MFM Flashcards
CF
Carrier 1:35
Affected 1:5000
Spinal muscular atrophy
1:50 carrier
1:10,000 affected
Severe muscular weakness, death, usually in childhood
Fragile X
1:300 carrier
1:7000 males affected
Severe intellectual disability and autism
Trisomy 21
1:660 births
Features vary secondary to mosaicism
Features in neonates
- Hypotonia
Facial characteristics - short, webbed neck, low nasal bridge, epicanthal folds, upward slanting of eyes
- Cardiac or GI manifestations
- Brachycephaly
infancy: developmental delay
Intellectual disability, GI malformations, Auditory and / or visual defects, hypothyroidism, epilepsy,
55 is average age
Recurrence - maternal age <35 = 1/100
>35 = twice population risk
If familial Robertsonian translocations: recurrence 1% for male, and 12% for female
Trisomy 13 - Patau syndrome
1:5000 births
4/7 of life average length - cardiac defects, poor brain stem control.
Sometimes can get partial or mosaic trisomy 13 which means less severe
Craniofacial malformations, ocular malformations, neurological malformations, limb abnormalities, cardiovascular abnormalities, omphalacele, diaphragm abnormalities, etc…..
severe intellectual disability
Recurrence low
Trisomy 18 - Edwards syndrome
1:3000 births
Not usually compatible with prolonged survival
Features can be less severe in case of mosacism
Severe developmental delay
Multiple malformations including cardiac, urinary tract, renal, joint contractures, low birth weight, hearing loss, rocker bottom feet,
Severe developmental delay and disability
Of those babies that are liveborn, 30% die in the first month of life and 90% die by 12 months
Recurrence low!
Klinefelter syndrome 47XXY
1:500 - 1000 births
Primary hypogonadism
Pubertal gynaecomastia and small testes
Tall stature
Infertile
Delayed language
Refer to paeds endocrinologist for treatment with testosterone (function of testes not restored) Occ men can be fertile by ICSI
Recurrence risk low
Turner syndrome XO
1:2000 births
Poor growth, pubertal delay
short stature
lack of sexual development at puberty and streak ovaries, primary amenorrhoea, infertility, normal intelligence
Webbed neck, heart defects, renal abnormlaities,
Majority will be mosaic in some tissues
FSH raised
Refer paeds endocrinologist
Give E and GH
HTN - treat
Frequent otitis media
Refer for IVF
Increased risk IBD, hypothyroid, diabetes
Sleeping issues
Deefing difficulties (high arched palate or cleft)
Recurrence risk low!
Toxoplasmosis main points
Acute infection in mother usually asymptomatic
If immunocompetent don’t transmit to fetus
Risks:
1st trimester 10% transmission, 90% fetal damage
2nd trimester: 40% transmission, 20% fetal damage
3rd trimester 90% transmission, 10% damage
Risk to fetus: fetal liver and brain calcifications, ventriculomegaly, non immune hydrops, death, IUGR
Triad: chorioretinitis, hydrocephalus, intracranial calcifications - if no treatment high risk of abnormality CNS and vision impairment
Do IgM and IgG serology with IgG avidity, and repeat 2/52
M -MFM referral
U - tertiary USS
T - already done TORCH
A - amniocentesis PCR >4/52 from infection (do not do <18/40), can have false negatives
N - NICU consult
T - TOP consider
I - Written INFO
S - Social work
M - management particular to condition
- Spiramycin 1g TDS until delivery (significantly reduces the proportion of infected fetuses that develop severe neurological sequelae)
If fetal infection confirmed or even if fetal infection not confirmed on PCR: add pyrimethamine and sulfadiazine and folinic acid
If fetal infection confirmed consider TOP
If fetal infection not confirmed still do monthly USS to assess for brain changes
Management of infant: ophathlmologist, auditory, neurology review, head USS / MRI, lab serology - IgM and IgG, PCR bloods / CSF / placenta. Treatment for one year
Listeria main points
40-50% risk IUFD in second / third trimester
Amoxicillin IV ≥2g q4-6h for 2/52
Urgent delivery depending on severity of maternal illness / gestation
Full septic screen on neonate - can die, granulomas, meconium, pneumoniits, conjunctivitis –> given amoxicllin regardless and if CSF positive - longer term.
Can be early or late onset.
Hydrops mnemonic
CAUSTIC
C - chromosomal (turners, trisomy 13, 18, 21, noonans)
A - anaemia - parvo, rhesus disease, FMH, alpha thalassaemia, G6PD, TAPS
U - unexplained e.g. metabolic?
S - Structural - Chest: CCAM, CDH, chylothorax, skeletal dysplaisa, GI and GU abnormalities, placental / fetal tumours
T - Twins - TTTS / TAPS, TRAP
I - Infection - parvovirus, coxasackie, STORCH, Varicella
C - Cardiac - tachyarrhytmia, bradyarrhythmia, high output state, cardiac structural anomaly
- Pertinent questions
o Any recent viral infections? (fever, rash, lymphadenopathy)
o Recent trauma / fall – large FMH
o Ethnicity, consanguinity, and family history (alpha thalassaemia, G6PD)
o Any suggestion of SLE or Sjogrens (anti Ro/La and heart block)
o Profession – childcare worker, teacher, risk of infections
Examination – Key points
- General inspection
- Vitals: temperature, BP, oxygen saturations (mirror syndrome)
- Cardiorespiratory: pulmonary and peripheral oedema, hyperreflexia, clonus (mirror syndrome)
- Obstetric exam
o Fundal height
o Subjective assessment of amniotic fluid
o Presentation and lie
o Any fetal movements felt
o Fetal heart / CTG if suitable gestation
Ix
- G+H and titre if Ab positive
- Kleihauer
- PET screen (mirror)
- FBC / DNA studies / partner testing
- G6PD screen if ethnicity suggestive (jews, nigerians, thai etc)
- TORCH screen (toxo, syphilis, varicella, zika, rubella, CMV, HSV)
- Anti Ro / La if bradyarrhythmia
- TFTs and TSHRAb if tachycarrhtymia
- CTG if suitable
Ultrasound
- Tertiary view for structural anomalies
- Fetal ECHO
- MCA PSV for fetal anaemia and sometimes fetal blood sample
- Growth and wellbeing (UAPI, MCA, CPR, DV)
- Compartments affected
Amniocentesis
- PCR for infections
- Chromosomal microarray
Prognosis
- If born with hydrops 50% risk mortality - dependent on cause
Chromosomal abnormality poor prognosis.
Fetal echogenic bowel
If isolated = good prognosis, 1% in second trimester
Fetal aneuploidy (T21»_space; T13, T18)
meconium
Intra-amniotic bleeding - swallowing of blood
Congenital malofromations of bowel
IUGR
Congenital infection
FAS, alpha thalassaemia homozygous
CF
Offer
NIPT
TORCH screen
Genetic carrier screening
Tertiary anatomy scan
Amnio
MFM
Monthly growth scans
(MUTANTISM)
Choroid plexus cyst
in Isolation not a big deal
Offer NIPT
Not for invasive testing if no other abnormalities
Can be ass with T21 and T18 (1%)
Neural tube defect
Neural tube closes day 21 - 28
Open defects - myelomeingocele (open spinal cord, no skin), meningocele (protrusion of membranes), encephalocele (protrusion brain from part of skull) , anencephaly (missing part of skull)
Closed NTDs: spina bifida
Prevalence
5-20 / 10,000 births
5mg folic acid if
- Prev child with NTD, mother with NTD, close family member with NTD.
- Insulin treatment for diabetes
- Antiepileptic treatment - carbamazepine, sodium valproate
Screen everyone, majority found in first trimester
Prolonged exposure of neural tissue to amniotic fluid can cause injury to the cord - MSK weakness, bowel and genitourinary dysfunction
M - MFM referral
U - USS: Screen for other abnormalities - oral clefts, malformations in MSK, renal, cardiovascular systems
T - not needed
A - offer microarray 6% risk chromosomal abnormality
N - NICU
T - TOP if severe
I - written info
S - SW
M - management as per condition - can sometimes consider fetal surgery
Myelomeningocele signs / important facts
Lemon sign - frontal bone scalloping
Banana sign: abnormal cerebellum
Ass with Arnold Chiari II malformation with caudal displacement of brain
Ass with T 18, maternal diabetes, AEDs
Risk of non chromosomal abnormalities low
MUTANISM
4 weekly growth
Aim NVB
Prognosis: 35% 5 year mortality rate, 20% die in first 12/12, 25% stillborn
Surviving infants usually have paralysis in the lwoer limbs, double incontinence, hydrocephalus. Normal intelligence
