Churches. Advantages • Reduction of CS and its hazards • Cheap • Reduce hospital stay • Enhance mother baby bonding. Prevention • By reducing 10 CX

CONCLUSION VBAC should be practised within the ambit of the available facilities in a given health care institution so as not to compromise safety. Developing countries need to take up the challenges posed to them by the practice of VBAC especially in the area of acquiring complex but sensitive modern facilities for managing women at preconception antenatal and intrapartum periods. Obstetricians are better for it if the fear of uterine disruption is put away and VBAC finds a firm place in their obstetric practice.