Aneuploidy/Anomaly/Carrier testing Flashcards
High risk aneuploidy mx/counselling
scenario 1 (x2) - high risk T21 on CFTS for twins (based on high NT on 1 DCDA twin)
scenario 2 - discuss amnio to test if high risk result on screening test for AMA pt
scenario 3 - pt requesting invasive testing after reading about echogenic cardiac focus & T21
scenario 4 - 27yo, primigravida, high risk 1:50 risk on cFTS
- MDI - FMU/Genetics/Paed
- 1:300 cut off, extra chrom21
- Risk F - CHD/IUGR/SB
- Risk N - ID/Cardiac/GIT/lifespan
- screen is not diagnostic
- amnio (from 15) vs CVS (from 11)
- confirm or exclude
- guide preg mx options & decision TOP
- day, LA, USS guided
- preg loss 0.5-1%/PPROM/infection
- 1% inconclusive finding further f/u
- return if pain/bleeding/fever
- results up to 2 weeks
- follow up to plan further
- alternate - NIPT (2ndary diagnos test)
Expectant
- ~30% FDIU in affected fetus
- Fetal echo & G/S - CHD & IUGR risks
- Link up with support grp
- IOL by 39/40 to avoid SB
- Postpartum neocare + support group
TOP - selective or complete
- KCL + STOP (gestation/facility)
- KCL + mife/miso
Note - in twin preg - FDIU of affected T21 can impact the other, can choose selective feticide, <5% of inadvertent loss of non-affected twin, increase risk of PTB for non-affected twin too
Fetal anomaly - counselling
Isolated soft markers that may need further ix even if LR NIPT
- Echogenic bowel
- Single umbilical artery
- Thickened NT
- Ventriculomegaly
- Hypoplastic nasal bone
- Pyelectasis
- Short long bone
- LR NIPT = reassuring for aneuploidy
- Structural abn may have other associations
- Congenital infection, genetic syndromes, CF, IUGR, skeletal dysplasia
Echogenic bowel
- Intra-amniotic hemorrhage (swallow), T21/13/18, Turner, CMV, CF, IUGR, FDIU
Single umbilical artery
- IUGR
Thickened NT (>=6mm)
- T21, Turner, genetic syndrome & CHD
- assoc IUGR/CHD
- +/- diagnostic testing
- +/- serial GS & fetal echo
Ventriculomegaly
- assoc with congenital syndromes
Hypoplastic NB
- T21
Pyelectasis
- In isolation not an issue, but with other soft markers - risk of T21 increased
Short long bone
- skeletal dysplasia vs aneuploidy
Fetal anomaly explanation/mx (Duodenal Atresia)
Scenario - incidental finding of duodenal atresia on bkg of normal nuchal scan + FISH
- SPIKE
- bowel development issue
- Risks - assoc T21/CHD/Poly/PTB/SB/PN BO
- Tert referral
- MDI - MFM/Upper GI surgeon/Paeds
- Amniocentesis to exclude other
- USS is not conclusive - need PN XR
TOP vs Continue
If continue - - Fetal echo
- G/S- 28, 32, 36 (obstruct -> poly)
- Timing/MOD - individualized
- Postnatal surgery
Fetal anomaly explanation/mx (Encephalocoele)
Scenario - 28yo 19/40, p/w sig encephalocoele on morph incompatible with life after birth
Explanation
- bones in brain didn’t fuse
- neural tissue exposed to amniotic fluid
- affect CNS devlp - hydrocep/seizure..
- prog - size of defect & other anomlies
- recur NTD 2-4% 1 sib/10% 2 sib
- isolated, not familial
Mx plan
- Tertiary center referral
- MDI - FMF/Paeds/Neuro/SW/Genetics
- ? other anatomical anomalies
- ? amnio (CMA) ?syndrome
- ? possible fetal intervention
- ? possible postnatal intervention
- ? prognosis
Continue preg/Postnatal repair
- Serial G/S check size of head ?MOD
- Consider CTG after 34/40 - SB risk
- VD vs CS - depends on viability & size
Alternative plan
- termination of pregnancy
- mife/miso…PM
Fetal anomaly explanation/mx (Amniotic band)
Scenario 1 - 34yo, amniotic band entrapping hand/trunk on 28/40 scan
Explanation
- several theories
- bands constricting limbs/digits
- amputation of limbs/orofacial clefts
- high risk of PTB/SB
- sporadic event, recurrence rate -> baseline risk
Mx
- Tertiary Referral
- MDI - MFM/Prosthetic/Physio
- Rv of AN Hx - aneuploidy/morph
- Growth scan track progression
- Postnatal therapy - surgical correction
- Alternative = TOP
- Experimental - fetoscopic laser
Gastroschisis mx options
Scenario 1 - 18yo G2P0 19/40
- Paraumbilical abdo wall defect with prolapse of intestine
- Continue preg vs TOP (Mife/Miso)
Continue preg
- refer to tertiary center
- MDI - FMF/Paed/Surg/Psychoscoial
- rpt tertiary morph - ?assoc anomalies
- invasive testing if other anomalies
- AN paed surg review + planning
- Fortnightly G/S (risk of IUGR)
- Del btw 37-38/40
- Del at tertiary service with neonatal
- MOD - obstetric indication
note - for omphalocoele (herniation of bowel into umbilicus), would recommend diagnostic testing even in absence of other anomalies on USS - strong assoc with aneuploidies
prognosis
- gastroschisis <10% mortality
- omphalocoele 25% mortality
T21 risks
- Affects 1:400 preg
- most common auto aneuploidy
- 1:1000 @30yo
- 1:300 @35yo
- 1:100 @40yo
- need karyotype for mother & father
- carrier of balanced transloc -> higher risk of offspring with T21
- 1% recurrence if parents aren’t carriers of balanced transloc
Unexpected postnatal dx
- confirm dx - cheek swab or blood test
- exclude cx - heart - TTE
Explanation of cardiac issues on morph
- abnormal communication
- narrow arteries
- generally, not an issue in-utero
- major problem after birth
- potentially need multiple surgeries to survive
Explanation of choroid plexus cyst
- cysts - fluid collection
- cysts in brain
- in isolation, no probs
- in presence of other abno -> other brain problems
Explanation of pyelectasis & oligo
- renal damage or failure
- oligo -> resp failure postpartum -> ventilator dependence, pHTN & death
Counselling of multiple foetal anomaly
- cumulative effect of multiple anom -> major disability
- severity depends on underlying cause
- outcome depends on rx required afterbirth
- further Ix (rescan/amnio/TORCH/+/- PET screen)
- MDI - FMU/Paeds/Genetics/SW
- TOP vs Continue
Continue preg
- High risk -> Tertiary
- MDI - Obs/FMU/Paed
- Serial G/S +/- PET screen
