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.
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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.