Obs Flashcards
(32 cards)
What are the classifications of placenta accreta spectrum?
Placenta accreta – invasion of placenta beyond decidua basalis, not into myometrium
Placenta increta – invasion of placenta beyond endometrium into myometrium
Placenta percreta – invasion of placenta into serosa +/- invasion into surrounding organs e.g. bladder
What are risk factors for placenta accreta spectrum?
Previous CS (RR 4.5, >/= 4CS RR 45) Previous uterine surgery - STOP, MROP, Curette, Previous accreta Previous placenta praevia AMA Multiparity Smoking ART
Name 11 USS features of placenta accreta
- Loss of hypo-echoic retroplacental clear zone
- Placental lacunae
- Abnormal myometrial/bladder interface
- Thinning <1mm or absence of myometrium beneath placenta
- Focal bulge of serosa
- Exophytic mass
- Hypervascularity between uterus/bladder
- Subplacental hypervascularity
- Bridging vessels from placenta across myometrium
- Placental lacunae feeding vessels
- Parametrial involvement
Management of placenta accreta spectrum
High level of diagnostic suspicion
MDT with tertiary centre input
Stay near to centre
Hb optimisation
MRI for operative planning - NOT diagnosis
Planned early delivery by caesarean section - RANZCOG does not given definite time (RCOG says 35-36+6). Alter if RFs for preterm birth.
Consider antenatal corticosteroids
Consent ahead of time including need for RBC transfusion, hysterectomy, higher risk renal tract injury
Have valid G&H, be prepared to activate MTP
Consider usage of cell saver
Aim regional anaesthesia - consider CSE
Delivery options
- CS, lower segment, attempt delivery of placenta, prepare for hysterectomy if not
- CS with incision away from placenta, delivery, closure of uterotomy and hysterectomy
- CS with incision away from placenta, delivery, trim short placenta cord and closure. Manage conservatively and/or plan hysterectomy at a later date
- CS with incision away from placenta, delivery, partial resection of uterine wall and repair
Conservative treatment - HIGH risk of infection, later emergency hysterectomy
Avoid ecbolic if not planning to separate placenta
Consider ureteric stents if percreta involving bladder, not routinely
What is the differential diagnosis for fetal hydrops?
Fetal anaemia - Immune haemolytic disease - parvovirus - FMH - Alpha thalassaemia - HbH Fetal infection - CMV - Toxoplasmosis - Syphilis - Parvovirus (as aboev) Fetal cardiac anomaly Metabolic Aneuploidy e.g. Turner's syndrome TTTS Fetal chylothorax Idopathic
What are classes of obesity in pregnancy?
Obese Class I BMI 30-34.9
Obese Class II BMI 35-39.9
Obese Class III BMI >40
List complications associated with obesity in pregnancy
Fertility delay
Miscarriage
Fetal anomaly, neural tube defects
Excessive gestational weight gain
Gestational diabetes
Fetal macrosomia
Pregnancy induced hypertension and pre-eclampsia
Undetected intrauterine growth restriction - Limited fundal palpations – more reliant on USS for fetal growth surveillance
Preterm birth
Stillbirth
Venous thromboembolism
Labour dystocia
Shoulder dystocia
Post partum haemorrhage
Assisted vaginal birth
Caesarean section and emergency caesarean (and associated complications all higher – bleeding, infection, injury to viscera)
If obesity hypoventilation and sleep apnoea – chronic intrauterine hypoxia
More complicated anaesthesia – epidural and spinal difficult insertion, higher rate of aspiration with GA
Higher ICU admission
Lower breastfeeding
Infant more likely to become obese
Higher rate of maternal death
Higher obstructive sleep apnoea
What are the benefits of IOL before 39weeks for suspected fetal macrosomia?
Less shoulder dystocia - RR 0.6
Less boney fracture - RR 0.2, NNT 60
No change in CS birth
No change in assisted vaginal birth
BUT
No significant differences in brachial plexus injury (although very infrequent finding)
What are recommended measures to prevent fetal macrosomia?
Regular exercise - aerobic and strengthening, as long as not contra-indicated
Maintenance of near-normal BSLs in diabetic mothers
Pre-pregnancy weight optimisation, recommend discussion re bariatric surgery if class III obesity
What is the definition of GDM?
Evidence of impaired glucose tolerance first diagnosed or developed in pregnancy
What are the WHO 10 steps of breastfeeding?
- Have a written policy
- Train staff to have skills to implement policy
- Inform women about benefits
- Help mothers breastfeed within 30mins of birth
- Show mothers how to breastfeed and how to maintain this
- Don’t offer any alternatives unless indicated
- Practise rooming in
- Encourage breastfeeding on demand
- Give no artificial teats or pacifiers
- Foster support groups and refer mothers to them
What are advantages to breastfeeding?
Neonatal/paediatric:
↓ Reflux, respiratory illness, otitis media, SIDS, atopy, UTIs, T1 and T2DM, obesity
Effective pain relief for minor procedures
Maternal: ↓ ovarian and breast ca risk ↓ PPH as involutes faster Lower cost Provides amenorrhoea and contraception ↑ bonding
How are preterm births classified?
Gestation Classification Frequency
34-36 weeks Late preterm 32-36weeks 84% preterm births
32-34+ weeks Moderate preterm <34weeks 3% all births Aus
28-32weeks Very preterm 10% preterm births, <32weeks 1.2% all births NZ
<28weeks Extremely preterm 5% preterm births, 0.5% all births in NZ
What is the definition of a live birth?
Expulsion from the mother at any gestation and after separation shows signs of life - breathing, heart beating, definite movement of voluntary muscle, cord pulsating
What is the definition of a miscarriage?
Loss of a pregnancy <20weeks
What is the definition of a stillbirth?
Birth of a baby with no signs of life >/= 20weeks gestation or >/= 400g if gestation unknown
What is the definition of neonatal mortality?
Death of a live-born baby from birth until midnight on 27th day of life
What is the definition of perinatal mortality?
What is the rate in Aus/NZ?
Any loss of life from 20weeks until midnight 27th day of life (stillbirth and neonatal mortality)
(NZ go until midnight on 6th day of life)
Rate is per 1000 births
NZ 10/1000 = 1%
Australia 9.6/1000
How is maternal morbidity defined?
Any short- or long-term outcome that results from pregnancy or birth with negative outcome on woman’s wellbeing
Benefits of early epidural in women with PET
Reduces pre and afterload - BP treatment in labour
Adequate analgesia
Avoids fluctuations in BP if GA and intubation needed - also airway oedema so GA higher risk
Quicker block if OT needed in a hurry
May also improve renal and placental flow
MSS1
Combined FTS 11+0 - 13+6/40
Serum - PAPP-A, BhCG
USS - NT if >3mm higher assoc with aneuploidy
Provides risk assessment for T21, T13, T18
Sensitivity 85%
Specificity 95%
PPV depends on maternal age - higher if >35y (as higher prevalence in this population)
Benefits:
Non-invasive - no miscarriage risk from the test
Screen at relatively early gestation, if leads to TOP earlier gestation makes safer
Biomarkers provide risk for IUGR, PET
Early USS - may show up to 50% of major anomalies, identify multiple pregnancy, confirm gestation, diagnose missed miscarriage
Performs well in an at-risk population
More accurate than MSS2
Disadvantages:
Resource dependent - bloods and skilled ultrasonographer
Time critical - some may not have booked yet
Detection of affected pregnancy that may have gone on to spontaneously miscarry (15% of T21 at 11-16weeks)
False positive may cause high anxiety, may affect screening participation in a future pregnancy
Need for invasive test to confirm - risks associated with this, potential for normal pregnancy to miscarry
Costs to the patient may vary
MSS2
Second trimester 15-20weeks
Serum - BhCG, AFP, Oestradiol, Inhibin A
Sensitivity 75%
Specificity 95%
PPV 3%
Benefits:
Non invasive
Easy to perform as single blood test
Suitable screening if pregnancy diagnosed/booked late
Performs better in a higher risk population
Biomarkers e.g. AFP can also provide a clue of other structural abnormalities if very high e.g. NTD
Disadvantages:
Less accurate than MSS1
Later gestation, if truely abnormal and TOP planned this may be getting close to viability
Not suitable for multiples as biomarkers confound
Biomarkers affected by other factors - IVF, weight, smoking
Relies on invasive test to confirm - could lead to healthy pregnancy miscarrying
Does not provide structural assessment of baby, confirm gestation, viability, multiple or not
T21
1: 400 pregnancies
1: 1000 livebirths
Increasing maternal age is biggest predictor
1: 1000 at term if 30
1: 300 at term if 35
1: 100 at term if 40
Biomarkers: Low PAPP-A High BhCG Low inhibin-A Low oestradiol
Features:
Wide nasal bridge, epicanthal folds, brachycephaly, webbed neck, upward slanting eyes, single palmar crease
Complications:
Cardiac defects, duodenal atresia, epilepsy, dementia, hypothyroidism, leukaemia, immune deficiency, intellectual impairment
Recurrence risk 1:100
Parvovirus
Single stranded DNA virus
Transmitted respiratory secretions, hand to mouth
Targets P antigen on fetal RBCs and erythrocyte precursors. Leads to haemolytic anaemia and sometimes hydrops, fetal death.
Higher risks are infection <20weeks as erythropoiesis in liver and at most rapid.
50% risk fetal infection
- asymptomatic - most likely
- fetal anaemia - usually self limited
- fetal hydrops ~3%, average onset 5weeks post infection
- miscarriage 10% extra if <20weeks
Management:
Counsel about exposure risks
Offer serological testing (IgM, IgG +/- avidity)
No specific intervention to prevent or treat
Do not offer TOP - risk of adverse fetal outcome is low
USS 1-2weekly for 12 weeks - MCA PSV (>1.5MoM suggests anaemia), hydrops
Refer to FMed if signs of anaemia/hydrops - fetal blood sampling +/- IUT
FMed to confirm fetal infection if signs – Amnio and PCR (not if normal USS)
Normal cares if no anaemia - no evidence of longterm sequalae
Prevention
No vaccine
Hand hygiene
No need to stay at home in pandemic
