Labour

Last updated 25.08.13

 

-  Pregnancy

-  Contraindications to Vaginal Delivery

-  Induction on Labour

-  Mechanism of Labour

-  Stages of Labour

-  Assessment & Management

-  Labour Dystocia

-  Analgesia during Labour

-  Tocolysis

-  Puerperium

 

Definition

-  Regular uterine contractions in conjunction with cervical effacement & dilatation

-  Effacement = entire length of cervix taken into lower segment of uterus

-  Spurious labour = intermittent contractions during latent phase not ass w effacement or cervical dilatation

 

Effacement

 

Features

-  Passenger, Passages & Powers

-  Passenger: head in antero-posterior plane, shoulders laterally

-  Presenting part = fetal part overlying internal of during labour

-  Passages: pelvic shape (gynaecoid vs android/anthropoid/platypoid), vagina, perineum

-  Powers: contractions, maternal effort

-  Primigravid (first) vs Multigravid (subsequent)

-  Mean duration Primigravida 10hrs, Multigravida 5.5hrs

-  Effacement

-  Multips may dilate & become effaced simultaneously

-  Multi os = dilation w some effacement felt as a small canal on VE

-  Primips usually dilate after effacement

-  Show (operculum)

-  Cervical mucus plug lost several hours prior to or after onset of labour

-  OR small bright red blood loss PV in transitional period

-  Episiotomy, forceps/vacuum &/or LUSCS may be indicated if problems arise

-  Recommendation that all labouring women be managend 1:1 by midwife

 

Mechanism of Labour

-  Mnemonic: Does Fondling In Cars Ever Result In Love

-  Descent, Flexion & Internal Rotaton of Head can occur in any order

-  Descent

-  Flexion

-  Internal Rotation of Head

-  Crowning

-  Extension

-  Restitution

-  Internal Rotation of Shoulders

-  Lateral Flexion

 

Progress

-  Effacement & dilation of cervix

-  Head at pelvic brim ROT or LOT

-  Neck flexes to present subocciptobregmatic

-  Head descends & engages pelvis

-  Head reaches pelvic floor & occiput rotates to OA

-  Head delivers by extension

-  Decent continues & shoulders rotate into antero-posterior diameter of pelvis

-  Head restitutes into line with shoulders

-  Anterior shoulder delivered by lateral flexion from downward pressire on head

-  Posterior shoulder delivered by lateral flexion upwards

-  Expulsion of fetus by uterine contraction

 

DDx

-  Brackston Hicks contractions

 

Complications

-  Breech presentation

-  Labour dystocia

-  Cord Prolapse/Presentation

-  Fetal distress

-  Shoulder dystocia

-  Retained placenta

-  Perineal trauma

-  PPH

 

Contraindications to Vaginal Delivery

-  Active HSV genital lesions

-  Previous classical Caesarean section or LUSCS w T or J incision

-  Vasa praevia or major placenta praevia

-  Untreated HIV infection

 

 

 

Stages of Labour

<Labour>

 

1st Stage

-  Begins: onset of labour

-  Ends: full dilation of cervix

-  Dilation of cervix & fetal head descent (partogram)

-  DDx breech

-  VE 2-4/24

-  Station

-  Fetal head in respect to ischial spines

-  Noted as -4 to +4

-  0 = ischial spines

-  Head descent

-  Cervical dilation

-  0 to 10cm

-  Avg rate = 1cm/hr dilation in primigravida

-  Position: OA, ROT, LOT

-  Latent Phase

-  Onset of contractions until full cervical effacement/3cm cervical dilation

-  Usually no latent phase in multigravidas

-  May be reasonable to D/C home if present at <3cm cervical dilation

-  Active Phase (Established Labour)

-  Cervical dilation >3cm, regular contractions >5/60

-  Optimal time for SROM is end of first stage

-  Transitional phase

-  Time fram from cervix around 8cm until fully dilated

-  Often brief decrease in uterine activity

-  Ass w marked maternal restlessness

 

2nd Stage

-  Begin when cervix is fully dilated

-  Ends when fetal head is delivered

-  Descent & rotation of fetal head

-  DDx shoulder dystocia

-  May require surgical assistance: instrumental, LUSCS

-  Commencement of 2nd stage may be indicated clinically by ROM, diltatation & gaping of anus, show

 

3rd Stage

-  Begins: delivery

-  Ends: expulsion of placenta & membranes

-  Actively managed to prevent PPH

-  Syntocinon OR Syntometrine

-  +/- once anterior shoulder delivered

-  Controlled cord traction (CCT)

-  Rub up uterus

-  Prolonged

-  >30min if active management

-  >60min if physiological management

-  Normal blood loss 300ml+/-

-  > 500ml NVD = PPH

-  Insepction of perineum for trauma

 

 

 

Intrapartum Assessment & Management

<Labour>

 

Features

-  Women may call in & alert prior to attending or may present unnanounced

-  On presentation to maternity ward midwife to attend pt

-  Collect womens documentation: VMR, etc.

 

History

-  Contractions

-  Time of onset

-  Frequency, duration, intensity

-  Ruptured membranes

-  Time & mechanism/precipitant

-  Liqour seen: color

-  Vaginal discharge

-  Mucus plug (show)

-  Fetal movements: RFM

-  Review Obs Hx

-  Pregnancy complications: pre-eclampsia, GDM..

-  Breech, cephalic

-  Elective LUSCS, VBAC

-  Review PMH

-  Significant medical illnesses

-  Asthma: use of NSAIDs, Misoprostol

-  Allergies

-  Medications

 

Ix

-  Vitals

-  Temp

-  Fever >38 x1 or >37.5 x2 occasions ?chorioamnionitis, Mx w Abx

-  BP: pre-eclampsia, dehydration

-  HR

-  Dipstick +/- MSU for MCS

-  Ketones: vomiting, dehydration

-  Leuks, nitrates: UTI

 

Abdo palpation

-  Leopold manouvres

-  Lie

-  Presentation

-  Engagement

-  Contractions: intensity, duration, frequency

 

VE

-  Dilatation, effacement, station, position

-  When needed for Mx

-  Prior to FSE

-  For ARM (incl for second twin)

-  Determine engagement of fetal head

-  Exclude cord prolapse

-  Assess progress of labour & exclude labour dystocia or obstructed labour

-  Confirm full cervical dilatation ie: for instrumental delivery

-  Confirm axis of fetus ie: for instrumental delivery

-  Assess presentation of second twin

-  Assess stage of labour

-  +/- R/V 2-4/24

-  At least 4/24 once in established labour

-  NOT performed routinely, should know plan based on result

 

Fetal monitoring

-  All women are offered fetal surveillance during labour

-  Low risk women

-  Maternal choice: IA, CTG

-  IA (Doppler) as minimum

-  Speaker mode

-  Each episode commenced toward end of contraction for 30sec+ after contraction ends

-  Timing

-   Every 15-30min in active 1st stage of labour

-   Every 5min in 2nd stage of labour

-   Every 30sec+ towards end of & after each contraction when actively pushing

-  When to change to CTG

-Abnormal IA

-Development of risk intrapartum risk factors

-  At risk women: continuous external fetal monitoring w CTG

-  Abnormal CTG

 

IV Cannulation

-  Indicated if

-  Previous or high risk for PPH

-  IOL

-  VBAC

-  Large bore cannula: 18G (green)+

-  16G (grey) if able

-  Consideration to use of LA given large bore of cannula

-  Site where not likely to be dislodged

-  Avoid cubital fossa

-  Selective use on dorsum hand

-  Distal forearm best

-  Take FBE + G&H simultaneously

 

Partogram

-  Progress of labour: labour dystocia

-  Recording of findings & interventions

 

Vaginal Discharge

-  Liqour: MSL

-  Bleeding: show, intrapartum haemorrhage (APH), perineal trauma

 

Diet

-  Normal women in labour have no need for restrictions

-  Genreally advisable for clear fluids & light diet once in active labour to prevent aspiration

-  If high risk pt consider IV fluids only in case of need for LUSCS (+/- GA)

-  Monitor for dehydration as may increase duration of labour

 

Activity in Labour

-  Does not decrease need for Syntocinon, operative delivery (instrumental or LUSCS) or neonatal outcomes

-  Should be encouraged unless compromises fetal or maternal monitoring

 

Bladder Mx

-  Keep an eye on urine output

-  Encourage voiding every 2hrs

-  If unable to void on x2 occasions or palpable bladder: IDC or in-out catheter

-  Post delivery void within 1-2hrs (max 6hrs)

-  Consider IDC if Epidural for analgesia

-  Women who receive Epidural or Spinal w instrumental delivery or LUSCS: IDC 6hrs+

 

Delivery Position

-  Upright position (kneeling, standing, squatting)

-  Decreases instrumental deliveries, episiotomies & abnormal fetal heart rate patterns

-  Increases 2nd degree perineal tears & EBL > 500ml (PPH)

-  Supine position should be avoided, but left or right lateral may be used

-  Lithotomy position very common

 

 

References

 

Clinical Obstetrics & Gyaecology, Drife & Macgowan, 2004

Pic (Dilaton + Effacement)

SA Perinatal Practice Guideline: Chapter 5 Normal Pregnancy, labour & puerperium Management, 20/03/2012