Women's Health - Obstetrics Flashcards
Define antepartum haemorrhage and outline the main causes of it
Antepartum haemorrhage (APH) is defined as bleeding from or in to the genital tract, occurring from 24+0 weeks of pregnancy and prior to the birth of the baby.
- Occurs in 5% of pregnancies
Causes:
- No Identifiable cause in 40%
3 important causes:
- placenta praevia - painless bleeding
- placental abruption - painful bleeding
- Vasa praevia
- Infection
me - also uterine rupture
What is low lying placenta vs placenta praevia
Low-lying placenta is used when the placenta is within 20mm of the internal cervical os
Placenta praevia is used only when the placenta is over the internal cervical os. This is subdivided into partial and complete praevia (placenta completely covers the internal os)
Delivery of the placenta before baby is incompatible with survival.
How is placenta praevia diagnosed, inc follow up Ix if present?
Diagnosed at the routine 20-week anomaly scan - used to assess the position of the placenta and diagnose placenta praevia.
The scan is then repeated at 32 weeks (and 36 weeks) because the lower segment of the womb can stretch, if more than 2cm away from the internal os can avoid caesarian section
Many women with placenta praevia are asymptomatic. It may present with painless vaginal bleeding in pregnancy (antepartum haemorrhage). Bleeding usually occurs later in pregnancy (around or after 36 weeks).
Management of delivery for low lying placenta - 2 things
Caesarian section - Planned delivery is considered between 36 and 37 weeks gestation. It is planned early to reduce the risk of spontaneous labour and bleeding. Planned cesarean section is required with placenta praevia and low-lying placenta (<20mm from the internal os).
Corticosteroids are given between 34 and 36 weeks gestation to mature the fetal lungs, given the risk of preterm delivery.
Emergency caesarean section may be required with premature labour or antenatal bleeding.
Advice:
- present if bleeding/pain
-avoid intercourse
- recurrent bleeding may require admission until delivery (remeber that lady in kings)
What is the main complication of placenta praevia and how is it managed? (5 Mx options)
The main complication of placenta praevia is (MASSIVE - ME) haemorrhage before, during and after delivery. When this occurs, urgent management is required and may involve:
Emergency caesarean section
Blood transfusions
Intrauterine balloon tamponade
Uterine artery occlusion
Emergency hysterectomy
The last three are post natal haemorrhage magement.
////
Explainatory Notes on antepatrtum haemorrhage (another card) - if bleeding stops delivery can be delayed
Clinical examination into coexisting symptoms such as pain, an assessment of the extent of vaginal bleeding, the cardiovascular condition of the mother, and an assessment of fetal wellbeing.
An assessment of the fetal heart rate should be performed, usually with a cardiotocograph (CTG) in
women presenting with APH once the mother is stable or resuscitation has commenced, to aid decision
Ultrasound to establish cause of bleeding if unknown
Women with APH and associated maternal and/or fetal compromise are required to be delivered
immediately.
What is vasa praevia? Type I vs II?
Under normal circumstances, the umbilical cord containing the fetal vessels (umbilical arteries and vein) inserts directly into the placenta. The fetal vessels are always protected, either by the umbilical cord or by the placenta.
In vasa praevia, the fetal vessels are exposed, outside the protection of the umbilical cord or the placenta. The fetal vessels travel through the chorioamniotic membranes, and pass across the internal cervical os (the inner opening of the cervix). These exposed vessels are prone to bleeding, particularly when the membranes are ruptured during labour and at birth. This can lead to dramatic fetal blood loss and death.
There are two types of vasa praevia:
Type I vasa praevia – the fetal vessels are exposed as a velamentous umbilical cord (the umbilical cord inserts into the chorioamniotic membranes, and the fetal vessels travel unprotected through the membranes before joining the placenta)
Type II vasa praevia – the fetal vessels are exposed as they travel to an accessory placental lobe
Diagnosis of Vasa praevia
Vasa praevia may be diagnosed by ultrasound during pregnancy. This is the ideal scenario, as it allows a planned caesarean section to reduce the risk of haemorrhage. However, ultrasound is not reliable, and it is often not possible to diagnose antenatally.
It may present with antepartum haemorrhage, with bleeding during the second or third trimester of pregnancy.
It may be detected by vaginal examination during labour, when pulsating fetal vessels are seen in the membranes through the dilated cervix.
Finally, it may be detected during labour when fetal distress and dark-red bleeding occur following rupture of the membranes. This carries a very high fetal mortality, even with emergency caesarean section.
Management of Vasa praevia - if diagnosed antenatally (Asymptomatic) vs diagnosed following antepartum haemorrhage
For asymptomatic women with vasa praevia, the RCOG guidelines (2018) recommend:
Corticosteroids, given from 32 weeks gestation to mature the fetal lungs
Elective caesarean section, planned for 34 – 36 weeks gestation
Where antepartum haemorrhage occurs, emergency caesarean section is required to deliver the fetus before death occurs.
What are the three types of morbidly adherent placenta?
Placenta accreta spectrum refers to when the placenta implants deeper, through and past the endometrium, making it difficult to separate the placenta after delivery of the baby.
There are three distinctions:
- placenta accreta is where the placenta implants at the surface of the myometrium, but not beyond
- Placenta increta is where the placenta attaches deeply into the myometrium
- Placenta percreta is where the placenta invades past the myometrium and perimetrium, potentially reaching other organs such as the bladder
mnemonic: accreta - placenta is at the myometrium, intreat - placenta is in the myometrium, percreta is past the myometrium
Diagnosis and management of morbidly adherent placenta? What are the options after delivery?
Ideally, placenta accreta is diagnosed antenatally by ultrasound. This allows planning for birth. MRI scans may be used to assess the depth and width of the invasion.
Mx w/ early delivery by caesarian (35-37 weeks + antenatal steroids)
It may be diagnosed at birth, when it becomes difficult to deliver the placenta. It is a cause of significant postpartum haemorrhage
The options during caesarean are:
1. Hysterectomy with the placenta remaining in the uterus (recommended)
2. Uterus preserving surgery, with resection of part of the myometrium along with the placenta
3. Expectant management, leaving the placenta in place to be reabsorbed over time. Expectant management comes with significant risks, particularly bleeding and infection.
What is placental abruption? how does it present?
Placental abruption refers to when the placenta separates from the wall of the uterus during pregnancy. The site of attachment can bleed extensively after the placenta separates. Placental abruption is a significant cause of antepartum haemorrhage.
Don’t confuse this with uterine rupture
Placental abruption refers to when the placenta separates from the wall of the uterus during pregnancy. The site of attachment can bleed extensively after the placenta separates. Placental abruption is a significant cause of antepartum haemorrhage.
The typical presentation of placental abruption is with:
- Sudden onset severe abdominal pain that is continuous
- Vaginal bleeding (antepartum haemorrhage)
- Shock (hypotension and tachycardia)
- Abnormalities on the CTG indicating fetal distress
- Characteristic “woody” abdomen on palpation, suggesting a large haemorrhage
- remember concealed abruption - cervical os remains closed and any haemorrhage remains in the uterus - maternal shock and pain appears disproportionate to the amount of bleeding
There is no test- US only rules out placenta praevia as a cause of bleeding.
severities of antepartum haemorrhage
The RCOG guideline (2011) defines the severity of antepartum haemorrhage as:
Spotting: spots of blood noticed on underwear
Minor haemorrhage: less than 50ml blood loss
Major haemorrhage: 50 – 1000ml blood loss
Massive haemorrhage: more than 1000 ml blood loss, or signs of shock
What is maternal sepsis? What is septic shock?
What are the two causes of sepsis in pregnancy?
Sepsis is a condition where the body launches a large immune response to an infection, causing systemic inflammation and affecting the functioning of the organs of the body. It is still the leading cause of maternal death!
Severe sepsis is when sepsis results in organ dysfunction, such as hypoxia, oliguria or raised lactate. Septic shock is defined when arterial blood pressure drops (inflammation -> vasodilation) and results in organ hypo-perfusion.
Two key causes of sepsis in pregnancy are:
Chorioamnionitis
Urinary tract infections
Signs of sepsis, Signs of Chorio, Signs of UTI
The non-specific signs of sepsis include:
Fever
Tachycardia
Raised respiratory rate (often an early sign)
Reduced oxygen saturations
Low blood pressure
Altered consciousness
Reduced urine output
Raised white blood cells on a full blood count
Evidence of fetal compromise on a CTG
MEOWS - maternaity early obstetric warning sustem monitors for the signs of sepsis.
Additional signs and symptoms related to chorioamnionitis include:
Abdominal pain
Uterine tenderness - why Tess did the abdo examine on women with PROM
Vaginal discharge
Additional signs and symptoms related to a urinary tract infection include:
Dysuria
Urinary frequency
Suprapubic pain or discomfort
Renal angle pain (with pyelonephritis)
Vomiting (with pyelonephritis)
Management of maternal sepsis
inc Abx choice
Septic Six- BUFALO!
B- Blood cultures
U - Urine output
F- IV fluids
A - Empirical broad-spectrum antibiotics
L - Blood lactate level
O - oxygen to maintain sats 94-98%
Continous maternal and fetal monitoring (CTG) is required. Emergency C-section is indicated for signs of fetal distress.
Antibiotics used for maternal sepsis:
- piperacillin and tazobactam (tazocin) + gentamicin
- amoxicillin, clindamycin and genatimicin.
amoxicillin - gram positive coverage
Clinda - gram positive coverage
Gent - gram negative coverage.
Chorioamnionitis can be caused by a large variety of bacteria, including gram-positive bacteria, gram-negative bacteria and anaerobes.
Fetal compromise on CTG - what are early, late and prolonged decellarations (how long do they last)? What is one significantly worrying sign on CTG
Early- vagus stimulation, these are normal
Late- hypoxia, fetus not coping
prolonged - compression of the cord
Early decelerations are gradual dips and recoveries in heart rate that correspond with uterine contractions. The lowest point of the declaration corresponds to the peak of the contraction. Early decelerations are normal and not considered pathological. They are caused by the uterus compressing the head the fetus, stimulating the vagus nerve of the fetus, slowing the heart rate.
Late decelerations are gradual falls in heart rate that starts after the uterine contraction has already begun. There is a delay between the uterine contraction and the deceleration. The lowest point of the declaration occurs after the peak of the contraction (they don’t line up!). Late decelerations are caused by hypoxia in the fetus, and are a more concerning finding. They may be caused by excessive uterine contractions, maternal hypotension or maternal hypoxia.
Prolonged decelerations last between 2 and 10 minutes with a drop of more than 15 bpm from baseline. This often indicates compression of the umbilical cord, causing fetal hypoxia. These are abnormal and concerning.
A sinusoidal CTG is a rare pattern to be aware of, as it can indicate severe fetal compromise. It gives a pattern similar to a sine wave, with smooth regular waves up and down that have an amplitude of 5 – 15 bpm. It is usually associated with severe fetal anaemia, for example, caused by vasa praevia with fetal haemorrhage.
What is cord prolaspe?
biggest risk factor?
management?
Cord prolapse is when the umbilical cord descends below the presenting part of the fetus and through the cervix into the vagina, after rupture of the fetal membranes. There is a significant danger of the presenting part compressing the cord, resulting in fetal hypoxia.
The most significant risk factor for cord prolapse is when the fetus is in an abnormal lie after 37 weeks gestation (i.e. unstable, transverse or oblique). Being in an abnormal lie provides space for the cord to prolapse below the presenting part. In a cephalic lie, the head typically descends into the pelvis, without room for the cord to descend.
Management:
Emergency caesarean section is indicated where cord prolapse occurs. A normal vaginal delivery has a high risk of cord compression and significant hypoxia to the baby.
Pushing the cord back in is not recommended -> (handling causes vasospasm).
When the baby is compressing a prolapsed cord, the presenting part can be pushed upwards to prevent it compressing the cord. Woman lies in the left lateral position and Tocolytic medication (e.g. terbutaline) can be used to minimise contractions
KEY - What is a post-partum haemorrhage. What are the two types? What are the main causes?
Postpartum haemorrhage (PPH) refers to bleeding after delivery of the baby and placenta. It is the most common cause of significant obstetric haemorrhage, and a potential cause of maternal death (but not baby- antepartum with praevias and abruption…)
To be classified as postpartum haemorrhage, there needs to be a loss of:
500ml after a vaginal delivery
1000ml after a caesarean section
It can be classified as:
Minor PPH – under 1000ml blood loss
Major PPH – over 1000ml blood loss
It can also be categorised as:
Primary PPH: bleeding within 24 hours of birth
Secondary PPH: from 24 hours to 12 weeks after birth
There are four causes of postpartum haemorrhage, remembered using the “Four Ts” mnemonic:
T – Tone (uterine atony – the most common cause)
T – Trauma (e.g. perineal tear)
T – Tissue (retained placenta) - this is the secondary cause, the others are primary usually
T – Thrombin (bleeding disorder)
KEY - Management of post-partum haemorrhage
Also include management of secondary post-partum haemorrhage
Treat the Cause - 4 Ts:
Stopping the bleeding:
- mechanical stimulation (rubbing) the uterus
- catheritisation (full bladder prevents contraction)
Medical:
- syntocinon (oxytocin)
- Ergometrine - ME - Oxytocin causes rhythmic contractions, while ergometrine causes sustained contractions - together they are syntometrine.
- carboprost (haemobate- prostoglandin analogue -> contraction)
-tranexamic acid (anti-fibrinolytic)
- Misoprostol
Surgical treatment options involve:
Intrauterine balloon tamponade – inserting an inflatable balloon into the uterus to press against the bleeding
B-Lynch suture – putting a suture around the uterus to compress it
Uterine artery ligation – ligation of one or more of the arteries supplying the uterus to reduce the blood flow
Hysterectomy is the “last resort” but will stop the bleeding and may save the woman’s life
Secondary post-partum haemorrhage:
Secondary postpartum haemorrhage is where bleeding occurs from 24 hours to 12 weeks postpartum. This is more likely to be due to retained products of conception (RPOC) or infection (i.e. endometritis).
Investigations involve:
Ultrasound for retained products of conception
Endocervical and high vaginal swabs for infection
Management depends on the cause:
Surgical evaluation of retained products of conception
Antibiotics for infection
What is the only known cause of shoulder dystocia? 4 complications?
1% of vaginal births
Shoulder dystocia is when the anterior shoulder of the baby becomes stuck behind the pubic symphysis of the pelvis, after the head has been delivered. This requires additional obstetric manoeuvres to enable delivery of the rest of the body.
Shoulder dystocia is an obstetric emergency:
The key complications of shoulder dystocia are:
Fetal hypoxia (and subsequent cerebral palsy)
Brachial plexus injury and Erb’s palsy
Perineal tears
Postpartum haemorrhage
Shoulder dystocia is often caused by macrosomia secondary to gestational diabetes.
presentation - not testing just a reminder:
Shoulder dystocia presents with difficulty delivering the face and head, and obstruction in delivering the shoulders after delivery of the head. There may be failure of restitution, where the head remains face downwards (occipito-anterior) and does not turn sideways as expected after delivery of the head. The turtle-neck sign is where the head is delivered but then retracts back into the vagina.
Management of Shoulder dystocia (5 steps)
External manoeuvres:
1. McRoberts manoeuvre involves hyperflexion of the mother at the hip (bringing her knees to her abdomen). This provides a posterior pelvic tilt, lifting the pubic symphysis up and out of the way - 90% resolve here
- Pressure to the anterior shoulder involves pressing on the suprapubic region of the abdomen. This puts pressure on the posterior aspect of the baby’s anterior shoulder, to encourage it down and under the pubic symphysis. (backs to maternal right/left - want to push on the back of the sholder)
Then internal manoeuvres:
3. rotational manoeuvre (rubins) - hands inside vagine push posterior aspect of anterior sholder and anterior aspect of posterior cholder to twist shoulders under the pubic synthesis
4. remove the posterior arm
- If internal manoeuvres fail - Zavanelli manoeuver involves pushing the baby’s head back into the vagina so that the baby can be delivered by emergency caesarean section.
What are the three stages of labour?
What is partogram used for? What is monitored on the partogram and what does is crossing the alert line an indication for?
First stage (until 10cm dilation of the cervix) - subdivided into:
- latent first stage (up until 4cm)
-active first stage (active labour) (from 4cm-10cm)
Second stage - 10cm to delivery of the fetus
Third stage - from delivery of the fetus to delivery of the placenta
Partogram is for the First stage only! (remember second stage- pushing takes 1/2 hours)
Women are monitored for their progress in the first stage of labour using a partogram - cervical dilation and fetal head descent recorded amongst other things. Crossing the alert line is an indication for amniotomy (artificially rupturing the membranes) and a repeat examination in 2 hours. Crossing the action line means care needs to be escalated to obstetric-led care and senior decision-makers for appropriate action.
**Failure to progress in the first stage is less than 2cm dilation every 4 hours. **
How long should the second stage of labour last?
The success of the second stage depends on “the three Ps”: power, passenger and passage. Delay in the second stage is when the active second stage (pushing) lasts over:
2 hours in a nulliparous woman
1 hour in a multiparous woman
What is involved in active management of the third stage of labour?
Active management involves intramuscular oxytocin and controlled cord traction.
Management of Failure to Progress (4 options)
The main options for managing failure to progress are:
- Amniotomy, also known as artificial rupture of membranes (ARM) for women with intact membranes
- Oxytocin infusion
- Instrumental delivery (second stage only)
- Caesarean section
remember this is both first and second stage
Oxytocin is used first-line to stimulate uterine contractions during labour. It is started at a low rate and titrated up at intervals of at least 30 minutes as required. The aim is for 4 – 5 contractions per 10 minutes. Too few contractions will mean that labour does not progress. Too many contractions can result in fetal compromise, as the fetus does not have the opportunity to recover between contractions.
The condition of the fetus needs to be monitored throughout labour and delivery. Fetal compromise may mean delivery needs to be expedited, or example, with emergency caesarean section.
Physiology of the second stage of labour - what are the 7 cardinal movements?
Why these movements - key understanding
Engagement: This occurs when the largest part of the baby’s head (usually the biparietal diameter) enters the pelvis. The baby is “engaged” in the pelvic inlet and begins the descent through the birth canal.
Descent: The baby moves downward through the birth canal, guided by uterine contractions. The descent is a continuous process throughout labor.
Flexion: The baby’s head flexes forward (chin to chest), allowing the smallest part of the head to present to the birth canal. This is essential for the head to fit through the pelvis.
Internal rotation: As the baby continues to descend, the head rotates to align with the mother’s pelvic axis, turning to face the mother’s back (occiput anterior position) in most cases. This helps the baby’s head fit more easily through the pelvic opening.
Extension: Once the baby’s head reaches the perineum, it extends backward as it emerges from the birth canal. The baby’s head is pushed out with the face first, followed by the chin and neck.
External rotation (Restitution): After the head is born, the baby’s head rotates externally to its original position (in relation to the body). This allows the shoulders to align for birth.
Expulsion: This is the final movement, where the baby’s shoulders and body are delivered after the head is out. The shoulders pass through the birth canal, followed by the rest of the body.
Explanation
- the pelvic inlet is widest side to side, the pelvic outlet is widest front to back
- the fetal skull is widest front to back (sagittally)
- enters the pelvic inlet Occiput tranverse so that the widest part of the skull aligns with the widest part of the pelvis, then internally rotates to exit at the pelvis outlet
- flexion of the head (chin to chest) - reduces the diameter of the head, if baby is OP this also increases diameter because baby can’t flex
- extend head around the pubic synthesis
-external rotation because shoulders are wider (not as long as the head sagittally, but wider than it coronally)
mnemonic - Every Day Fine Infants Enter Eager and Excited
Diagnosing the onset of labour - 4 signs?
The signs of labour are:
- Show (mucus plug from the cervix)
- Rupture of membranes
- Regular, painful contractions (vs Braxton hicks which are occasional irregular contractions of the uterus - KEY)
- Dilating cervix on examination
Summary of intrahepatic cholestasis of pregnancy
- what is it
- when does it present
- pathophysiology and presentation
- complication
- Ix
- Mx
Obstetric cholestasis is characterised by the reduced outflow of bile acids from the liver.
Occours in roughly 1% of pregnancies and usually presents with the third trimester
Bile acids are produced from the breakdown of cholesterol in the liver. In obstetric cholestasis the processing and outflow of bile acids is reduced and meaning that they build up in the blood. This causes pruritis (particularly in the palms of the hands and soles of the feet).
Complication - Bile acids are fetotoxic and OC is is associated with increased risk of stillbirth
Obstetric cholestasis will cause:
- Abnormal liver function tests (LFTs), mainly ALT, AST and GGT
- Raised bile acids
LFTs and bile are used for monitoring- weekly. (if substantially elevated delivery is brough foward). Remeber ALP normally rises in pregnancy due to placental production. Other Ix - OC is a diagnosis of exclusion so other cause of raised LFTs are ecluded - hepititis bloods, US liver.
Management:
- The condition resolves after delivery of the baby - if LFTs deranged this needs to be brought forward to reduced risk of stillbirth
- emollients, topical menthol
- anti-histmamine help with sleeping, not itching (bile acids not histmaine causing the itch)
- vitamin K if PT is deranged
- Formerly used ursodeoxycholic acid - no longer advised
Premature labour - definition and 3 classifications
Birth before 37 weeks gestation. The more premature, the worse the outcomes.
Babies born before 24 weeks are not concidered viable.
The WHO classify prematurity as:
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
Define PROM, P-PROM and PLWIM
Different to a SROM (spontaneous - with contractions)
PROM - prelabour rupture of membranes - when fetal membranes rupture (waters break but contractions don’t occour) past 37 weeks gestation.
P-PROM - Preterm prelabour rupture of membranes is where the amniotic sac ruptures, releasing amniotic fluid, before the onset of labour and in a preterm pregnancy (under 37 weeks gestation).
PLWIM: Preterm labour with intact membranes involves regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
KEY - This has different Ix but basically the same management!
Prophylaxis of preterm labour?
Indications for a rescue suture?
This is for women who are found to have a short cervix I assume on routine scanning:
Vaginal progesterone:
cervical legnth <25mm between 16-24 weeks -> vaginal progesterone to decrease mymoetrium actvitiy and cervic remodelling
Prophalactic cervical cerclage - cervical legnth <25mm between 16-24 weeks + a previous premature birth or cervical traima (colposcopy + cone biopsy)
Rescue cervical cerclage - between 16-28 weeks where Painless cervical dilation occours without ROM to prevent progression and premature delivery. Contractions (painful tightenings), signs of chorio and ROM are absolute contraindications.
Investigations for PROM
Management for PROM vs P-PROM
Ix for PROM/P-PROM:
Rupture of membranes can be diagnosed by speculum examination revealing pooling of amniotic fluid in the vagina. No tests are required.
Where there is doubt about the diagnosis, tests can be performed:
- Insulin-like growth factor-binding protein-1 (IGFBP-1)
- Placental alpha-microglobin-1 (PAMG-1)
Management if at term - PROM:
- IOL if not spontaneously in labour by 24 hours
- Antibiotics - Pen G only given if GBS isolated
- monitor for signs of Chorio
Management if Preterm - PROM (before 37 weeks):
- Prophylactic Erythromycin for 10 days, or until labour is established if within ten days
- Induction of labour may be offered from 34 weeks to initiate the onset of labour
Note - steroids may be given between 34-36 weeks but IOL should not be delayed after 34 weeks
Additionally if before 34 weeks:
Aim here is for increased gestation!!
- Prophylactic Erythromycin for 10 days, or until labour is established if within ten days
- 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 - given within 24 hours of labour
- Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour - given before 34 weeks to allow time to give the corticosteroids
- IOL at 34 weeks but not before (aim to get to 34 weeks)
Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby at birth
Me- Erythromycin is only given to the preterms!
Key Card:
What is preterm labour with intact membranes?
Ix?
Management of PLWIM
Preterm labour with intact membranes involves regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
Diagnosis:
<30 weeks - clinical
>30 weeks - TV USS shows cervical length less than 15mm (above this preterm labour is unlikely)
Foetal fibronectin is an alternative test to vaginal ultrasound. Foetal fibronectin is the “glue” between the chorion and the uterus, and is found in the vagina during labour.
Management of Preterm labour
- CTG monitoring
- tocolysis with nifedipine (CCB) - only for 48 hours to buy time for steroids and IV magnesium sulphate
- maternal corticosteroids (before 35 weeks) - reduce respiratory distress syndrome (2 doses 24 hours apart)
- IV magnesium sulphate (before 34 weeks) - neuroprotection (cerebral palsy). Given within 24 hours of delivery
- delayed cord clamping - increase circulating blood volume and Haemoglobin in the baby
ME - Preterm Labour whether just a PPROM (not contracting but membranes ruptured) or a PLWIM (contracting but membranes intact) is managed exactly the same way. If before 34 weeks you try and give 2 doses of IM betamethasone and IV mag sulphate, using tocolysis to buy time. Erythromycin is given to everyone before 37 weeks if the membranes break. You aim to get women before 34 weeks to 34 weeks and then once at 34 weeks you try and Induce labour - i think the baby is grown enough basically….
For women given IV magnesium sulphate, what monitoring is required?
Mothers need close monitoring for magnesium toxicity at least four hourly. This involves close monitoring of observations, as well as tendon reflexes (usually patella reflex). Key signs of toxicity are:
Reduced respiratory rate
Reduced blood pressure
Absent reflexes
Lecture - what are the four stages of cervical remodelling?
cervical remodelling - occurs in four phases. It becomes soft and stretchy so that it is ready for birth.
1. Softening (no loss of strength).
2.Ripening- loss of strength. KEY TO KNOW THIS APPARENTLY
3. Dilation happens with contractions
4. Repair - post partum.
Lecture - what is the most common cause of preterm birth?
Most common cause of preterm birth is infection:
- intrauterine bacterial infections - could be ascending from vagina
- blood borne transplacental infection
- retrograde from the fallopian tube, iatrogenic during invasive procedures
Explanation - the infection triggers an inflammatory response that causes the cervix to ripen and the uterus to contract.
Others:
- Ischemia - common placental findings in those without infection. If there is insufficient blood flow to the placenta due to invasion of the spiral arteries in formation, then causes still birth or small for dates
- uterine overstimulation - stretching more than expected than gestation (twins, polyhydramnios, uterus structural anomaly) might activate the uterus early than expected
- Cervical weakness - previous surgery (LLETZ for CIN), interrupted structural integrity
What is the biggest risk factor for abnormally adherent placenta?
How is it diagnosed?
The major risk factors for placenta accreta spectrum are previous caesarean delivery, history of accreta in a previous pregnancy, and other uterine surgery.
Women with a history of previous caesarean section seen to have an anterior low-lyingmplacenta (where teh scar is you knob!) or placenta praevia at the routine fetal anomaly scan should be specifically screened for placenta accreta spectrum.
Ideally, placenta accreta is diagnosed antenatally by ultrasound. This allows planning for birth. MRI scans may be used to assess the depth and width of the invasion.
Can be a cause of post-partum haemorrage, also diagnosed with difficulty delivering the placenta, if diagnosed antenatally.
When Triaging a pregnant lady what 3 key Sx do the midwives ask - useful things for your history
Movements
Pain
Bleeding or fluid loss from down below
What is a normal fetal heart rate
110-160 bpm
Management of reduced fetal movements?
Side note - Diagnostic Ix for stillbirth?
Reduced fetal movements are usually nothing serious but occassionally they are a sign of fetal death. A Hx needs to consider risk factors for IUD such as FGR, congential abnormalities and placental insufficiency (inc pre-eclampsia)
- Auscultate the fetal heart to exclude fetal death
- CTG to exclude fetal compromise if the pregnancy is over 28+0 weeks of gestation.
- Ultrasound scan assessment should be undertaken as part of the preliminary investigations of a woman presenting with RFM after 28+0 weeks of gestation if the perception of RFM persists despite a normal CTG or if there are any additional risk factors for FGR/stillbirth.
Ultrasound scan assessment should include the assessment of abdominal circumference and/or estimated fetal weight to detect the SGA fetus, and the assessment of amniotic fluid volume. THIS CAME UP
Note for stillbirth - Ultrasound scan is the investigation of choice for diagnosing intrauterine fetal death (IUFD). It is used to visualise the fetal heartbeat to confirm the fetus is still alive. (Management is Vaginal birth with IOL - first line).
SUMMARY CTG and USS
What is the bishop score and when is it used?
USED TO MONITOR IOL - The bishop score is an assessment of ‘cervical ripeness‘ based on measurements taken during vaginal examination. It is checked prior to induction, and during induction to assess progress:
- A score of 7 - suggests the cervix is ripe or ‘favourable’ – this means that there is a high chance of a response to interventions made to induce labour (i.e amniotomy).
- A score below this suggests cervical ripening (vaginal prostaglandins) may be required to prepare the cervix.
- Failure of a cervix to ripen despite use of prostaglandins may result in the need for a caesarean section.
NOTE- remember prostaglandins are just preparation for an IOL, not the IOL itself (IOL is booked days later at sheffield - amniotomy and syntocinon).
Five things are assessed and given a score based on different criteria (minimum score is 0 and maximum is 13):
Fetal station (scored 0 – 3)
Cervical position (scored 0 – 2) - posterior (hard to reach), mid/anterioir - look at a diagram
Cervical dilatation (scored 0 – 3)
Cervical effacement/legnth (scored 0 – 3)
Cervical consistency (scored 0 – 2) - firm, average or soft
Methods of 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, performing it increases the likelihood of spontaneous delivery, reducing the need for a formal induction. It is used from 40 weeks gestation to attempt to initiate labour in women over their EDD.
Vaginal Prostaglandins - Vaginal prostaglandins form the mainstay of induction of labour, and are the preferred primary method as advised by NICE guidelines (2008). Prostaglandins act to prepare the cervix for labour by ripening it, and also have a role in the contraction of the smooth muscle of the uterus.
Cervical ripening balloon - applies pressure about and blow the cervix which softens and dilates the cervix so that amniotomy can then be used. It is used when vaginal prostaglandins are not preferred. Previous C-section (scar dihesence risk), multiparous women or prostaglandins have failed.
Amniotomy releases prostaglandins in an attempt to expedite labour. It is only performed when the cervix has been deemed as ‘ripe’ (see Bishop Score below). Often, an infusion of artificial oxytocin (Syntocinon) will be given alongside an amniotomy, acting to increase the strength and frequency of contractions. The aim is to start low and titrate upwards until there are 4 contractions every 10 minutes. NICE guidelines (2008) advise that amniotomy +/- oxytocin should NOT be used as the primary method of IOL, unless use of prostaglandins are contraindicated e.g. high risk of uterine hyperstimulation.
CTG monitoring and the bishop score are used to monitor induction of labour.
ME - for VBAC, prostaglandins cannot be used, oxytocin is sometimes used with caution but increases risk of uterine rupture