Antenatal Care: Aneuploidy, Teratogens Flashcards
Who is responsible for antenatal care
Midwives
When are obstetricians involved
High-risk pregnancies
When is booking appointment
12W
How many appointments will an uncomplicated nulliparous women recieve
10 appointments
When is the early US scan done
11-13+6
When is structural anomaly scan performed
18-20+6
When is first-dose anti-D prophylaxis started for rhesus negative women
28W
When is second-dose anti-D prophylaxis started for rhesus negative women
34W
When is gestational diabetes screened for
- Booking if previous GDM
- 24-28W if at-risk
What indicates screening for GDM
- First-degree relative diabetes
- Asian
- Macrosomic baby
If a women had GDM in a previous pregnancy, when should OGTT be performed
16 and 28W
What is a pregnant women eligible for
Healthy start multivitamin
What does a healthy start multivitamin contain
Vitamin C
Vitamin D
Folic acid
When is folic acid given
Pre-conception to 12W
Why is folic acid given
Prevent NTD
When is 5mg folic acid given
Anti-epileptics Child with NTD Diabetes BMI >30 HIV Co-trimoxazole
When is nuchal translucency looked for
11-13+6
What are 3 conditions where nuchal translucency may be increased
- Down syndrome
- Congenital heart defect
- Abdominal wall defect
What are 3 conditions that may cause hyperechogenic bowel
- Cystic fibrosis
- Downs syndrome
- CMV
What is seen on anomaly scan
Look at each structure independently
What is Down’s syndrome also known as
Trisomy-21
What is the most common aneuploidy
Trisomy-21
What genetic defect is in 95% of trisomy-21
Non-Dysfunction
What is non dysjunction
When two homologous chromosomes fail to separate in downs syndrome
What are two other genetic defects possible in trisomy 21
Robertsonian
Mosaicism
What % is due to balanced robertsonian translocation
5
What balanced translocation happens in D2
Long-arm chromosome 14, joins long-arm chromosome 21
What is mosaicism
two genetically different populations
What is risk Down syndrome in under 25’s
1:1500
What is risk Downs syndrome in 30
1:900
What is risk Down syndrome in 35
1:400
What is risk in Down syndrome in 40
1:100
What is risk in Down syndrome in over 45
1:30
What differences can be seen in the eyes of DS child
Large palpabrae fissures
Brushfield spots
What are brush field spots
Grey-brown discolouration of the iris
What is an oral feature of downs syndrome
Small mouth
High-arch palate
What is a nasal feature of downs syndrome
Flat broad nasal bridge
How do the ears appear in downs syndrome
Small, round, low-set ears
What can be seen on hands of downs syndrome child
Single transverse palmar crease
What can be seen in feet of someone with downs syndrome
Large sandal gap
What is a sandal gap
Large gap between big and second toe
What heart defects are seen in DS
AVSD (40%)
VSD (30%
ASD (10%)
What bowel defects are seen in DS
Duodenal atresia
Hirschsprungs
What haematological defect is seen in DS
ALL
What neurological deficits are seen in DS
Epilepsy
Early-onset alzheimer’s disease
What motor features are seen in trisomy 21
Hypotonia
Delayed motor development
What MSK features are seen in trisomy 21
Short-stature
Obesity
What cognitive features are seen in DS
Intellectual disability
What are all women in the UK offered
Screening DS with combined test
When are women screened for DS
11-13+6
What is used to screen for DS
Combined test
When can quadruple or triple test be offered to screen for DS
15-20W
What are the 4 components of the combined screening test
- Maternal Age
- Nuchal translucency
- bHCG
- PAPP-A
When is quadruple test performed
16W
What is PAPP-A
Produced by placenta
What do low levels of PAPP-A indicate
Low levels indicate poor placentation - associated with trisomy. (Also low in smokers)
What are two types of non-invasive pre-natal testing
SAFE
IONA
How does the SAFE and IONA test work
Looks for foetal blood cells in circulation
What is the problem with non-invasive pre-natal testing
Still considered screening test, women will require diagnostic testing
What is a ‘high-risk’ result
Less than 1 in 150 risk DS
What is offered to women with ‘high-risk’ result
Diagnostic testing
When can chorionic villus sampling be performed
10-13W
Explain CVS
Needle inserted trans-abdominally to take sample from placenta
How long does karyotyping for CVS take
2d
How long does enzyme analysis for CVS take
3W
What is the main advantage of CVS
due to being earlier than amniocentesis - means termination happen earlier
What is % miscarriage with CVS
2%
What is an additional problem with CVS
mosacism - cells of placenta may be different
When is amniocentesis offered
> 16W
What is amniocentesis
needle inserted trans-abdominally and cells of amniotic fluid taken
What is % miscarriage in amniocentesis
1%
How long does karyotyping take in amniocentesis
3W
How long does PCR take in amniocentesis
3d
What is life expectancy of downs syndrome
55 years
What is Edwards Syndrome also known as
Trisomy 18
What causes Edward’s syndrome
Non-Dysfunction
What is a risk factor for Edward’s syndrome
Maternal Age
What are the presenting features of Edward’s syndrome
Micrognathia
Cleft palate
Low-set round ears
Rockerbottom feet
VSD
What is the prognosis of edward’s syndrome
1-year
Define patau’s syndrome
Trisomy-13
What causes patau’s syndrome
Non-dysjunction
What is a typical feature of patau’s syndrome
Holoprosencephaly
What is holoprosencephaly
Where the forebrain of both hemispheres fails to seperate
What are other features of patau’s syndrome
Cleft palate
Polydactyl
Exomphalos
What is the prognosis of patau’s syndrome
Die shortly after birth
What is the genetics in Turner’s syndrome
45XO
What causes Tuner’s syndrome
Absence X chromosome in females
What are 4 features of turner’s syndrome
Short-stature
Webbed neck
Streak ovaries
Coarctation aorta
What is Kleinfelter syndrome
47XXY
What are 5 features of Klinefelter’s syndrome
Eunuchoid Testicular dysgenesis Reduced fertility Mitral valve prolapse Gynaecomastia Osteoporosis
What is eunuchoid presentation
Tall, slim, long extremities
How does cystic fibrosis present
Meconium ileum in new-born.
Child: FTT and steatorrhoea
How is cystic fibrosis screened for
IRT on neonatal blood spot (5d)
What is used to diagnose cystic fibrosis
Sweat chloride test
When are structural anomalies identified on scan
18-21+6
What are two most common neural tube defects
Anencephaly
Spina bifida
What is anencephaly
Absence cranial vault and cerebral cortex
What is prognosis of anencephaly
1-year
What is spina bifida
Failure of vertebrae to fuse - causing herniation spinal cord
What are the 3 types of spina bifida
- Occulta
- Meningocele
- Myelomeningocele
What is spina bifida occulta
When vertebrae fail to fuse - but there is no herniation of the spinal cord
What is meningocele
Vertebrae fail to fuse - causes herniation meninges
What is myelomeningocele
Vertebrae fail to fuse - herniation meninges and spinal cord
How does myelomeningocele present
Abnormal neurology below the lesion
How are NTD prevented
400mcg Folate from 3m pre-conception to 12W
What is the most common anomaly detected on structural anomaly scan in children
Cardiac anomalies
What is the most common structural cardiac defect
VSD
What murmur will be present in VSD
Pansystolic
What is the mnemonic to remember teratogenic drugs
TERATOWA
Thalidomide Epileptic medications Retinoids ACEi, ahminoglycosides Third element = lithium Oral contraceptives Warfarin Alcohol
What are complications of ACEi during pregnancy
Renal dysgenesis
Prolonged foetal hypotension
What are complications of alcohol during pregnancy
Absent philtrum
Hypoplastic upper lip
Microcephaly
If a foetus has an absent phitrum and hypo plastic upper lip what is the cause
Foetal alcohol syndrome
What does cocaine use in pregnancy cause
IUGR
Placental abruption
Pre-maturity
What abnormality does lithium use in pregnancy cause
Ebstein’s anomaly
What is Ebstein’s anomaly
Low insertion of the tricuspid valve causing large right atrium and small right ventricle
What causes Ebstein’s anomaly
Lithium
What does thalidomide use in pregnancy cause
Limb-reduction defects
What does valproate use in pregnancy cause
NTD
What is a mnemonic to remember antibiotics toxic in pregnancy
MCAT
What antibiotics are toxic in pregnancy
Metronidazole
Chloramphenicol
Aminoglycosides
Tetracyclines
What does metronidazole cause if used in pregnancy
Hepatic impairment
What does chloramphenicol cause if used in pregnancy
Grey-baby syndrome
What do amino glycoside cause if used in pregnancy
Ototoxic
What do tetracyclines cause if used in pregnancy
Yellow discolouration teeth and weakness bones