Antenatal Care 1 Flashcards
What is autosomal dominant inheritance?
Only mutated copy of the gene is needed for person to be affected by disorder
e.g. Marfans
What is autosomal recessive inheritance?
Both copies of gene must have mutations
parents each carry one copy of mutated gene
e.g. CF
What is X-linked dominant?
mutation in genes on the X chromosome
males most severely affected as only one X
no male to male transmission
What is X-linked recessive?
Both X in females must be mutated to be affected, but will affect males if mutated in the single X chromosome
What is Y-linked recessive?
mutated gene on Y chromosome
only passes from father to son
What are the common congenital abnormalities?
neural tube defects - spina bifida and anencephaly
folic acid supplementations reduces incidence
cardiac defects can be diagnosed with US and can be corrected after birth with surgery
defects in the abdominal wall - exomphalos and gastroschisis
chest defects - diaphragmatic hernias, pleural effusions
GI defects - oesophageal atresia and trachea-oesophageal fistulae, duodenal atresia
GU - hydronephrosis, posterior urethral valves
Skeletal - skeletal dysplasia, limb abnormalities
Fetal hydrops - extra fluid in 2+ areas of the fetus
What is important to consider when prescribing in women of child bearing age?
drugs have harmful effects on the fetus at any time during pregnancy so bear in mind when prescribing
Why is safe prescribing important in the 1st trimester?
drugs produce congenital malformations (teratogenesis), period of
greatest risk from 3 rd -11 th week of pregnancy
Why is safe prescribing important in the 2nd and 3rd trimester?
drugs affect growth or functional development of fetus, or toxic effects on fetal tissues
Why is safe prescribing important shortly before term and during labour?
adverse effects on labour or on neonate after
delivery
What are the main principles of safe prescribing in pregnancy?
only prescribe if benefit to mother is thought to be greater than risk to fetus
all drugs should be avoided in the first trimester
smallest effective dose
use usually safe drugs rather than new/untried drugs
What are the aims of antenatal care?
- Detect + manage pre-existing maternal disorders that may affect pregnancy
outcome - Prevent/detect + manage maternal complications of pregnancy
- Prevent/detect + manage fetal complications of pregnancy
- Detect congenital fetal problems if requested by patient
- Plan with mother the circumstances of delivery to ensure maximum safety for
mother + baby, and max maternal satisfaction - Provide education + advice regarding lifestyle + ‘minor’ conditions of pregnancy
What screening is done during booking (before 10 weeks)?
- check rubella immunity and need for postnatal immunisation
- check for hep B to allow immunoglobulin administration to neonate
- check for syphilis infection and HIV status
- arrange for genetic counselling/later CVS if at risk of inherited disorder
What screening is done between 9-12 weeks?
USS to date pregnancy and identify twins
advise regarding chromosomal trisomies
counsel and offer CVS is high risk
What screening is done between 18-21 weeks?
routine anomaly US to detect structural abnormalities
counsel and offer CVS if high risk