Obs Flashcards
What are the causes of fetal hydrops?
Immune (10%) - anti-D antibodies etc
Non-immune (90%)
- cardiovascular (arrhythmias, congenital heart block/ anti-Ro/anti-La abs, myocarditis, structural abn)
- other malformations including cystic hygroma, diaphragmatic hernia etc
- aneuploidies
- haematological (thalassemia, chronic abruption)
- maternal diabetes, liver dysfunction
- infection (TORCH,esp parvovirus)
(Also TTTS)
CAUSTIC
Parvovirus:
IgM positive, IgG positive
Interpretation?
Recent infection
Parvovirus
IgM negative, IgG positive
Interpretation?
Immune
Parvovirus
IgM positive, IgG negative
Interpretation?
Possible recent infection, or false positive IgM
- repeat serology in 2-4 weeks
- if IgG then positive = recent infection
Features of congenital CMV on USS
Microcephaly, hydrocephalus, intracranial calcifications.
IUGR
Hepatomegaly, abdominal calcifications.
Hyperechogenic bowel
Hydrops.
Risk of transmission with primary CMV
vs
Non-primary
30%
vs
~1%
Risk of symptomatic congenital CMV with fetal transmission of primary CMV infection?
10-15%
What are the symptoms of congenital CMV infection?
Early mortality (1st 3/12) 5-10%
Neurological sx: Microcephaly (35-50%) seizures (10%) chorionitis (10-20%), NDD (<70%), cerebral palsy, psychomotor development.
Long term sequelae of congenital CMV
Sensorineural hearing loss
Visual loss (retinitis, cataracts)
Microcephaly
Developmental delay
Seizures
Cytomegalic inclusion disease
Cerebral palsy
How soon after chickenpox exposure should you give VZIG?
Ideally within 96 hours, but can be effective when given up to 10 days after
Risks of varicella in pregnant women?
Pneumonia
Hepatitis
Encephalitis
Increased mortality
What is the sensitivity and specificity of MSS1 for T21?
Sens 85%
Spec 95%
What is the sensitivity and specificity of MSS2 for T21?
Sens 75%
Spec 93%
What are the risks of CVS?
When can it be performed?
Miscarriage 0.5-1%
1-2% placental mosaicism
1% chance of incorrect diagnosis due to maternal contamination
Risk of limb defects if performed too soon
Maternal haemorrhage is rare
11+2 to 13+6
Risks of amniocentesis?
When can it be performed?
Risk of miscarriage of ROM 0.5%
Risk of talipes
Infection or sepsis
Rhesus sensitisation - given Anti-D
Uterine contractions
Can be performed after 15 weeks or once the membranes have fused
What is the chance of a fetus with ectopic beats progressing to tachycardia?
1-3%
Otherwise excellent prognosis
Management of fetus with ectopic beats
Ensure cardiac anatomy normal and rule out congenital heart disease
Weekly auscultation to r/o conversion to tachyarrhythmia
What is the prognosis for a fetus with tachyarrhythmia?
90% survival with correct medications for SVT and flutter
30% recurrent SVT
75% converted with antenatal treatment
Poor prognosis if hydrops, CHD or incorrect meds
What is the management of fetal tachyarrhythmias?
Non-hydropic - first line = Flecanide
2nd line = Sotalol and digoxin for SVT/flutter
If hydropic: Flecainide for SVT (but not flutter)
Sotalol for flutter
Amiodarone second line
What is the most important prognostic factor for fetuses with bradyarrhythmia (HR <100)
Hydrops
- almost always fatal
Also important = CHD
FHR <55 = poor prognosis
What is the management of fetal bradyarrhythmia?
Refer MFM
Check for FHx of long QT syndrome, maternal cardiac / systemic disease
Maternal anti-Ro/La antibodies
Weekly ECHO from 20 weeks
Consider treatment / delivery if FHR <55, hydrops or decreased cardiac function
Maternal steroids if 1st or 2nd degree heart block
+/- Maternal IV Ig
Salbutamol to increased HR
Deliver if >37 weeks
What percentage of fetuses with cleft lip have a syndrome?
What percentage have an associated cleft palate?
30% syndromic
80% have associated cleft palate
Management of cleft lip / palate
Detailed anatomy for associated anomalies
Amniocentesis
- unilateral = 20% aneuploidy risk
- bilateral = 30% risk
- midline = 50%
MDT care
Surgery postnatally
- lip at 2-3 months
- palate at 9-18m
Long term complications = Speech and language difficulties, recurrent otitis media, orthodontic problems
What are the possible causes of echogenic bowel?
Fetal aneuploidy (3-25%) -> T21 5.5x risk
Cystic fibrosis
Intra-amniotic bleeding (swallowing of blood)
Congenital malformation of the bowel (e.g atresia, obstruction)
FGR (mesenteric ischaemia)
Congenital infection (CMV and toxo most common)
FAS
Alpha thalassemia homozygous
Management of fetus with echogenic bowel in 1st or 2nd trimester?
Consider NIPT
Don’t recommend amnio if echogenic bowel is the only abnormality, esp if normal screening
If concerns - amnio for karyotyping + viral PCR (CMV/toxo)
Maternal serology
Parental CF carrier status screening
Serial growth scans
Isolated = no long term problems
What are the investigations for fetal hydrops?
Maternal blood group and antibody screen
Maternal FBC + blood film (screen for thalassemia)
Kleihauer
Serology - toxo, CMV, parvo, HSV and coxsackie
Imaging: Detailed tertiary anatomy USS +/- fetal ECHO
- MCA PSV for anaemia
Consider amniocentesis
- karyotype + further genetic studies
- PCR for parvo, CMV, coxsackie
Fetal blood sampling +/- IUT if anaemia suspected
Describe how you would perform ligation of the internal iliac artery
- Divide pelvic peritoneum parallel to the IFP ligament to enter the retroperitoneal space
- Identify the external iliac artery + vein laterally, and the ureter medially
- Retract the ureter medially to expose the common iliac artery
- Identify the internal iliac artery as it branches from the common IA
- Expose the internal iliac artery, identify the internal iliac vein as it runs below the artery
- Ligate the internal iliac artery distal to the posterior branch / division
- before ligating, re-identify the external iliac vessels and ureter to ensure correct vessel ligated
What percentage of brachial plexus injuries will resolve?
90%
Can take 6-12 months
What is the definition of moderate mitral stenosis? And what are the risks of significant cardiac event or mortality in pregnancy with this?
Moderate MS = Mitral valve <2cm squared, or LVEF <40%
(severe MS = area <1.5cm squared)
Risk in pregnancy = 19-27% risk of event/morbidity
Management of woman with RHD (e.g mitral stenosis) in pregnancy
MDT care
- anaesthetics referral
- dental review
ECHO each trimester unless very mild disease
Delivery in tertiary hospital
Cardiac monitoring
Early epidural
Limit 2nd stage
Strict fluid balance - avoid excessive IVF due to risk of pulmonary oedema
Admit HDU postpartum
VTE prophylaxis
What are the pregnancy risks for a woman with Turners syndrome?
Miscarriage
IUGR
Increased risk of GDM and PET
Dissection of aorta (aortic root dilatation +/- hypertension)
Increased risk of needing CS for CPD
What are the different presentations of neonatal HSV?
Skin eye and mouth (SEM) - 45%
- typically in 1st 2 weeks of life
- up to 5% deveop NDD
CNS disease - 30%
- typically 16-19 days post-natal
- seizures, lethargy, poor feeding etc
- 6% mortality, 70% of survivors have long term neurodeficits
Disseminated disease - 25%
- viraemia with multiorgan involvement (hepatitis, pneumonia etc)
- sepsis day 10-12
- 70-80% mortality
