Labour Flashcards
Normal labour
- PROCESS in which FOETUS, PLACENTA & MEMBRANES are EXPELLED via BIRTH CANAL
- SPONTANEOUS + occurs ~ 37 - 42 WEEKS GESTATION
Initiation of labour
- PHYSIOLOGICAL FACTORS NOT FULLY UNDERSTOOD = MULTIPLE THEORIES
- TRIGGERED by PARACRINE & AUTOCRINE SIGNALS generated by MATERNAL, FOETAL & PLACENTAL FACTORS which interlink
- KEY PHYSIOLOGICAL CHANGES OCCURING to allow for FOETAL EXPULSION =
- CERVIX SOFTENS (changing from supportive role to birth canal)
- MYOMETRIAL TONE CHANGES to allow CO-ORDINATED CONTRACTIONS
- PROGESTERONE DECREASES while OXYTOCIN + PROSTAGLANDINS INCREASE to allow INITIATION of LABOUR
Stage 1
LATENT PHASE - CERVIX to COMPLETELY EFFACE + DILATED to 3 cm
ACTIVE PHASE - 3 cm to FULL DILATION (10 cm)
• ANTICIPATED PROGRESS = 0.5 - 1cm per hr
UTERINE CONTRACTION begins at FUNDUS (top of uterus) + MOVE DOWN & ACROSS = EXERTS PRESSURE ON FOETAL POLE, which encourages FLEXION + WELL-APPLIED PRESENTING PART, which in turn puts PRESSURE on CERVIX to THIN & DILATE
CERVIX has to = MOVE FORWARD, SOFTEN, EFFACE, DILATE
Stage 2
- FULL CERVICAL DILATATION - BIRTH of BABY
- PASSIVE SECOND STAGE = FULL CERVICAL DILATION before/in absence of involuntary expulsive contractions, wait for 2hrs for active contractions to begin until help used
- ACTIVE SECOND STAGE = EXPULSIVE CONTRACTIONS/ACTIVE MATERNAL EFFORT is present
- PRIMAGRAVIDA BIRTH = expected w/I 2 HRS of active second stage
- MULTIGRAVIDA BIRTH = expected w/I 1 HR of active second stage
Stage 3
- TIME from BABY’S BIRTH - EXPULSION of PLACENTA & MEMBRANES
- PHYSIOLOGICAL MANAGEMENT = LEAVE MUM & BABY CONNECTED, LET OXYTOCIN KICK IN PHYSIOLOGICALLY & WILL START PUSHING PLACENTA OUT - TAKES LONGER○ NO ROUTINE USE of UTEROTONICS, NO CORD CLAMPING until PULSATION STOPPED, placental delivery by MATERNAL EFFORT
• ACTIVE MANAGEMENT = INJECTION e.g. oxytocin TO SPEED ALONG, WAIT UNTIL CORD GOES WHITE + STOP PULSATING, then CLAMP & CUT, then CONTROLLED CORD TRACTION to REMOVE PLACENTA
○ ROUTINE USE of UTEROTONIC DRUGS, OPTIMAL CORD CLAMPING, CONTROLLED CORD TRACTION
• PROLONGED = if INCOMPLETE w/I 30 MINS of BIRTH (w/ ACTIVE management)/60 MINS of BIRTH (w/ PHYSIOLOGICAL management)
Labour progress + monitoring
- MATERNAL OBSERVATIONS = TEMP, PULSE, BP
- ABDOMINAL PALPATION = LIE of BABY, ENGAGEMENT of BABY, PROGRESS, PERFORM PRIOR to VAGINAL EXAM
- VAGINAL EXAMINATION = CERVIX DILATION, FOETAL HEAD in RELATION to PELVIS, need fully informed consent
- LIQUOR MONITORING = should be CLEAR like WATER/PALE STRAW-LIKE COLOUR○ COLOUR, SMELL, BLOOD
○ 1ST STAGE = listened to EVERY 15 MINS ○ 2ND STAGE = listened to EVERY 5 MINS
- PALPATION of UTERINE MUSCLE CONTRACTION = MONITOR SPEED (resting tone allows baby to recover from contractions) + IF THEY’RE DYING OFF
- EXTERNAL SIGNS = RHOMBOID of MICHAELIS & ANAL CLEFT LINE - can be used if pt. doesn’t want other monitoring
- CARDIOTOCOGRAPHY - HIGH RISK PT./PT. WISHES
Labour mechanism
- DESCENT
- FLEXION (as descent happens, head tucking into chest, smallest diameter hitting pelvis 1st)
- INTERNAL ROTATION of HEAD (after head hits pelvic floor)
- CROWNING + EXTENSION of head
- RESTITUTION (naturally turn towards position in was in utero, if this doesn’t happen is something happening that isn’t allowing it e.g. shoulder dystocia)
- INTERNAL ROTATION of SHOULDERS
- EXTERNAL ROTATION of HEAD
- LATERAL FLEXION (can also be used to help baby along, frees up shoulder to help baby come out)
Labour analgesia
- BREATHING, MASSAGE, TENS (esp. in early stages), PARACETAMOL & DIHYDROCODEINE
- WATER (birthing pools, someone w/ pelvic discomfort may experience increased mobility in birthing pool)
- ENTONOX (inhalational NO & O2, can be used at home as well)
- OPIOIDS (MORPHINE, DIAMORPHINE, PETHIDINE)
- REMIFENTANIL (PT. CONTROLLED ANALGESIA, pt. pushes button when they have a contraction - can be a bit sleepy on it)
- EPIDURAL
- Consider MATERNAL POSITION & MOBILITY to REDUCE PAIN + FACILITATE PROGRESS in LABOUR
Indications of induction
- DIABETES (usually before due date)
- POST-DATES = TERM + 7 DAYS (risk of being born late goes up significantly > 42 weeks e.g. stillbirth)
- MATERNAL HEALTH PROBLEMS necessitating PLANNING of DELIVERY e.g. DVT rx
- FOETAL REASONS e.g. GRWOTH CONCERNS, OLIGOHYDRAMNIOS
- SOCIAL/MATERNAL REQUEST/PELVIC PAIN/BIG BABIES
Induction process
check whether cervix dilated
if cervix not dilated + effaced - vaginal prostaglandin pessaries/cook balloon to ripen cervix
cervix dilated + effaced - amniotomy
after amniotomy - IV oxytocin to achieve contractions (aim for 4 - 5 contraction in 10 minutes)
Problems in labour
Inadequate progress = cephalopelvic disproportion (CPD), malposition, malpresentation, inadequate uterine activity, other reasons for obstruction
Foetal distress
Powers problems
PROGRESS in LABOUR is evaluated by COMBINATION/ABDOMINAL + VAGINAL EXAMINATIONS to determine:
* CERVICAL EFFACEMENT * CERVICAL DILATION * DESCENT of FOETAL HEAD THROUGH MATERNAL PELVIS
SUBOPTIMAL PROGRESS in ACTIVE 1ST STAGE of labour:
* PRIMIGRAVID WOMEN < 0.5 cm per hour * PAROUS WOMEN < 1 cm per hour
INADEQUATE UTERINE ACTIVITY:
* INADEQUATE CONTRACTIONS - FOETAL HEAD WILL NOT DESCEND + EXERT FORCE ON CERVIX + CERVIX WILL NOT DILATE * Can INCREASE STRENGTH + DURATION of CONTRACTIONS by giving SYNTHETIC IV OXYTOCIN to mother * IMPORTANT to EXCLUDE OBSTRUCTED LABOUR in these circumstances as STIMULATION of OBSTRUCTED LABOUR can result in RUPTURED UTERUS
Passages + passenger problems
EPHALOPELVIC DISPROPORTION (CPD):
* GENUINE CPD is RARE * Means FOETAL HEAD IN CORRECT POSITION for LABOUR - but TOO LARGE TO NEGOTIATE MATERNAL PELVIS (& be born) * CAPUT + MOULDING develop)
MALPRESENTATION:
* BREECH - C-SECTION RECOMMENDED * TRANVERSE - C-SECTION
MALPOSITION:
* MORE COMMON * FOETAL HEAD in INCORRECT POSITION for LABOUR + RELATIVE CPD occurs • OCCIPITO-POSTERIOR + OCCIPITO-TRANSVERSE - ABNORMAL
FOETAL DISTRESS:
* FOETUSES WELL-EQUIPPED to DEAL w/ STRESSES of LABOUR * SOME FOETUSES FAIL to COPE * IMPORTANT to AVOID CAUSING TOO MANY CONTRACTIONS (UTERINE HYPER-STIMULATION) - can result in FOETAL DISTRESS due to INSUFFICIENT PLACENTAL BLOOD FLOW
FOETAL WELL-BEING determined by:
* INTERMITTENT AUSCULTATION of FOETAL HEART * CTG - continuous monitoring of foetal heartbeat + uterine contractions (only shows freq. not strength) * FOETAL BLOOD SAMPLING - used when abnormal CTG, provides direct measurement from baby (measure pH + base excess - pH gives measures of likely hypoxaemia) * FOETAL ECG
Situations advised not to labour
Obstruction to birth canal - major placenta praevia, masses
Malpresentations - transverse, shoulder hand, breech
Medical conditions where labour is unsafe for women (although vaginal delivery tends to be safer)
Specific previous labour complications (previous uterine rupture)
Foetal conditions - severely growth restricted babies, severe hydrocephalus
Caesarean section
- ESSENTIAL for MANAGEMENT of OBSTRUCTED LABOUR/FOETAL DISTRESS BEFORE CERVIX FULLY DILATED
- INCREASED RISK of INFECTION. BLEEDING, VISCERAL INJURY, VTE compared w/ vaginal birth
- REDUCED RISK of PERINEAL INJURY compared w/ vaginal birth
