Delivery Flashcards
Premature rupture of the membranes
PROM
the rupture of fetal membranes at least 1 hour prior to the onset of labour, at ≥37 weeks gestation.
It occurs in 10-15% of term pregnancies, and is associated with minimal risk to the mother and fetus due to the advanced gestation.
Pre-term premature rupture of the membranes (P-PROM)
the rupture of fetal membranes occurring at <37 weeks gestation.
It complicates ~2% of pregnancies and has higher rates of maternal and fetal complications. It is associated with 40% of preterm deliveries.
Pathophysiology of PROM
Early activation of normal physiological processes – higher than normal levels of apoptotic markers and MMPs in the amniotic fluid.
Infection – inflammatory markers e.g. cytokines contribute to the weakening of fetal membranes.
Genetic predisposition
Prolonged rupture of membranes
amniotic sac ruptures more than 18 hours before delivery
risk factors PROM/P-PROM
smoking previous PROM-pre-term delivery vaginal bleeding during pregnancy lower genital tract infection invasive procedures, e.g. amniocentesis multiple pregnancy cervical insufficiency
Prematurity classification
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
clinical features of PROM
painless popping sensation
gush of water
gradualleakage of watery fluid from the vagina
fluid draining from cervix and pooling in posterior vaginal fornix
washed cleann- lack of normalvaginal discharge
options for prophylaxis of pre-term labour
vaginal progesterone
cervical cerclage
vaginal; progesterone for prophylaxis of pre-term labour
Progesterone can be given vaginally via gel or pessary as prophylaxis for preterm labour. Progesterone has a role in maintaining pregnancy and preventing labour by decreasing activity of the myometrium and preventing the cervix remodelling in preparation for delivery. This is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation.
cervical cerclage for prophylaxis of pre-term labvour
Cervical cerclage involves putting a stitch in the cervix to add support and keep it closed. This involves a spinal or general anaesthetic. The stitch is removed when the woman goes into labour or reaches term.
Cervical cerclage is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had a previous premature birth or cervical trauma (e.g. colposcopy and cone biopsy).
“Rescue” cervical cerclage may also be offered between 16 and 27 + 6 weeks when there is cervical dilatation without rupture of membranes, to prevent progression and premature delivery.
PROM differentials
urinary incontinence normal vaginal secretions of pregnancy increased sweat/moisture arounbd perineum increased cervical discharge vesicovaginal fistula loss of mucus plug
investigations for PROM
high vaginal swab for GBS, figure out cause (BV) ferning test actim-PROM amnisure nitrazine testing
ferning test
placing cervical secretion onto a glass slide and allowing it to dry (forming fern-patterned crystals if there is PROM/PPROM). The false positive rate is around 6%.
Actim-PROM (Medix Biochemica)
uses a swab test looking for IGFBP-1 (insulin-like growth factor binding protein-1) in vaginal samples. The concentration in amniotic fluid is 100 – 1000 times the concentration of maternal serum. This test is unlikely to be affected by blood contamination
Amnisure (QiaGen) –
looks for Placental alpha microglobulin-1 (PAMG-1) which is present in the blood, amniotic fluid (in large concentrations) and cervico-vaginal discharge of pregnant women (in low concentrations with membranes intact).
Nitrazine testing
measures the pH of vaginal fluids and has previously been used to diagnose PROM and PPROM (amniotic fluid pH is higher than vaginal fluids). However, this test carried a high false positive rate (17%), due to contamination with urine, blood or semen – and is no longer routinely used.
PROM management >36 weeks
Monitor for signs of clinical chorioamnionitis.
Clindamycin/penicillin during labour if GBS isolated.
Watch and wait for 24 hours (60% of women go into labour naturally), or consider induction of labour.
IOL and delivery recommended if greater than 24 hours (but women can wait up to 96 hours – beyond this is their choice after counselling)
PROM management 34-36 weeks
Monitor for signs of clinical chorioamnionitis, and advise patient to avoid sexual intercourse (can increase risk of ascending infection).
Prophylactic erythromycin 250 mg QDS for 10 days.
Clindamycin/penicillin during labour if GBS isolated.
Corticosteroids if between 34 and 34+6 weeks gestation.
IOL and delivery recommended.
24-33 weeks PROM management
Monitor for signs of clinical chorioamnionitis, and advise patient to avoid sexual intercourse.
Prophylactic Erythromycin 250 mg QDS for 10 days.
Corticosteroids (as less than 34+6).
Aim expectant management until 34 weeks.
diagnossi Pre-term labour with intact membrANES
Clinical assessment includes a speculum examination to assess for cervical dilatation. The NICE guidelines (2017) recommend:
Less than 30 weeks gestation, clinical assessment alone is enough to offer management of preterm labour.
More than 30 weeks gestation, a transvaginal ultrasound can be used to assess the cervical length. When the cervical length on ultrasound is less than 15mm, management of preterm labour can be offered. A cervical length of more than 15mm indicates preterm labour is unlikely.
fetal fibronectin
fetal fibronectin in diagnosis pre-term labour with intact,membranes
Fetal fibronectin is an alternative test to vaginal ultrasound. Fetal fibronectin is the “glue” between the chorion and the uterus, and is found in the vagina during labour. A result of less than 50 ng/ml is considered negative, and indicates that preterm labour is unlikely.
pre-term labour with intact membranes
regular painful contractions
cervical dilatation without rupture of amniotic sac
management of pre-term labour
Fetal monitoring (CTG or intermittent auscultation)
Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour
Maternal corticosteroids: can be offered before 35 weeks gestation to reduce neonatal morbidity and mortality
IV magnesium sulphate: can be given before 34 weeks gestation and helps protect the baby’s brain
Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby at birth
Tocolysis
Tocolysis involves using medications to stop uterine contractions.
Nifedipine, a calcium channel blocker, is the medication of choice for tocolysis.
Atosiban is an oxytocin receptor antagonist that can be used as an alternative when nifedipine is contraindicated.
Tocolysis can be used between 24 and 33 + 6 weeks gestation in preterm labour to delay delivery and buy time for further fetal development, administration of maternal steroids or transfer to a more specialist unit (e.g. with a neonatal ICU). It is only used as a short term measure (i.e. less than 48 hours).
complications of PROM
chorioamnionitis oligohydramnios neonatal death placental abruption umbilical cord prolapse
instrument types for assisted vaginal delivery
ventouse
forceps
maternal indications for assisted vaginal delivery in multiparous women
expect delivery with one hour of active pushing, with an hour for descent if needed prior to active pushing.
maternal indications for assisted vaginal delivery in nulliparous women
as a general rule, expect delivery after two hours of active pushing. If no urge to push is felt at the diagnosis of second stage (common with regional anaesthesia), an hour can be allowed for fetal descent before starting active pushing.
maternal indication for performing an assisted vaginal delivery
inadequate progress
maternal exhaustion
intracranial pathologies, maternal congenital heart diseases and severe HTN
fetal indications for performing an assisted vaginal delivery
fetal compromise
CTG
abnormal fetal blood sample
significant antepartum haemorrhage
absolute contraindications to instrumental delivery
Unengaged fetal head in singleton pregnancies.
Incompletely dilated cervix in singleton pregnancies.
True cephalo-pelvic disproportion (where the fetal head is too large to pass through the maternal pelvis).
Breech and face presentations, and most brow presentations.
Preterm gestation (<34 weeks) for ventouse.
High likelihood of any fetal coagulation disorder for ventouse.
relative contraindications to instrumental delivery
Severe non-reassuring fetal status (‘acute fetal distress’), with station of the head above the level of the pelvic floor – i.e. fetal scalp not visible.
Delivery of the second twin when the head has not quite engaged, or the cervix has reformed.
Prolapse of the umbilical cord with fetal compromise when the cervix is completely dilated and the station is mid cavity.
pre-requisites for instrumental delivery
fully dilated ruptured membranes cephalic presentation defined fetal position fetal head at least at the level of the ischial spines empty bladder adequate pain relief adequate maternal pelvis
fetal complications of instrumental delivery
Neonatal jaundice
Scalp lacerations
Cephalohaematoma
Subgaleal haematoma
Facial bruising
Facial nerve damage
Skull fractures
Retinal haemorrhage
maternal complications of instrumental delivery
VTE
Incontinence
PPH
Shoulder dystocia
Infection
vaginal tears
Indications for induction of labour
prolonged gestation premature rupture of membranes maternal health problems: existing diabetes, pre-eclampsia, obstetric cholestasis fetal growth restriction intrauterine fetal death
bishops score
Fetal station (scored 0 – 3)
Cervical position (scored 0 – 2)
Cervical dilatation (scored 0 – 3)
Cervical effacement (scored 0 – 3)
Cervical consistency (scored 0 – 2)
absolute contraindications for induction of labour
Cephalopelvic disproportion
Major placenta praevia
Vasa praevia
Cord prolapse
Transverse lie
Active primary genital herpes
Previous classical Caesarean section
relative contraindications for induction of labour
Breech presentation
Triplet or higher order pregnancy
Two or more previous low transverse caesarean sections
options for induction of labour
vaginal prostaglandins
amniotomy
membrane sweep
membrane sweep in induction of labour
Membrane sweep involves inserting a finger into the cervix to stimulate the cervix and begin the process of labour.
It can be performed in antenatal clinic, and if successful, should produce the onset of labour within 48 hours.
A membrane sweep is not considered a full method of inducing labour, and is more of an assistance before full induction of labour.
It is used from 40 weeks gestation to attempt to initiate labour in women over their EDD.
vaginal prostaglandins E2 in induction of labour
involves inserting a gel, tablet (Prostin) or pessary (Propess) into the vagina.
The pessary is similar to a tampon, and slowly releases local prostaglandins over 24 hours.
This stimulates the cervix and uterus to cause the onset of labour. This is usually done in the hospital setting so that the woman can be monitored before being allowed home to await the full onset of labour.
cervical ripening balloon in induction of labour
silicone balloon that is inserted into the cervix and gently inflated to dilate the cervix.
This is used as an alternative where vaginal prostaglandins are not preferred, usually in women with a previous caesarean section, where vaginal prostaglandins have failed or multiparous women (para ≥ 3).
artificial rupture of membrane in induction of labour
Artificial rupture of membranes with an oxytocin infusion can also be used to induce labour, although this would only be used where there are reasons not to use vaginal prostaglandins.
It can be used to progress the induction of labour after vaginal prostaglandins have been used.
Oral mifepristone (anti-progesterone) plus misoprostol are used to induce labour where intrauterine fetal death has occurred.
monitoring in induction of labour
Cardiotocography (CTG) to assess the fetal heart rate and uterine contractions before and during induction of labour
Bishop score before and during induction of labour to monitor the progress
uterine hyperstimulation in induction of labour
Uterine hyperstimulation is the main complication of induction of labour with vaginal prostaglandins.
This is where the contraction of the uterus is prolonged and frequent, causing fetal distress and compromise.
complications of uterine hyperstimulation
Fetal compromise, with hypoxia and acidosis
Emergency caesarean section
Uterine rupture
first line induction of labour
vaginal prostaglandins
bishop score >=7
suggests cervix is ripe or favourable
high change of a response to interventions made to induce labour
bishop score <4
labour unlikely to progress naturally and prostaglandin will be required
complications of induction of labour
failure of induction uterine hyperstimulation cord prolapse infection pain increased rate of further intervention vs spontaneous labvour uterine rupture
categories of c section
Category Description
1 Immediate threat to the life of the woman or fetus
2 Maternal or fetal compromise that is not immediately life-threatening
3 No maternal or fetal compromise but needs early delivery
4 Elective – delivery timed to suit woman or staff
indications for planned or elective c section
breech other malpresentations twin pregnancy fetal compromise maternal medical conditions transmissable disease primary genital herpes placenta praevia maternal diabetes with big baby previous major shoulder dystocia maternal request previous 3rd degree tear
pre-op for c-section
FBC and G&S
H2 receptor antagonist, reduces Mendelson’s syndrome
VTE
Layers from skin incision to uterus for C-section
skin camper's fascia scarpa's fascia rectus sheath rectus muscle abdominal peritoneum uterus
immediate complications of c section
Postpartum haemorrhage (>1000ml)
Wound haematoma (increased in patient with large BMI/diabetes/immunosuppressed)
Intra-abdominal haemorrhage
Bladder/bowel trauma (more common in patients who have had previous abdominal surgery)
Neonatal:
transient tachypnoea of the newborn
fetal lacerations (1-2% risk, higher with previous membrane rupture)
intermediate complications of c section
Infection:
urinary tract infection
endometritis
respiratory (higher risk if general anaesthetic used)
Venous thromboembolism
late complications of c section
Urinary tract trauma (fistula)
Subfertility (there is a delay in conceiving compared to women who have had vaginal deliveries)
Regret and other negative psychological sequelae
Rupture/dehiscence of scar at next labour (VBAC)
Placenta praevia/accreta
Caesarean scar ectopic pregnancy
