OBSTETRICS Flashcards
Where is the oocyte normally fertilised and what does it become?
In the ampulla of the fallopian tubes, a zygote
What happens after fertilisation?
Zygote divides mitotically as it is swept to the uterus, becoming a morula then a blastocyst which implants into the endometrium 6-10 days after ovulation
What is the trophoblast?
Outer layer of the blastocyst which becomes the placenta.
What is the function of hCG and where is it produced?
Produced by the trophoblast (placenta). Maintains the corpus luteum to produce progesterone and oestrogen. until 12 weeks when placenta takes over
When is the placenta formed?
by 12 weeks, by trophoblastic proliferation leading to formation of chorionic villi
What is the blastocyst made up of?
Inner cell mass becomes the embryo, trophoblast becomes the placenta (inner cytotrophoblast and outer syncytiotrophoblast)
When does organogenesis occur including heartbeat?
Organogenesis is 2-8 weeks after conception, heartbeat established by 4-5 weeks and detectable by 6 weeks on TVUSS
What are spiral arteries?
Maternal arteries that occupy intervillous space in the placenta. Converted to larger vessels for increased blood flow, failure of which can lead to IUGR and eclampsia
What are the constituents of the umbilical cord?
2 arteries (deoxygenated blood from foetus to placenta) and 1 vein (oxygenated from placenta to foetus)
What is the blood supply of the uterus?
Uterina and ovarian arteries
Cardiac/heamatological physiological changes of pregnancy
40% increase in plasma volume, 20% increase in RBC (haemodilution)
40% increase in cardiac output
increased clotting risk
Respiratory physiological changes of pregnancy
40% increase in tidal volume, oxygen demand increases by 15%
Metabolic physiological changes of pregnancy (4)
increased urinary protein loss
insulin secretion doubles
cortisol rises
increased calcium demand
What is labour?
Expulsion of foetus and placenta from the uterus, occurring at 37-42 weeks gestation normally. Painful uterine contractions accompany dilatation and effacement of the cervix to facilitate.
What are the stages of labour?
Stage 1 - full dilatation of cervix (early labour is gradual effacement and dilatation <3cm, active labour is more rapid with more forceful contractions)
Stage 2 - fully dilated cervix to delivery of foetus
Stage 3 - from delivery of foetus to delivery of placenta
What are the mechanical factors involved in pregnancy?
Powers (force expelling foetus)
Passage (pelvic dimensions, resistance of tissue)
Passenger (diameter of foetal head)
How long on average does stage 1 labour take?
10hr nulliparous, 6hr multiparous
Describe stage 1 labour (5)
Contractions 2-3 minutes apart
Amniotic membranes rupture
Cervical effacement and dilatation - Latent phase <3cm, active 3-10cm
Head descends from engaged position
90 degree rotation from occipito-transverse to occipito-anterior facing down (or posterior)
Describe stage 2 labour
Faster, stronger contractions
Head descends and flexes
Pushing starts when head reaches pelvic floor
Head extends as delivery occurs and rotates back to transverse before shoulders deliver
Describe Stage 3 labour?
Placental delivery up to an hour after birth
What is misoprostol and what does it do?
Prostaglandin.
Causes effacement of the cervix and contractions, given to induce labour
What is oxytocin and what does it do?
Hormone that induces labour released from posterior pituitary, only if cervix is ripe. (synctocinon given if prostaglandins haven’t induced labour)
What is prolactin and what does it do?
Hormone produced by the anterior pituitary, important role in breastfeeding
Define small for dates
Small for gestation, below the 10th centile. (10% of foetuses)
Constitutional causes of small for dates (4)
Small mother, nulliparous, Asian, female foetus
Pathological causes of small for dates/IUGR (5)
Maternal disease - pre-eclampsia, infection Multiple birth Smoking, drugs Malnutrition Congenital abnormality
8 risks of small for dates/IUGR
Stillbirth Cerebral palsy Prematurity Maternal mortality (c section) Jaundice Feeding problems NEC Hypoxia
Symptoms of IUGR (3)
Reduced foetal movements
Pre-eclampsia
Plateau of symphysis-fundal height
Diagnosis of IUGR
USS to determine if SFD
Serial USS and umbilical artery doppler
Reduced amniotic fluid
If consistent growth and normal doppler, constitutional SFD not pathological and no intervention.
What would umbilical artery doppler show if IUGR
Foetal redistribution of blood to middle cerebral artery - head sparing
What is symmetrical and asymmetrical IUGR
Symmetrical - whole foetus small
Asymmetrical - distribution of blood to vital organs i.e. brain, heart. Have normal head size but small body and limbs, likely placental insufficiency
Management of IUGR at term if abnormal doppler?
Delivered at 36 weeks by induction or c section
Management if preterm IUGR and abnormal doppler?
Prevent stillbirth and neurological damage
Maximise gestation
If absent end diastolic flow indicating vascular distress, give steroids if before 34 weeks to mature lungs and admit
C section delivery
Define pregnancy induced hypertension
When blood pressure rises above 140/90mmHg after 20 weeks
What is pre-eclampsia?
A disorder in which hypertension and proteinuria (0.3g/24hr) appear in the second half of pregnancy, often with oedema
What is eclampsia?
The occurrence of epileptiform seizures in pregnancy where there is hypertension
What is gestational hypertension?
New hypertension presenting after 20 weeks WITHOUT proteinuria
What causes pre-eclampsia?
Of placental origin - spiral arteries fail to fully convert due to incomplete trophoblastic invasion, leading to reduced flow increased resistance and hypertension
How does pre-eclampsia affect maternal organs?
Blood vessel endothelial damage and exaggerated inflammation leads to vasospasm, increased capillary permeation and clotting dysfunction affecting organs
Proteinuria due to increased vascular permeability
Eclampsia due to reduced cerebral blood flow
How does pre-eclampsia affect the foetus? (4)
Reduced placental blood flow causing IUGR
Preterm birth
Placental abruption
Hypoxia
Risk factors for pre-eclampsia (9)
First pregnancy Family history Long time between pregnancys Obesity Extremes of age Chronic hypertension or renal disease Diabetes Antiphospholipid disease Multiple pregnancy
Symptoms of pre-eclampsia
Usually asymptomatic Headache Drowsiness Visual disturbance Nausea Oedema
What is HELLP syndrome?
Considered a variant of pre-eclampsia:
Haemolysis
Elevated liver enzymes
Low platelets
How is HELLP syndrome treated?
Supportive
Magnesium sulfate prophylaxis
Complications of pre-eclampsia (5)
HELLP Stroke DIC Liver or renal failure Pulmonary oedema
How is pre-eclampsia monitored?
Regular blood pressure and urinalysis
Uterine artery Doppler at 23 weeks
Low dose aspirin before 16 weeks if at risk
When is pre-eclampsia managed in the community?
If no proteinuria or BP <160/110, outpatient with twice weekly BP/urinalysis and two weekly USS
When is a woman admitted for pre-eclampsia? (4)
If symptomatic
>0.3g/24hr proteinuria
BP >160/110
Suspected foetal distress
How is pre-eclampsia treated
Labetalol for BP if >150/100
Magnesium sulfate IV - delivery indicated
Steroids if <34 weeks
Deliver
When should baby be delivered in mild, moderate and severe pre-eclampsia
Mild by 37 weeks
Moderate-severe 34-36 weeks
If maternal complications, whenever
What needs to be checked when giving magnesium sulfate for pre-eclampsia
Patellar reflexes as absence precedes respiratory depression
Renal function
Risks of HIV during pregnancy (5)
Pre-eclampsia Prematurity IUGR Stillbirth Vertical transmission
How if HIV treated in pregnancy?
Combination antiretroviral therapy
Elective C-section
Avoid breastfeeding
What is CMV?
Cytomegalovirus, 40% chance of transmission to baby if mother infected during pregnancy.
What are foetal complications of CMV infection? (7)
Deafness - 10% severely affected Learning difficulty Vision impairment Low birth weight Microcephaly Hepatosplenomegaly Rarely, fatal
Foetal complications of rubella infection? (5)
Deafness
Eye abnormalities - retinopathy, cataract
Congenital heart disease
Systemic effects - liver, spleen, LBW
Later life - autism, schizophrenia, developmental delay, learning disability
Prevention of rubella infection?
Termination offered if before 16 weeks
Vaccination
Management of herpes simplex infection during pregnancy
C-section if primary infection <6 weeks before delivery
Aciclovir given
Symptoms of foetal herpes infection (3)
Skin/eyes/mouth herpes - no internal involvement
CNS herpes - encephalitis, seizures
Disseminated herpes - particularly affects liver
Group B streptococcus infection and treatment
High maternal carrier rate causing severe neonatal illness, more common in preterm.
Treat with penicillin intrapartum IV if positive 3rd trimester screen or high risk
Complications of group B strep infection in the baby (4)
Trouble breathing
Unresponsive
Extremes of temperature
Can cause sepsis, meningitis
Complications of group A streptococcus in pregnancy (3)
Chorioamnionitis
Puerperal sepsis
Treat with Abx
Herpes zoster infection during pregnancy
Many immune to chickenpox
If <20 weeks can be teratogenic
Infection close to delivery needs IgG for neonate
Symptoms of foetal varicella syndrome (4)
Patches of scarred skin or skin loss
Limb hypoplasia
Microcephaly
Vision problems
Hepatitis B risk during pregnancy
High risk of transmission and foetal mortality
Screen, if needed give neonatal immunoglobulin
Chlamydia risk in pregnancy
Causes preterm delivery
Neonatal conjunctivitis
Screen in case antibiotics needed
Risk of bacterial vaginosis during pregnancy
Preterm labour - treat if previous preterm birth clindamycin
Define antepartum haemorrhage
Bleeding from the genital tract after 24 weeks gestation (up to 24 weeks is threatened miscarriage)
3 common causes of APH
Undetermined origin
Placental abruption
Placenta praevia
3 rarer causes of APH
Incidental pathology
Uterine rupture
Vasa praevia
What is placenta praevia?
Implantation of the placenta in the lower section of the uterus - at 20 weeks many placentas are low, but most move upwards and only 10% are low at term
Types of placenta praevia (4)
Type I - low lying placenta
Type II - marginal (not covering os)
Type III - major (partially covering os)
Type IV - major (completely covering os)
Risk factors for placenta praevia (4)
Twin pregnancy
High parity
Age
Scarred uterus
Why is placenta praevia problematic?
Obstructs engagement of the head, may cause the lie to be transverse and need a C-section
Haemorrhage postpartum can be severe as lower uterus less able to contract
Symptoms of placenta praevia
Intermittent painless bleeds increasing in frequency and intensity over weeks
1/3 experience no bleeding
Sign on examination of placenta praevia
Head not engaged - breech or transverse
What examination is never performed if placenta praevia suspected
PV exam - can provoke haemorrhage
Management of placenta praevia
Admit if bleeding - give anti D if Rh negative
If asymptomatic admit when 37 weeks
Deliver by C-section at 39 weeks
What is placenta accreta?
Placenta implanted too deep in the uterine wall - attaches to the myometrium instead of just the endometrium. Often over a C-section scar
What is placenta increta?
Placenta implanted deeper in the uterine wall and penetrates the myometrium
What is placenta percreta?
Placenta implanted so deep it penetrates through the uterine wall myometrium and possibly invades other organs such as the bladder
What is the risk of placenta accreta/increta/percreta? (3)
Massive haemorrhage at C-section
Damage to other organs
Thromboembolism
What is placental abruption?
When part or all of the placenta separated from uterus before delivery of the foetus
Complications of placental abruption (3)
Bleeding
30% foetal mortality
Maternal DIC and renal failure
Risk factors for placental abruption (8)
IUGR Pre-eclampsia Autoimmune disorders Smoking/drugs Previous abruption Multiple pregnancy High parity Trauma
Symptoms of placental abruption (5)
Shock Severe pain/tenderness May be dark blood or no bleeding Hard woody uterus Foetal head often engaged but distressed
What is a concealed abruption?
Just pain, bleeding not escaped uterus
Treatment of placental abruption (6)
CTG foetal monitoring and USS
Fluids, transfusion for mother
steroids if <34 weeks
Urgent C-section if foetal distress
Induce labour if >37 weeks and no distress
If <37 weeks and no distress, monitor as high risk
What is vasa praevia?
When a foetal blood vessel runs in the membranes in front of the presenting part - rare and hard to detect
Risk of vasa praevia
If membranes and vessels rupture, massive painless bleeding and severe foetal distress
Symptoms of vasa praevia
Typically painless moderate bleeding
Management of vasa praevia
Elective C-section
Often not quick enough if emergency after rupture and foetus exsanguinates
What is gestational trophoblastic disease
When trophoblastic tissue proloferates more aggressively than usual and hCG is secreted in excess
What is a hydatiform mole
Local non invasive proliferation of trophoblastic tissue
What is complete and incomplete hydatiform mole
Complete - paternal in origin, sperm fertilises empty oocyte and no foetal tissue present
Incomplete - two sperms fertilise on egg, variable foetal tissue
Complications of GTD
May have malignant characteristics - invasive mole, choriocarcinoma if any tissue left behind after the usual miscarriage
Symptoms of GTD (4)
Large uterus
Early pre-eclampsia
Vaginal bleeding
Vomiting
Investigations of GTD
‘snowstorm’ appearance of complete mole
confirmed histologically
Treatment of GTD
Tissue removed by evacuation of retained products of conception - suction curettage
If persistent high hCG, suggests malignancy
Chemotherapy and methotrexate
What is rhesus disease?
A type of haemolytic disease of the newborn, typically occurring in subsequent pregnancies of a Rh negative woman with a Rh positive father
Mechanism of rhesus disease
During a first pregnancy and birth, the woman is exposed to fetal blood
Rhesus negative woman develops antibodies against Rhesus D if the foetus is rhesus positive
In subsequent pregnancies, the antibodies can pass through the placenta and attack the fetal RBC in rapid immune response
Causing fetal anaemia and possible death
What are some sensitising events in rhesus disease? (6)
Birth Termination of pregnancy ERPC after miscarriage Ectopic pregnancy Early or heavy bleeding Invasive uterine procedure
Prevention of rhesus disease
Administed anti-D antibodies to the mother to prevent her immune system producing its own anti-D - the administered version will bind to fetal RBCs entering her bloodstream and prevent maternal recognition
When is anti-D administered?
To all Rh-ve women at 28 weeks
At all sensitising events
Kleihauer-Bletke test can be used to see how much fetal blood has crossed and thus dose of anti-D
Management of rhesus disease
Assess severity of foetal condition by MCA Doppler and foetal blood sampling
If anaemia, antenatal blood transfer
Deliver if >36 weeks
What causes gestational diabetes?
Decreased glucose tolerance in pregnancy due to altered carbohydrate metabolism and antagonistic effects of pregnancy hormones
Risk factors of gestational diabetes (6)
Family history PCOS Previous large or stillborn baby High BMI Glycosuria Polyhydramnios
Foetal complications of gestational diabetes (4)
Congenital abnormalities
Preterm labour
Birth trauma (shoulder dystocia)
Stillbirth
Maternal complications of gestational diabetes (7)
Increased insulin need Hypoglycaemia Worsening diabetes if pre-existing Pre-eclampsia Infection Instrumental/operative delivery Ketoacidosis
Treatment of gestational diabetes
Diet control
Metformin
Insulin
Delivery by 40 weeks
Treatment of gestational diabetes if pre-existing disease
Stabilise glucose before conception
Aspiring from 12 weeks to prevent pre-eclampsia
Tight insulin control
Induction or C-section by 39 weeks
Screening for gestational diabetes
Glucose tolerance test at 28 weeks
If previous history or RFs at 18 weeks
Define primary postpartum haemorrhage
Loss of >500mL of blood within 24 hours of delivery, or >1000mL after C-section - occurs in 10%
Causes of PPH (4)
Retained placenta
Uterine causes - failure to contract, from atony if prolonged labour or overdistension
Vaginal tear, episiotomy
DIC, anticoagulants
Risk factors of PPH (10)
Previous haemorrhage Previous C-section Coagulation defect or anticoagulants Instrumental or C-section Retained placenta APH Multiple pregnancy Multiparity Prolonged labour Induction
Prevention of PPH
Use of oxytocin (synctocinon) in 3rd stage of labour
Management of PPH (7)
RESUS
Remove retained placenta, identify any trauma
Bimanual compression of uterus
IV synctocinon or ergometrine to compress
Prostaglandin (carboprost) for uterine atony
Evac under anaesthetic if fails
Balloon tamponade surgery or artery embolisation
Hysterectomy last resort
Define secondary post partum haemorrhage
Excessive blood loss, occurs between 24hrs-6 weeks after birth
Causes of secondary post partum haemorrhage
Endometritis (with or without retained tissue)
Incidental pathology
Trophoblastic disease
Treatment of secondary post partum haemorrhage
Antibiotics
ERPC
What is preterm birth?
Delivery after 24 weeks and before 37 weeks. Occurs in 8% of deliveries and causes 20% of perinatal mortality
What are the categories of preterm birth?
Extremely premature <28 weeks
Very premature 28-32 weeks
Moderate to late preterm 32-37
Causes of preterm birth (8)
Subclinical infection Cervical incompetence Multiple pregnancy or polyhydramnios (overdistension) Antepartum haemorrhage Diabetes Foetal compromise Uterine abnormalities Prev. late miscarriage or premature birth Idiopathic/iatrogenic
Risks of preterm birth (6)
Causes 50% of cerebral palsy Foetal death Respiratory distress syndrome, pneumothorax Persistent pulmonary hypertension Intracranial haemorrhage Retinopathy of prematurity
Prevention of preterm birth (5)
Antibiotics if history of infection in preterm labour
Cervical suture at 12 weeks if incompetent cervix
Progesterone pessaries at 12 weeks or if cervix shortens
Foetal reduction of multiple pregnancy
Amnioreduction if polyhydramnios
Investigations for preterm birth (4)
Identify risk factors TVUSS for cervical length High vaginal swab for infection If symptomatic of labour, fetal fibronectin test - if negative, small chance she will deliver in next 2wks CTG for fetus
Management of preterm birth (4)
Steroids if <34 weeks
Antibiotics if confirmed labour only
Tocolysis (labour suppression) for 24hrs i.e. to give time for steroids
Magnesium sulphate for neuroprotection
How is slow labour defined?
Progress slower than 1cm/hour after the latent phase
How is prolonged labour defined?
> 12 hours active phase (after latent phase)
Causes of slow/prolonged labour (5)
Nulliparity
Inefficient uterine contractions
Large foetus
Disorder of fetal flexion or rotation during birth - MALPRESENTATION
Pelvic disproportion, cervical resistance
Management of slow/prolonged labour (6)
Supportive treatment
Mobilise
Amniotomy 1st line
Give oxytocin 2nd line if nulliparous, or if multiparous and malpresentation excluded
C-section if first stage
Instrumental then C section if needed if second stage
What are the 6 normal fetal movements in labour
1 - engagement in occipito-transverse
2 - descent and flexion
3 - rotation 90 degrees to occipito anterior
4 - descent
5 - extension to deliver
6 - restitution and delivery of shoulders
What is vertex presentation?
Maximal flexion - ideal presentation with occiput leading
What is brow presentation?
90 degree less flexion - forehead first, requires C-section mostly
What is face presentation?
120 degree less flexion - face first, fetal compromise common
Complications of occipito-posterior rotation position instead of occipito-anterior?
Facing up instead of towards mother’s rectum
Prolongs labour and causes more pain
Instrumental or C-section may be needed
Complications of failing to rotate from occipito-transverse position?
Requires ventouse delivery for rotation with traction to fi through pelvis
Normal lie and types of abnormal lie?
Normal - cephalic, head down Transverse Oblique Breech Abnormal lie normally rectifies itself later in pregnancy
Causes of abnormal lie - circumstances allowing more room to turn (2)
Polyhydramnios
Multiparity (laxer uterus)
Causes of abnormal lie - conditions preventing foetus turning (3)
Foetal abnormality
Multiple pregnancy
Anyhydramnios
Causes of abnormal lie - prevented engagement
Placenta praevia
Complications of abnormal lie (3)
Prevent delivery
Cause arm or cord prolapse
Uterine rupture
Management of abnormal lie
> 37 weeks admit and USS to identify cause
Try to manually turn fetus unless contraindicated and do amniotomy
C-section if persistent
What is breech presentation?
Buttocks are presenting part - can be extended, flexed or footling
Causes of breech presentation (5)
Previous breech Foetal or uterine abnormalities Twins Placenta praevia Pelvic deformity
Symptom of breech presentation
Upper abdominal pain, confirmed on USS
Complications of breech presentation (3)
Neurological problems i.e. cerebral palsy
Cord prolapse
Trapped head - quickly fatal
What is external cephalic version and when is it done?
Turning the fetus manually from outside pressure, success rate around 50%
Tried after 37 weeks
Management of breech birth
ECV
C-section if unsuccessful
90% of vaginal births are successful if breech, but C-section overall safer
When is external cephalic version not performed? (4)
Twins
APH
Ruptured membranes
Foetal compromise
What is preterm prelabour rupture of membranes?
Membranes rupture before labour at less than 37 weeks, occurs before 1/3 of preterm deliveries
Complications of preterm prelabour rupture of membranes? (4)
Preterm delivery - occurs within 48hrs in >50%
Infection - chorioamnionitis
Cord prolapse
Pulmonary hypoplasia if before 24 weeks
Symptoms of preterm prelabour rupture of membranes? (2)
Gush of clear fluid then leaking
Pain, fever, tachycardia, offensive liquor if chorioamnionitis
Investigations fo preterm prelabour rupture of membranes? (3)
US for reduced liquor
High vaginal swab, FBC for infection
CTG for fetus
Management of preterm prelabour rupture of membranes? (4)
Risk of preterm vs risk of infection! Admit and give steroids Prophylactic antibiotics Close surveillance Induction at 34-6 weeks if not already had baby
Management of chorioamnionitis?
IV Abx and delivery!
Prevention of preterm labour?
Cervical cerclage to strengthen cervix and keep it shut, if history of preterm birth or evidence of incompetent cervix on USS
Rescue suture if dilated cervix but no ROM or labour
What is prelabour term rupture of membranes?
Rupture of membranes after 37 weeks
Management of prelabour term rupture of membranes?
Wait for spontaneous labour (80% in 24hr)
Fetal CTG
Antibiotics if over 24hr prophylactically
Induce
What is uterine rupture?
Tear in the uterine muscle wall, spontaneously or at the site of an old c section scar
Complications of uterine rupture (4)
Extruded fetus
Contracting bleeding uterus
Maternal haemorrhage
Fetal hypoxia, death
Symptoms of uterine rupture? (5)
Fetal heart rate abnormalities Lower abdominal pain Vaginal bleeding Maternal collapse Cessation of contracttions
Causes of uterine rupture? (3)
Scarred uterus in labour
Neglected obstructed labour
Congenital uterine abnormalities
Management of uterine rupture? (4)
Avoid induction and oxytocin in scarred patients
Resuscitation
Urgent c section and repair uterus
C section for subsequent pregnancies
What is the cervical show?
Mucus plug that seals cervical canal during pregnancy to protect against infection, may have a bloody tinge,discharges when cervix starts to dilate
What bacterium is usually responsible for puerperal sepsis?
Group A streptococcus (strep pyogenes)
Risk factors for puerperal sepsis?
PROM
Prolonged labour
Multiple examinations
Manual removal of placenta
Treatment of puerperal sepsis?
Broad spec Abx - clindamycin, gentamicin
Why does risk of venous thromboembolism increase during pregnancy?
Blood clotting factors increased
Fibrinolysis reduced
Blood flow altered - obstruction, immobility
Most common site of DVT in pregnancy?
Left iliofemoral
How is VTE in pregnancy treated? (4)
SC low molecular weight heparin continued into puerperium if high risk
Mobilisation
Fluids
Compression stockings
Why is anaemia common in pregnancy?
40% increase in blood volume is greater then increase in red cell mass
Resulting fall in Hb concentration
Iron and folic acid requirements increase
Management of anaemia in pregnancy
Oral iron
Folic acid and B12
Prophylaxis if high risk
Why is UTI in pregnancy a problem?
Associated with preterm labour, anaemia, increased perinatal morbidity and mortality
Asymptomatic bacteriuria more likely to progress to pyelonephritis in pregnancy
Management of UTI in pregnancy?
Bacteriuria cultured at booking and treated
Routine urinalysis - culture if nitrites high
Erythromycin, nitrofurantoin
Symptoms of pyelonephritis?
Loin pain
Rigors
Vomiting
Fever
Most common causative organism of UTI in pregnancy?
E.coli
Treatment of pyelonephritis in pregnancy?
IV Abx (poss. ceftriaxone)
What is cephalo-pelvic disproportion?
The pelvis is too small to allow passage of the baby’s head
How is cephalo-pelvic disproportion diagnosed?
Mostly retrospectively, inability to deliver despite presence of adequate uterine activity and absence of malpresentation
What is inefficient uterine action and when is is more common?
Most common cause of slow progress in labour, common in nulliparous women and in induced labour
Treatment of inefficient uterine action? (3)
Amniotomy
Oxytocin if fails
C section if fails
What is obstructed labour?
Failure to progress in labour with normal contractions due to physical block - >12 hours active labour
Causes of obstructed labour? (4)
Large baby
Malpresentation
Small/deformed pelvis
Narrow vagina/peritoneum factors (FGM)
Complications of obstructed labour? (5)
Hypoxia and fetal death Infection Uterine rupture PPH Obstetric fistula
Management of obstructed labour? (3)
C section
Ventouse extraction
Possible widening of symphysis pubis surgically
What is cord prolapse and what can it cause?
When the umbilical cord prolapses into the cervix when after rupture of membranes, can cause fetal asphyxia and uterine rupture
Risk factors for cord prolapse?
Twins
Footling breech
Shoulder presentation
Management of cord prolapse? (6)
If thought to be a risk before ROM, C section
Displace presenting part by pushing it up but do not handle cord
Place woman head down so gravity relieves pressure
Bladder infusion via catheter
Deliver by forceps/vaginally QUICKLY if imminent delivery
If not usually deliver by C section
Types of instrumental delivery?
Ventouse, forceps (non rotational and rotational)
When is instrumental delivery indicated? (4)
Prolonged second stage of labour - if 1hr of active pushing has failed to deliver
Fetal distress
Breech delivery
If maternal pushing contraindicated i.e. hypertension
Complications of instrumental delivery?
Maternal trauma - lacerations, haemorrhage, tears
Fetal trauma - lacerations, bruising, facial nerve injury, hypoxia
What is the common c section?
Lower segment (LSCS)
Indications for C section? (5)
Breech Previous LSCS Placenta praevia Failure to advance Fetal distress
Complications of C section? (5)
Haemorrhage Infection VTE Anaesthetic risk Risk of uterine rupture in subsequent pregnancies
What is polyhydramnios?
Increased liquor volume - deepest pool >10cm abnormal
Cause of polyhydramnios? (3)
Gestational diabetes, renal failure
Twins
Fetal anomaly - upper GI, inability to swallow, chest abnormalities, myotonic dystrophy
Presentation of polyhydramnios (4)
Maternal discomfort
Large for dates
Taut uterus
Difficult palpation
Management of polyhydramnios? (5)
USS for anomaly Blood glucose screening for GD If <34 weeks and severe, amnioreduction or use NSAIDs to reduce fetal urine output If <34 weeks consider steroids Vaginal delivery
Complications of polyhydramnios?
Preterm labour
Maternal discomfort
Malpresentation
What is oligohydramnios?
Reduced liquor volume, non specific, more common in compromised fetuses
Cause of oligohydramnios? (4)
Preterm rupture of membranes
Placental insufficiency
Renal agenesis or multicystic dysplastic kidneys
Chromosomal abnormality
Management of olighydramnios?
if PROM, manage as preterm or term PROM
Monitor fetus, deliver when distressed but optimal gestation
What are dizygotic twins?
Most common type
Result from fertilisation of different oocytes by different sperm, not identical
What are monozygotic twins?
Result from mitotic division of a single zygote into identical twins, sharing of the amnion and placenta depends on when they divided
What are dichorionic diamniotic MZ twins?
Division of the zygote before day 3, leads to separate placentas and amnions
What are monochorionic diamniotic MZ twins?
Division of the zygote between days 4-8 (most common), leads to shared placenta but different amnions
What are monochorionic monoamniotic MZ twins?
Division of the zygote between days 9-13, very rare, leads to a shared placenta and amnion
How do conjoined twins occur?
Incomplete division of the zygote
Cause of twins? (5)
Genetics Assisted conception - multiple embryo transfer in IVF Clomifene Increased age Increased parity
Maternal complications of twins? (3)
Gestational diabetes
Pre-eclampsia
Anaemia
Fetal complications of twins? (4)
Placental insufficiency and IUGR Preterm birth Malpresentation Miscarriage - co-twin death Congenital abnormalities (MC)
Complications of monochorionicity? (MCDA and MCMA)
Twin to twin transfusion syndrome
IUGR
Co-twin death
Cord entanglement in MCMA
What is twin to twin transfusion syndrome?
Only occurs in MCDA twins
Results from unequal blood distribution through vascular anastomoses of the shared placenta
Symptoms of TTTS?
Donor: oligohydramnios, anaemia, IUGR
Recipient: polyhydramnios, polycythaemia, cardiac failure
Complications of TTTS?
Massive distended uterus
Preterm birth
In utero death
Fetal neurological damage
Management of TTTS?
US monitoring from 12 weeks
Laster therapy of the placental anastomoses
Management of twin pregnancy? (6)
Increased surveillance
Laser treatment if TTTS
Deliver: 34-37 weeks if MC, 37-38 weeks if DC
C section if first twin not cephalic
If vaginal, ECV for second twin if not cephalic
Amniotomy when 2nd twin engaged
What is Bishop’s score sued for?
Used to determine favourability/ripening of the cervix, if high score cervix is favourable and induction more likely to succeed
What is Bishop’s scoring system parameters (5)
Dilation of cervix (0->5cm) Consistency of cervix (firm-soft) Length of cervical canal (>2-<0.5) Position of cervix (posterior-anterior) Station of presenting part (-3 to below spines)
What is hyperemesis gravidarum?
Pregnancy complication characterised by severe nausea, vomiting, weight loss, dehydration
Management of hyperemesis gravidarum? (4)
Exclude UTI, hydatiform mole
IV fluids
Antiemetics - metoclopramide
Thiamine
What is the partogram?
Used to record progress in dilatation of the cervix, +/- descent of the head
How is the partogram completed?
Vaginal examination to assess cervical dilatation, plotted against time
Purpose of the partogram?
To aid identification of abnormal progress through labour (i.e. slower than 1cm/h after the latent 0-3cm phase) and record maternal vital signs
What is cardiotocography?
Records the fetal heart rate on paper from a transucer placed on the abdomen or a clip in the vagina attached to the fetal scalp
A second transducer monitors contractions
Worrying features on CTG? (5)
Steep, sustained deterioration in HR
Reduced variability <5bpm
Variable decelerations
Late decelerations (persisting after contractions)
What should FHR be on CTG?
110-160
What is fetal scalp sampling?
Amnioscope inserted vaginally, small cut made in scalp which collects blood, pH analysed
What is a worrying pH on scalp sampling and how is it managed?
<7.2
Delivery expedited
What is induced labour?
Labour started artificially
When is labour induced? (6)
Prolonged pregnancy Suspected IUGR Fetal compromise Prelabour term rupture of membranes Pre-eclampsia APH/poor obstetric history
Contraindications to induction? (4)
Acute fetal compromise
Abnormal lie
Placenta praevia
Pelvic obstruction
How is labour induced? (3)
Prostaglandin E2 gel into the vagina - starts labour or improves cervical ripening for amniotomy
Can give 2 doses
Amniotomy rupture of membrane
Oxytocin infusion
Indications fo C section? (5)
Acute fetal distress Failure to progress - indications for instrumental not met i.e. not fully dilated Placenta praevia Breech Previous LSCS
Difference between small for dates and IUGR?
SFD weight less than 10th centile
IUGR fail to reach individual growth potential
What is doppler umbilical artery monitoring and what is it used for?
Doppler used to measure velocity wave forms in the umbilical arteries
Can identify IUGR and compromise
What is abnormal umbilical artery waveforms?
Reduced flow in fetal diastole compared to systole
Suggests placental dysfunction, high resistance circulation
What is doppler waveforms of the fetal circulation?
Commonly measures the middle cerebral artery and ductus venosus
What are abnormal fetal circulation waveforms?
MCA develops low resistance compared to rest of body, head sparing
Velocity of flow increases
Suggestive of fetal anaemia
What is amniocentesis?
Diagnostic test that removes amniotic fluid using a needle under US guidance- after 15 weeks
What is amniocentesis used for? (3)
Prenatal diagnosis of chromosomal abnormalities, sickle cell anaemia, CMV
Risks of amniocentesis? (4)
Miscarriage 1%
Fetal injury
Rhesus sensitisation
Chorioamnionitis
What is chorionic villus sampling?
Diagnostic test involving biopsy of the trophoblast using a needle - after 11 weeks
What is chorionic villus sampling used for?
Earlier result than amniocentesis - abortion easier
Used to diagnose chromosomal problems and autosomal dominant and recessive conditoins
What are the increased risks of chorionic villus sampling?
Miscarriage (more than amniocentesis)
What are the mechanisms used to obtain results in amniocentesis and CVS?
Fluorescent in situ hybridisation FISH
Polymerase chain reaction PCR
What are the 5 things checked for in APGAR scoring?
Activity (muscle tone) Pulse Grimace (reflex irritability) Appearance (colour) Respiration Higher score the better
What are the stages or preimplantation development?
2 cell stage 4 cell stage 8 cell stage Morula Blastocyst Hatched blastocyst
What are the components of the blastocyst?
Trophectoderm (outer layer)
Inner cell mass
Blastocoele cavity
What are 3 essential factors for embryo implantation?
Receptive endometrium
Healthy blastocyst
Communication between mother and baby
What is fertilisation?
Fusion of gametes (egg and sperm) to form a zygote and initiate development
What is capacitation?
Changes in the sperm that occur in the female tract to increase motility and prepare the membrane for acrosome reaction
What is the zona pellucida?
Outer layer of the egg, containing glycoproteins that trigger the acrosome to burst and release enzymes to break down the ZP
What is the cortical reaction?
Sperm has entered the centre of the egg and cortical granules fuse with the membrane of the egg to harden the ZP and make it impermeable to further sperm
How is a zygote formed?
The oocyte undergoes a second meiotic division to become haploid
The sperm and ovum nucleus fuse and membranes dissolve, creating diploid zygote
How is a blastocyst formed from a zygote?
Mitotic cell division - cleavage
Morula (16 blastomeres) compacts - forms hollow ball of inner cell mass and trophoblast -and forms blastocyst by day 5 when enters uterus
How does blastocyst implant?
Hatches from the zona pellucida
Implants in endometrium with the trophoblast
