ANC and Screening Flashcards
Why is physiological adaptation necessary during pregnancy?
To allow mother’s body to cope with added strain
Physiological changes are often responsible for minor ailments of pregnancy
How common is morning sickness?
80-85% of pregnant woman get it
When is morning sickness worse?
When hCG levels are higher, e.g. molar pregnancy/twins
What is hyperemesis gravidarum?
Severe, persistent N&V assoc. with >5% loss of pre-pregnancy weight & ketonuria w. no other identifiable cause
What are the clinical features of hyperemesis gravidarum?
NV, dehydration, hypersalivation, orthostatic hypotension, malnourishment
How do you Rx hyperemesis gravidarum?
Steroids & hospitalisation if really bad
When does morning sickness tend to get better by?
16 weeks
What cardiac changes occurring during pregnancy?
CO increases by 30-50% - HR increases from 70 to 90bpm & palpitations common
BP drops in second trimester & returns to normal in third trimester (complain of feeling faint)
Why does BP drop in the 2nd trimester?
Expansion of the utero-placental circulation
Fall in systemic vascular resistance
A reduction in blood viscosity
Reduction in sensitivity to angiotensin (which constricts BVs)
What urinary changes occur during pregnancy?
Increased urine output (GFR increases by 50%) due to increased CO
Serum urea and creatnine decrease (due to increased GFR & dilutional effect of increased plasma vol.)
Why are UTIs more common in pregnancy? What risks do they carry in pregnancy?
Increased urinary stasis
Bladder capacity reduced to a third in third trimester due to pressure from expanding uterus, therefore more likely to have incomplete emptying & UTIs
Assoc. w preterm labour due to uterine infections so important to Rx
How do you treat hydronephrosis in pregnancy?
It is physiological in third trimester!
But does make them more prone to get pyelonephritis
What haematological changes occur during pregnancy?
Plasma vol increases by 50% & RBC by 25% –> drop in Hb by dilution from 133 to 121g/L
WCC increase slightly
Platelets fall by dilution
When should you give iron tablets in pregnancy?
Only if Hb at booking <110 or less than 100 on routine testing at 28wks
As v. unpleasant to take
NB symptoms of pregnancy v. similar to those of anaemia (SoB, tiredness etc.)
What are the respiratory changes during pregnancy?
Progesterone acts centrally to reduce CO2 –> increased TV, RR & plasma pH
O2 consumption increases by 20% but plasma PO2 is unchanged
Hyperaemia of respiratory mucous membranes (inc. BF)
What are the GI changes during pregnancy?
Oesophageal peristalsis reduced (relaxed mooth muscle)
Gastric emptying slows
Cardiac sphincter relaxes
GI motility reduced due to increased progesterone & decreased motilin
What does motilin do?
Increases intestinal contractions
Who gets pre-pregnancy counselling & where is it done?
Ideally should be everyone but 1/3rd of pregnancies are unplanned
Done in primary care
What does pre-pregnancy counselling involve?
General health measures (optimise BMI, improve diet, reduce alcohol consumption)
Smoking cessation advice
Folic acid 400mg (if high risk of NDTs take 3m before conception)
Confirm immunity to rubella
Risk assessment
Change any unsuitable drugs
Advise re complications assoc. w maternal medical problems
What does obesity increase the risk of during pregnancy?
Miscarriage, still birth, defective uterus function, VTE
Also reduces ability to measure fundal height & body’s progress
What does alcohol consumption during pregnancy lead to?
Foetal alcohol syndrome (dysmorphic features & learning difficulties)
What is involved in risk assessment during pre-pregnancy counselling?
Age
Parity
Occupation
Substance misuse
What are the outcomes with old and young age of pregnancy?
Teenagers more likely to drink and smoke and not receive ANC
>40s more likely to have pre-existing illness & higher risk of chromosomal abnormalities
Nulliparity/multiparity is more likely to get preclampsia
Nulliparity
Nulliparity/multiparity (+4) more likely to get PPH
Multiparity 4+
Why should occupation be assessed in risk assessment in pre-pregnancy counselling?
Exposure to teratogens
Not enough rest
What substances can cause neonatal withdrawal syndromes when used in pregnancy?
Heroine, methadone, diazepines
What drugs increase likelihood of placental abruption in pregnancy?
Cocaine & crack
Would you ever advise against pregnancy?
V. occasionally, e.g. aortic stenosis
What is PKU?
Inborn error of protein metabolism (inability to metabolise phenylalanine–> really high levels of phenylalanine) –> impaired mental development
What advice should you give a mother with PKU?
Ensure strict low phenylalanine diet to ensure it high levels don’t get to the developing foetal brain
What advise should you give to a pregnant lady with hypothyroidism?
Demand for thyroxine goes up during pregnancy so may req. increased dose
Normal thyroxine levels req. for foetal brain development
What advise should you give to a pregnant lady with diabetes?
Ensure good diabetic control prior to conception High blood sugar assoc with congenital abnormalities, still birth, macrosomia, pre-eclampsia
What advise should you give to a pregnant lady with epilepsy?
Major issue is anti-epileptics
Na valproate assoc. w. higher risk of spina bifida and should be avoided in pregnancy
If a woman has had a C-section before is it customary to have a planned elective C-section?
No - only after 2 C-sections it is elective
If a woman has had a DVT in her previous pregnancy what should you do?
Put her on LMWH as thromboprophylaxis
If a woman has had pre-eclampsia in her previous pregnancy what should you do?
Start her on low dose aspirin
Putting on high dose folic acid/low dose aspirin may be done if there was __________________ in the previous pregnancy.
Pre-term delivery, IUGR, foetal abnormalities
If baby remains breech after ____weeks offer _____.
36wks offer ECV (turning of baby inside tummy)
If this fails - elective C-section
Is antenatal screening compulsory?
No but it is offered
What is the aim of antenatal screening?
Allows conditions to be detected early in symptomless population to be treated for mother/baby
What are all pregnant woman screened for?
Rubella, Hep B, syphilis, HIV
Consent req. for all screening!
How do we test for rubella?
Test for rubella antibodies
What is congenital rubella syndrome?
Occurs if woman is infected with rubella up to 16 weeks of pregnancy
–> mental handicap, deafness, heart defects
If a mother is infected with Hep B what can we do?
Provide passive & active immunisation for the baby
If a mother is infected with syphilis what can be do?
Rx with penicllin
Untreated syphilis can have what effects on the unborn child?
IUGR, hepato-splenomegaly, anaemia, thrombocytopenia, skin rashes
If a mother has HIV how can we try to prevent the child from getting it?
ART to reduce viral load
C-section delivery
Avoid breast feeding
Do we screen for anaemia?
Iron deficiency anaemia screened for with FBC at booking & 28 weeks
How do we treat iron deficient anaemia?
Iron tablets
Additional Fe req. to make extra maternal RBCs as normal adaptation of pregnancy and needed b y foetus and placenta
What is isoimmunisation?
Development of Ab against blood groups
What is rhesus dx?
Rhesus -ve mother carrying rhesus +ve baby will develop anti-D if foetal RBCs enter maternal circulation
Occurs with miscarriage beyond 12 weeks, ectopic pregnancy, APH & at delivery)
Ab develop at first pregnancy
In subsequent pregnancies with rh +ve babies, anti-D crosses the placenta and leads to destruction of foetal RBCs –> foetal anaemia & death
Why do we screen for rhesus factor?
To identify at risk woman and give them anti-D - which destroys foetal RBCs in maternal circulation before maternal immune system can make Ab against them
What an we do if we identify a woman with existing anti-D Abs?
Monitor the pregnancy more closely to detect foetal anaemia & provide Rx
When is anti-D given to Rh-ve woman?
Prophylactically & after sensitising events
What USS scans do we do in ANS?
First visit scan
Detailed anomaly scan
What is the first visit scan for?
Ensure viable pregnancy, rule out multiple pregnancy
Identify abnormalities incompatible with life
Offer & carry out Down’s screening
What is the detailed anomaly scan for?
Systemic structural review of baby
Can identify problems that need intrauterine/post-natal Rx
What is the overall risk of Down’s syndrome?
1 in 700
What is the cut off for high risk of Down’s syndrome?
1 in 150
Offer definitive testing in this group
How are maternal age and Down’s syndrome linked?
1 in 30 risk of Down syndrome at 45y
Apart from increased age, what increases the risk of Down’s syndrome?
Personal/FH of chromosomal abnormalities
What must you make the mother/partner aware of when screening for Down’s?
Will only provide risk of their baby being affected
May lead to difficult decisions regarding termination of pregnancy
When is first trimester screening carried out?
10-14 weeks
What does first trimester screening involve?
Maternal risk factors, serum b-hCG, pregnancy associated plasma protein A (PAPP-A) & foetal nuchal translucency measurement (bigger = higher risk of Down’s)
If high risk (>1 in 150) then offer further screening (CVS, amniocentesis, NIPT)
What is CVS?
Chorionic villus sampling
Sample of chorionic tissue taken and tested
Done between 10-14 weeks
1-2% risk of miscarriage
What is amniocentesis?
Sample of amniotic fluid taken and tested
15 weeks onward
1% risk of miscarriage
What is NIPT?
Non-invasive prenatal testing
Maternal blood taken and can detect fetal cell free DNA & check for chromosomal trisomies
Not offered on NHS
If high risk still recommend to have invasive testing to confirm
Who is offered NDT screening?
Not routinely offered anymore
If personal/HF of NTD - what are you recommended to do during pregnancy?
5mg folic acid to reduce risk of NDT
In relation to NDTs what will: the first trimester US detect?
Anencephaly & sometimes spina bifida
When would you carry out second trimester biochemical screening?
If unable to get NT measurement
Maternal serum tested for alpha fetoprotein (>2MoM high risk & warrants Ix)
Second trimester screening at ______ USS will detect _____ of neural tube defects
20 weeks
>90%
What are the USS markers for NTD?
Cystic areas in base of spine
Lemon shaped skull that points down at the front
Banana shaped cerebellum
What is involved in the second trimester USS?
Performed with purpose of detecting foetal abnormalities
Poor at picking up chromosomal abnormalities but good at picking up major structural abnormalities
Cleft lip/cleft palate cannot be picked up on USS.
Cleft palate cannot
What may lead to difficulties in seeing the foetus properly during the second trimester USS?
Foetal position & maternal BMI
