Pregnancy Complications Flashcards
What is placental abruption?
Separation of part or all of the decidua basalis from the uterine wall
What happens in placental abruption?
Rupture of maternal vessels within basal layer of endometrium. Blood accumulate and split placental attachment from basal layer. Detached portion of placenta unable to function –> fetal compromise
What are the types of placental abruption?
Revealed (80%)
Concealed (20%)
What is a revealed placental abruption?
Bleeding tracks down from site of placental separation
Drain through cervix resulting in vaginal bleeding
What is concealed placental abruption?
Bleeding collects between the uterus and the placenta. A retroplacental clot forms
Bleeding not visible but can cause systemic shock
How common is placental abruption and when does it normally happen?
1/200 pregnancies
Usually happen >20 week gestation
How is placental abruption diagnosed?
Clinical diagnosis based on:
Tense tender uterus with “woody” feel on examination
USS - clot may not be easily distinguishable
CTG abnormalities - foetal distress
Platelet count may be low
Coag screen - coagulopathy common
How does placental abruption present?
Painful vaginal bleeding
Pain between contractions (if in labour)
Uterus tense all the time
Shock out of proportion to blood loss - if concealed
What are the key risk factors for placental abruption?
Previous Hx of abruption Hypertension and smoking - diseased vessels Abdominal trauma Abnormal lie of baby Polyhydramnios Multiple pregnancy
How can placental abruption be managed?
Emergency C Section - if maternal or foetal compromise
Induction of labour - if haemorrhage at term without maternal or foetal compromise
Conservative - for partial or marginal abruptions without compromise
In all cases - give anti-D within 72hrs of onset if Rhesus D -ve
What is placenta praevia?
Placenta lie partially or wholly in lower uterine segment in front of the presenting part of the foetus
Usually happen >20 weeks gestation
How is placenta praevia graded?
1: low lying
2: reaches the internal os
3: covers the os when not dilated but on dilation it no longer covers the os
4: covers the os symmetrically
How common is placenta praevia?
5% low lying placenta at 16-20 week scan
Incidence at delivery only 0.5% - most rise away from cervix
What are the main risk factors for placenta praevia?
Previous hx
Previous caesarian - implant on scar
Multiple pregnancy
Advancing maternal age
How does placenta praevia present?
Picked up on routine 20 week scan
Painless vaginal bleeding - vary from spotting to haemorrhage
Lie and presentation may be abnormal
If a placenta praevia minor is picked up at a 20 week scan, what should happen?
Repeat scan at 36 weeks
Placenta likely to have moved superiorly in this time
If a placenta praevia major is picked up at a 20 week scan, what should happen?
Repeat scan at 32 weeks
Plan for delivery made at this time
What is the safest mode of delivery for confirmed placenta praevia?
C Section
Electively done at 37 weeks if placenta praevia major
What complications are associated with placenta praevia?
Pre-term delivery
Hypovolaemic shock
Placenta accreta
Fetal hypoxia and asphyxia
What must not be done if a patient has placenta praevia?
Vaginal exam
May start torrential bleeding
What is the difference in how placenta praevia and placental abruption present?
Placenta Praevia - painless, bright red blood, proportional blood loss to shock, no associated conditions
Placental abruption - painful, bleeding can be concealed, dark coloured, shock out of proportion to blood loss, associated with preeclampsia
What is the difference between placenta praevia and placental abruption on abdominal examination?
PP - Uterus size normal, soft and relaxed, fetus malpresentation common, Fetal heart sounds usually present
PA - Large for date tender, rigid uterus, fetal presentation unrelated, fetal heart sounds usually absent
What is the difference between placenta praevia and placental abruption on placentography and vaginal exam?
PP - Placenta in lower segment and palpable there in vaginal exam
PA - Placenta in upper segment and not palpable on vaginal exam
What is placenta accreta?
Attachment of the placenta to the myometrium due to defective decider basalis
Doesn’t separate in labour
What are the types of placenta accreta?
Accreta - Chorionic villi attach to myometrium rather than being restricted within decidua basalis
Increta - Chorionic villi invade into myometrium
Percreta - Chorionic villi invade all the way through to the perimetrium
What are the risk factors for placenta accreta?
Previous C Section
Placenta praevia
How can placenta accreta be diagnosed?
Imaging can raise suspicion
Definitive diagnosis through surgery
What are complications associated with placenta accreta?
Preterm delivery
Retained placenta and PPH
What should be done if you suspect placenta accreta?
Consultant obstetrician and anaesthetist at birth with blood
Uterus opened at site distant to placenta so baby can be delivered without disturbing it
What is done if placenta accreta is confirmed?
Hysterectomy
What does conservative management of placenta accreta involve?
Leave placenta in place
Uterine artery embolisation
Plan elective hysterectomy
What is rhesus isoimmunisation?
Production of antibodies in response to an isoantigen present on an erythrocyte
What happens in rhesus isoimmunisation and why is it dangerous?
Maternal antibodies formed in response to surface antigen on fetal RBC in sensitising event
Primary exposure - rarely any adverse effect
Secondary exposure - further pregnancies - maternal antibodies cross placenta and attack fetal RBC’s (if same surface antigen) –> haemolysis and fetal anaemia
Give an example of how you could get haemolytic disease of newborn
Mother Rhesus -ve, Father rhesus +ve
1st pregnancy - Rhesus +ve and sensitising event
2nd pregnancy - Rhesus +ve, maternal antibodies cross and attack fetal Rh+ve RBC’s
Haemolysis
What are some causes of sensitising events?
Invasive obstetric testing - chorionic villi sampling, amniocentesis Antepartum haemorrhage >12 weeks Ectopic pregnancy External cephalic version Fall/trauma Intrauterine death Miscarriage >12 weeks Termination of pregnancy Delivery
What investigations are done following a sensitising event?
Maternal blood group - find out ABO and Rhesus
Maternal antibody screen - detects antibodies against RBC surface antigens
Fetal maternal haemorrhage test - Kleihauers test
What is kleihauers test? When is it used? What is it used for?
Assess how much fetal blood has entered maternal circulation
if sensitising event >20 week gestation
Used to determine how much AntiD immunoglobulin should be given
How are women managed following a sensitising event?
Anti-D immunoglobulin administered - bind to maternal Rh+ cells - no immune response
How is rhesus isoimmunisation screened in the UK?
What then happens if they are -ve?
All pregnant women have blood group and antibody test at booking visit (8-12 weeks) and again at 28 weeks
Any Rhesus -ve woman is offered anti D prophylaxis at 28 and 32 weeks
When is a pregnancy considered prolonged?
> 42 weeks gestation
What are the risk factors for prolonged pregnancy?
Nullparity
Maternal age >40
High BMI
Previous prolonged pregnancy
How can prolonged pregnancy present?
Macrosomia Oligohydramnios Reduced fetal movements Meconium staining - on fingernails Reduced vernix and dry skin Reduced subcutaneous fat
What complications are associated with prolonged pregnancy?
Still birth - exponential rise from 37 weeks on
Macrosomia complications - shoulder dystocia, perineal tears, obstructed labour
Placental insufficiency and degradation = distress
- IUGR
- meconium aspiration
- hypoglycaemia
- acidosis
What can placental insufficiency lead to?
Fetal acidaemia Distress = meconium aspiration IUGR features Reduced O2 and nutrient transfer Neonatal hypoglycaemia
What are the maternal complications associated with prolonged pregnancy?
Perineal damage
Obstructed labour
Need for instrument or c section
How are prolonged pregnancies managed?
Membrane sweep - 40 weeks if nullparous, 41 weeks if multiparous
Induction of labour - between 41 and 42+0 weeks
- break water
- intravaginal prostaglandins
- oxytocin
What should be done if women decline management for prolonged labour?
2x weekly CTG
Amniotic fluid measurements - identify fetal distress
What is amniotic fluid made of?
Lung fluid
Fetal urine
Placental contributions
What happens to amniotic fluid?
Fetus breathe and swallow fluid - get processed and fill bladder where it is voided
How does the volume of amniotic fluid normally change? How much is left at term?
Increase steady until 33 weeks
Plateau 33-38 weeks
Decline until term to reach 500ml
How is amniotic fluid measured?
Amniotic fluid index - measure maximum cord free vertical pocket in each of 4 quadrants of uterus and add together
Maximum pool depth - vertical measurement in any are
How is oligohydramnios characterised?
Less than 500ml at 32-36 weeks
Amniotic fluid index <5th percentile
What can cause oligohydramnios?
Premature rupture of membranes Placental insufficiency Fetal renal problems - genesis, cystic Obstructive uropathy IUGR Post-term gestation Pre-eclampsia
How would you assess a patient with oligohydramnios?
Look for underlying cause: Leakage - new urinary incontinence Speculum examination - liquid in vagina IUGR signs - UAD Measure insulin like growth factor binding protein in vagina - suggest membrane rupture
How is polyhydramnios characterised?
Amniotic fluid index >95th percentile
What can cause Polyhydramnios?
Idiopathic - 50-60% Conditions that prevent fetal swallowing - oesophageal/duodenal atresia, CNS abnormalities, muscular dystrophy Twin-twin transfusion syndrome Maternal diabetes Maternal ingestion of lithium Macrosomia TORCH infections
What are the TORCH infections?
Perinatal infections
T - Toxoplasmosis O - Other - syphilis, varicella, parvovirus R - Rubella C - Cytomegalovirus H - Herpes
How is Polyhydramnios managed?
Amnioreduction
Indomethacin - enhance water retention so reduced fetal urine output
For idiopathic, baby must be examined before first feed - nasogastric tube passed to ensure no tracheoesphageal fistula or oesophageal atresia
What risks are associated with amnioreduction?
Infection
Placental abruption - sudden decrease in intrauterine pressure
What risks are associated with indomethacin?
Premature closure of ductus arteriosus - not used beyond 32 weeks
What symptoms do mothers with Polyhydramnios present with?
Breathlessness Swollen feet Indigestion Constipation Baby bump very large/heavy
What complications are associated with Polyhydramnios?
Pre-term labour - over distention of uterus
Malpresentation - fetus has more room to move
Cord prolapse
PPH - uterus has to contract down further
What are the types of twin pregnancy?
2 ova fertilised:
2 chorion and 2 amnion
Can have own or fused placenta
1 ova fertilised:
- Embryo split at 3 days - own placenta - 2 chorion, 2 amnion
- Embryo split at 4-7 days - 1 placenta - 1 chorion, 2 amnion
- Embryo split at 8-12 days - 1 placenta - 1 chorion and 1 amnion
Later - conjoint
How do twin pregnancies normally present?
Pick up on scanning in 1st trimester
Hyperemesis
Exaggerated pregnancy symptoms
Uterus palpable earlier than 12 weeks
How common are twin pregnancies in IVF?
24% of successful IVF
How are multiple pregnancies monitored?
Scan at 11-13 weeks - gestational age, chronicity, screen for down’s
Other scans depend on type of twinning but monitor:
- difference in fetal weight
- IUGR
What is twin-twin transfusion syndrome?
How is it managed?
Disproportionate blood supply between 2 twins leading to still birth and other complications
Laser treatment of the placental vascular anastomoses
What fetal risks are associated with multiple pregnancy?
Greater risk if placenta shared
- Miscarriage and still birth
- Preterm birth
- Down’s
- Umbilical cord entanglement
- IUGR
- Developmental and behavioural problems
- Feeding issues
When should multiple pregnancies be offered delivery?
Triplets - 35 weeks
Monochorionic - 36 weeks
Dichorionic - 37 weeks
What is the method of delivery for multiple pregnancy?
Vaginal as long as twin 1 cephalic C section if: - twin 1 breech - 1 amnion - other complications - triplets or more
What are the risks of multiple pregnancy for the mother?
Anaemia Pre-eclampsia Severe symptoms of pregnancy Extra load on heart Antepartum and Postpartum haemorrhage
What is fetal distress?
Compromise to the fetus due to reduced oxygen or nutrition
What are the signs of fetal distress?
Reduced fetal movements Abnormal non-stress test and/or contraction stress test Abnormal amniotic fluid Amnormal biophysical profile Vaginal bleeding Cramping Maternal hypertension Insufficient or excess maternal weight gain
What can cause fetal distress?
Uteroplacental insufficiency
- vascular disease
- intrauterine sepsis
- oligohydramnios
- reduced fetal reserves
- hypovolaemia
- IUGR
How is fetal distress managed?
Monitor - view for induction or C-Section
Balance risks of fetal distress and prematurity
If fetal distress continues in labour, what should happen?
Expedite delivery
< 30mins
What are the risks of smoking in pregnancy (including cannabis)?
Miscarriage Pre-term labour Stillbirth IUGR SIDS
What are the risks of alcohol in pregnancy?
Fetal alcohol syndrome:
- Learning difficulties
- Characteristic facies - smooth philtrum, thin vermilion, small palpebral fissures
- IUGR and postnatal restricted growth
- Microcephaly
What are the risks of cocaine in pregnancy?
Maternal - HTN, pre-eclampsia, placental abruption
Fetus - prematurity, neonatal abstinence
What is the main risk of heroin in pregnancy?
Neonatal abstinence syndrome
What prescription drugs can’t be taken in pregnancy?
Antibiotics - tetracyclines, aminoglycosides, sulphonamides, trimethoprim, quinolones
ACE inhibitors, ARB's Statins Warfarin Sulphonylureas Retinoids Cytotoxics
How does foetal anaemia present?
HF
fluid retention (liver devoted to RBC production so albumin reduced)
death
After birth: jaundice (placenta clears bilirubin in utero and at birth the liver can’t)
What can cause placental insufficiency?
Smoking HTN Diabetes Anaemia Maternal hypovolaemia
What are the results of placental insufficiency?
Fetal distress oligohydramnios IUGR Cerebral palsy due to reduced O2 Hypoglycaemia Placental vascular occlusion due to raised EPO Infections due to low WCC
How would you treat a UTI in pregnancy?
Can give nitrofurantoin in T1 and T2
Give cephalexin in T3
