Congenital Abnormalities and Their Identification Flashcards
Which trisomy is Down’s syndrome?
Trisomy 21
Which trisomy is Edward’s syndrome and what is the prognosis?
- Trisomy 18
2. Most die soon after birth
What is this a presentation of?
Newly born child, small chin, low-set ears, rocker-bottom feet, VSD.
Edward’s syndrome
Which trisomy is Patau’s syndrome and what is the prognosis?
- Trisomy 13
2. Most die soon after birth
What is this a presentation of?
Newly born child, microcephaly, holoprosencephaly, exophthalmos, cleft-lip and palate.
Patau’s syndrome
When does chorionic villus sampling take place?
11-13 weeks
What is this describing?
Placenta is sampled transabdominally under continuous USS.
Chorionic villus sampling
What is the process after the initial harvesting in chorionic villus sampling?
- Karyotyping using FISH and PCR takes 2 days
2. Enzyme and gene probe analysis takes 3 weeks using array-CGH
What are the risks involved in chorionic villus sampling?
- Miscarriage risk of 1-2%
- Increased risk of transmission of blood-borne viruses
- Anti-D needed in Rh-ve
When is amniocentesis carried out?
From 16 weeks
What is this describing?
Aspiration of amniotic fluid containing foetal cells shed from skin, small needle passed transabdominally under continuous USS.
Amniocentesis
What is amniocentesis used for and what is the process after initial harvesting?
- Can diagnose foetal infections like CMV
2. Karyotyping using FISH and PCR takes 2 days
What are the risks involved in amniocentesis?
- Miscarriage risk of 1%
2. Anti-D needed in Rh-ve
What is the non-invasive screening method for trisomy (retard cunt) disorders?
Cell free foetal DNA
What CNS abnormalities does the anomaly scan identify?
- Spina bifida
2. Anencephaly (incompatible with life)
What abdominal abnormalities does the anomaly scan identify?
- Exomphalos - partial extrusion of abdominal contents in peritoneal sac, offer amniocentesis
- Gastroschisis - free loops of bowel in amniotic cavity
What are the risk factors for foetal cardiac abnormalities on an anomaly scan?
Congenital cardiac disease, diabetes mellitus, AEDs, previous deliveries, chromosomal abnormalities.
What chest abnormalities does the anomaly scan identify?
- Diaphragmatic hernia - causes pulmonary hypoplasia
2. Pleural effusion - may cause pulmonary hypoplasia and hydrops
What gastrointestinal abnormalities does the anomaly scan identify?
- Oesophageal atresia and trachea-oesophageal fistula - stomach is small, polyhydramnios present
- Duodenal atresia - double-bubble USS sign, Down’s syndrome common, polyhydramnios
- Lower gut atresia - dilated bowel, meconium ileus due to CF common
Which urogenital abnormality does the anomaly scan identify?
Hydronephrosis - due to obstruction/reflux, children prone to infection and renal damage
What skeletal and facial abnormalities does the anomaly scan identify?
- Skeletal dysplasia syndromes
2. Cleft lip and cleft palate
What is this describing?
Extra fluid accumulates in 2 or more areas in the foetus.
Foetal hydrops
What are the two different causes of foetal hydrops?
- Immune - due to anaemia and haemolysis (Abs)
2. Non-immune - chromosomal/structural abnormalities, CMV, PV-B19, twin-twin transfusion syndrome.
What is the cure for foetal hydrops?
- Transfusion for anaemia
2. Laser ablation for twin-twin transfusion syndrome
What is this describing?
Excess amniotic fluid in the amniotic sac.
Polyhydramnios
What are the causes of polyhydramnios?
- Idiopathic
- Established diabetes mellitus and gestational diabetes
- Twins (twin-twin transfusion syndrome)
- Foetal anomaly
What is this a presentation of? Maternal discomfort (urinary incontinence, breathlessness), large for dates, foetal parts difficult to palpate.
Polyhydramnios
What are the complications of polyhydramnios?
Preterm labour, abnormal lie, malpresentation, PPH.
What is the management for polyhydramnios?
- Reduce fluid - if 34/40 and severe then amnioreduction/NSAIDs, steroids also if <34.40
- Deliver - vaginal unless persistent unstable lie
