Antenatal care Flashcards
What is antenatal care?
regular and systematic care during pregnancy to improve maternal and foetal outcome
care should be individualised
What are the main objectives of (good) antenatal care?
PROMOTE + MAINTAIN
physical, mental and social health of mother and baby
(education: nutrition, personal hygiene, labour)
DETECT + MANAGE
complications from pregnancy and labour
DEVELOP
birth preparedness and ‘complication readiness’
HELP PREPARE
mother to breastfeed, for puerperium, and taking care of child going forward
What may constitute ‘promotion of health and disease prevention’ in antenatal care?
- tetanus toxoid
- nutritional supplementation
- tobacco
- EtOH use etc
What existing diseases should be screened for and managed in antenatal care?
- HIV
- syphilis
- TB
- lifestyle disease (HTN, DM etc)
What are the drawbacks of antenatal care?
- medicalisation of a normal pregnancy
- maternal anxiety
- unnecessary interventions
- unclear whether there is benefit of such an approach
- cost: resources and social costs
- risk approach in predicting complications: efficiency? effectiveness?
What are the types of care that antenatal care could comprise?
- midwifery/GP/HCP
- Shared Care
- Consultant-led/Hospital based (usually due to pre-existing conditions or high risk pregnancy)
How may visits are typically advised for antenatal care?
LOW RISK WOMEN
usually 14 visits which may be reduced to 7-10 visits w/o affecting safety outcomes
and timing of visits should be tailored to that woman
Women should be welcomed to attend further visits, if they, midwife and doctor perceive a need or if complications arise
What is the purpose of an ‘early ultrasound’ in antenatal care?
- dating
- ensures consistency of gestational age assessments
- improves the effectiveness of mid-trimester Downs serum screening
- reduced need for labour induction post-41 wks
When is a dating scan most accurate?
the earlier it is performed - this is when all foetuses are roughly similar sizes for their gestational age before greater variation is present
Why is screening gestation-dependent? What does this mean?
key markers used to distinguish structural abnormalities may be missed if gestation is inaccurate
dating scan where crow-to-rump length or biparietal measures are taken should be performed first
What measures are taken during the dating scan? When should this be performed?
ideally 10-13 weeks
crown-to-rump length: used to determine gestational age
beyond this age, gestational age can be estimated using abdominal circumference or biparietal diameter
What maternal measures should be taken at the first booking appointment?
- maternal weight
- height
=> used to calculate BMI
What is the relationship between BMI and maternal/foetal risk?
linear risk: increasing BMI associated with increased risk to mum and baby
Why is pelvic examination not routinely utilised in antenatal care?
does not accurately assess
- gestational age
- preterm labour risk
- cephalo-pelvic disproportion
What screening is in place for anaemia in pregnant women?
- screening to take place in early pregnancy (at first appt and at 28 wks)
- allows adequate time for Rx if needed
- iron supplementation may be instigated if necessary
12 WEEKS
anaemia detected is likely to have been present pre-pregnancy e.g. sickle/thal. trait etc
28 WEEKS
maximal haemodilution occurs here, can therefore monitor if pregnancy-induced anaemia
Why is anaemia detected at 28 weeks gestation not ideal for maternal health heading into labour?
no reserve for haemorrhage (PPH)
What screening is performed for blood grouping and Rh typing in antenatal care?
- women should be offered testing
- if woman is Rh-negative, biological partner should be offered testing
- If partner is also Rh-negative, then anti-D prophylaxis may need to be started
- recommended that routine antenatal ANTI-D PROPHYLAXIS is offered to all non-sensitised Rh-negative pregnant women
What is a Rhesus baby?
Mother is Rh-negative and baby is Rh-positive
Mother: raises maternal Ab against foetus which can cause issues such as neonatal jaundice
- relatively rare
- Rhesus Ag is recessive
What is the screening protocol for foetal abnormalities in antenatal care?
- offered anomalie scan at 18-21 weeks to check for structural abnormalities
- offered screening for Down’s (Nuchal translucency and serum)
- DS test: detection rate >60% and false +ve rate <5%
What is the combined test for foetal abnormalities?
occurs at 12 weeks
- nuchal translucency (USS)
- serum biochemical screen (bHCG and aFP)
What is Nuchal translucency?
looks at the amount of fluid behind foetal neck
increased fluid here is correlated with chromosomal abnormalities eg. T13, T18, T21
aetiology: impaired cardiac development, lymphatic drainage or ECM formation
What tests may be offered if there is an abnormal combined test?
if adjusted risk from combined test is > 1:150 then amniocentesis or chorion villus sampling may be offered
However, risk of MISCARRIAGE, so depends on parents wishes
Cells taken from these methods can then be genotyped/karyotyped for definitive Dx
What screening for infections occurs in antenatal care?
- asymptomatic bacteria by MSU early in pregnancy (and Rx). Correlation with this (untreated) with preterm birth risk
[NO ROUTINE SCREENING for bacterial vaginosis: no evidence that this reduces risk of preterm birth]
What is bacteriuria?
presence of leukocytes and proteins in urine
Why is there increased risk of preterm labour with bacterial infections in the mother?
infective process -> inflammatory response -> initiation of labour
What other infections in the pregnant mother should be screeened for?
- rubella
- syphilis (congenital syphilis can be prolonged and silent)
- HIV
- HepB (HBV)
What infections is screening not effective in (antenatally in mother)?
- HCV
- Chlamydia
- Group B strep
- CMV
- Toxoplasmosis (cat litter)
What screening occurs antenatally for generally medical conditions?
GESTATIONAL DM
no routine screening for this, but urine dipstick will be performed at every appt. If dipstick positive for glucose and in high risk individuals, OGTT will be performed
PRE-ECLAMPSIA
regular BP measures and urine dips to be taken at every appt
presence of proteinuria and elevated BP indicates pre-eclampsia
How is the foetal health monitored during pregnancy?
FOETAL SIZE
monitored at each appt, to check foetus is appropriately sized for gestational age
FOETAL MOVEMENT
should be assessed by mother, decrease in movement for >1 day can indicate foetal distress
UTERINE SIZE
normal growth is 1cm per 1 wk gestation
What measures of foetal health are NOT ROUTINELY used during pregnancy?
- foetal HR (auscultation)
- antenatal electronic foetal HR (CTG): only used in high risk pregnancy or during labour for those with epidurals
How should medications be used during pregnancy?
- prescription meds should be used as little as possible
- folic acid should be started 3 months preceding conception
- vitamin D supplementation should routinely be offered
Why is folic acid used before and during pregnancy?
dose = 400 mcg per day
reduces risk of neural tube defects e.g. spina bifida, anencaphaly
What medications should NOT be offered during pregnancy?
- iron supplementation (unless indicated for anaemia)
- Vitamin A (teratogenic at > 700mcg and half life is ~ 6mnths)
What investigations are performed at the booking visit for antenatal care?
RISK ASSESSMENT
history and examination
SCREENING TESTS
- FBC
- Grouping and Rh
- infection screen (blood)
- Urine dipstick/MSU
Establish Mx and care plan
What is Naegle’s rule with dating pregnancy?
Last menustrual period (LMP)
Add 7 days and 9 months
Periods have to be 28 day cycles. If not, adjustment need to be made to incorporate irregular cycles etc
