Late pregnancy & Labour Flashcards
Stimulation of Labour
Labour brought on by non-spontaneous means after spontaneous rupture of membranes
Induction of Labour
Artificially bringing on labour using chemical or physical means with membranes usually intact
Augmentation of labour
stimulation of contractions after arrested progress in labour, once active labour has been diagnosed (>4cm)
Normal Labour
‘Labour is normal when it is spontaneous in onset, low risk throughout the labour. Baby is born spontaneously in the vertex position between 37-42wks. After birth women and baby are in good condition’ WHO and NICE
Modified Bishop’s score
Cervical dilation - 4cm
Consistency - firm - med - soft -
Length - >3cm - >2cm - >1cm - <1cm
Position - post - mid - anterior -
Station - -3 - -2 - -1/0 - +1/+2
Score - 1 - 2 - 3 - 4
Induction of Labour (if bishops score 3 or less)
–> PGE2 1mg up to max 4mg PV in 24hrs
If SROM - PGE2 or oxytocin infusion 10u in 49mls
Can also use misoprostol (PGE1) but beware uterine rupture(25mcg 6hrly PV or 50mcg 4hrly PO)
Cervical ripening using mechanical means
Foley cath balloons have no significant evidence base
Induction of Labour (if bishops score >4)
1mg prostin
propress - long acting 10mg prostaglandin pessary left for 24hrs
Consider ARM
Tocolytics
Used to prevent preterm labour -rarely used at term
B2 agonists (salbutamol/terbutaline) if hyperstimulated - 250mcg SC
Can also use atosiban
Nifedipine should not be used to treat HTN at term due to tocolytic activity
First stage of labour (latent)
dilation of the cervix up to 4cm -interrupted and irregular contractions
should be up to 12hrs for primips and 6hrs for multips –> prolonged latent phase usually only diagnosed after 48hrs
Risks of prolonged latent phase (>8hrs)
much more common in primips
Increased risk of LSCS, MEC staining, oxytocin augmentation, NICU admission, reduced Apgars at 5mins
Active 1st stage
Regular, painful contractions with progressive dilation of the cervix - 4cm onwards - expect 0.5cm progress each hour
Partogram
a graphical representation of cervical dilation over time
useful for detecting 2nd stage arrest
Management of delay in the 1st stage of labour
ARM if membranes intact - 2hrly exams
consider augmentation if no progress (oxytocin infusion)
Consider passenger, passages and power (usually the problem in primips)
Record of VE
First do abdominal exam for presentation, fifths palpable, uterine tone, CTG
VE: normal vulva and vagina,clear liqour draining, cervix 6cm dilated, fully effacted, station (relative to iliac spines), is there any caput/moudling etc
Fetal moulding
The scalp bones are able to override each other during the descent through the pelvis
Caput
Coning of the babies head. also known as caput sucadeneum
Second stage of Labour
Full dilation till birth.
Also has a passive phase where additional descent may occur and an active phase where maternal effort is required for pushing
Should last 3hrs with active pushing in primips, 2hrs for multips
3rd stage of labour
from delivery of the baby till delivery of the placenta
Can be active or physiological - active preferred as it reduces the risk of PPH
CCT with uterine guarding (risk of uterine inversion)
Perineal trauma
Episiotomies are used to prevent tearing
Midline in US and mediolateral in UK (lower risk of 3rd/4th degree tears)
Repair of perineal tears
vicryl rapide sutures with local infiltration of LA or pudendal block
Epidural is required for the repair of 3rd or 4th degree tears
Classification of perineal tears
1st - superifical tears to the posterior labial frenulum, vaginal skin and mucosa
2nd - tear extends into the perineal muscles and fascia
3rd - a tear involving the anal sphincter
4th - a tear involving the anal sphincter and rectal mucosa
Subclassification of 3rd degree perineal tears
3a - 50% of the external anal sphincter
3c - Internal sphincter is torn
Cord Prolapse
An acute obstetric emergency. Exposure of the cord can cause irritation and cooling leading to vasospasm. ARM, transverse lie and Footling breech are all risk factors. (all malpresentations or unstable lies)
Varieties of Cord Prolapse
Overt –> The cord slips past the presenting part into the cervix or vagina
Occult –> Where the cord lies alongside the presenting part. 50% of CTGs show some evidence of cord compression but it is usually transient and relieved by changing maternal position.
Funic –> felt to prolapse below the presenting part before the ROM and it may move or disappear as the membranes rupture.
Management of Cord Prolapse
Overt –> place mother in head down, bum up and apply upward pressure to the presenting part manually or by filling the bladder. Do not handle the cord and proceed to emergency CS or expedited VD if well progressed.
Occult –> place mother in LL position and give Oxygen and montior continue if possible or Emergency CS
Funic –> Emergency CS or ARM with prep to convert.
Classical CS
An Upper segement CS with a 1/25 risk of uterine rupture – do not attempt VBAC.
Forceps used in delivery
Outlet (Wrigley’s) –> small and used for CS or when the head is visible and no more than 45 degrees of rotation is needed
Mid-cavity (Neville Barnes) –> where the head is 1/5 palpable or above station +2 and no more than 45 degrees of rotation
Rotational (Keilands) –> only used by experienced staff in theatre. Used to rotate the head, hold it in place and to reduce the risk of cord prolapse after manual disimpaction of the head.
Management of pain after a CS
Paracetamol is first line in pregnancy for pain. Diclofenac is good but cannot be used in pregnancy or if breast-feeding.
Codeine shouldnt be used if breast feeding as it can cause respiratory depression.
Syntometrine/oxytocin challenge test
Oxytocin transiently reduces placental blood flow by inducing a contraction and if this causes a late decleration it indicates fetal hypoxia due to low placental circulatory reserve. This may warrant immediate CS delivery
