Care in Pregnancy Flashcards
How do we assess the robustness of a screening test?
Sensitivity and specificity
Sensitivity= true positive/ all positives Specificity= true negative/ all negatives
Describe appointment schedule in low risk and high risk pregnancy and who carries that out?
Low risk pregnancy series of routine antenatal with midwife
Booking appointment 8-12 weeks
before 14 weeks is trisomy screening
Review 16 weeks
Anomaly scan at 20 weeks
Seen again 25, 28, 31, 34, 36 weeks
Term is any time 37 – 42 weeks
If haven’t delivered by 38 weeks she is seen again by midwife, then at 40,41 and at 42 weeks if not delivered
High risk pregnancies have care lead by consultant obstetrician. High risk pregnancy has appointment schedule determined by what is going on in the pregnancy (should as minimum get same amount of appointments as normal pregnancy).
Describe the 8-12 week booking appointment?
this is carried out by the midwife check height, weight, BP Blood tests to look at Hb, ABO, rhesus status and antibodies, syphylis, HIV, Hep B Urinanalysis Secondary appointment for US
Describe the 8-12 week US?
Confirm viability of pregnancy. This is also the most accurate time to measure gestation using Crown Rump Length and estimate EDD. If miss 8-12 weeks age is estimated using head circumference which is less accurate than CRL. Can also detect any major anomalies.
What is used to calculate due date before the dating scan at 8-12 weeks?
Naegeles rule predicts EDD based on onset of women’s LMP. Add on 9 months 7 days to get due date > 280 days. Scan is much more accurate so results of that should be used.
What do you need to see on scan to tell if a pregnancy is viable?
fetal heartbeat (not visible until 6-7 weeks)
When are scans offered in pregnancy?
8-12 week booking scan
20 week anomaly scan
Describe history and exam done at a normal antenatal appointment?
HISTORY:
Physical and mental health
Fetal movements
EXAM: BP and urinalysis Symphysis- fundal height Lie and presentation Engagement of presenting part Fetal heart auscultation
List the 11 conditions checked for at the 20 week anomaly scan? What other conditions are checked for?
anencephaly open spina bifida cleft lip diaphragmatic hernia gastroschisis exomphalos serious cardiac abnormalities bilateral renal agenesis lethal skeletal dysplasia Edwards' syndrome, or T18 Patau's syndrome, or T13
check placenta site
Describe placenta praevia and why it is checked for at anomaly scan?
Placenta praevia is when the placenta is low lying in the uterus and covers all parts of the cervix. In most women as the uterus enlarges the placenta moves out of the way. If low at the 20 weeks scan then need to check again at 32 weeks. If still low then the woman needs C section for safe delivery around 37-38 weeks.
Describe Downs, Edwards and Pataus and what this may mean for the baby?
Downs (T21)- difficult to predict how baby affected
Edwards (T18) and Pataus (T13) likely to be lethal if complete
Describe trisomy risk assessment in first and second trimester?
In first trimester the skin thickness behind the fetal neck (nuchal thickness) is measured. This is measured 11-13+6 weeks and combined with HCG and PAPP A (increased NT = more chance of trisomy)
Second trimester screening can also be done but only for T21
How reliable is the trisomy risk assessment in first trimester?
detects up to 90% T21 with 5% false positive rate
Describe NIPT?
non-invasive prenatal testing detects placental DNA fragments in sample of blood taken from mother and is more accurate than combined test so can be offered to women identified as high risk from the combined test (not offered first because it is more accurate in those already identified as high risk). It is still only a screening test (so can’t offer TOP based on result but stops women who don’t need an invasive diagnostic test from having one)
Describe diagnostic antenatal tests?
these can be done for a range of conditions including T21
Amniocentesis is done after 15 weeks and has a miscarriage rate of < 1%
chorionic villus sampling is done after 12 weeks and has a miscarriage rate of < 2%
Describe screening for maternal anaemia and why it is important?
Need to optimise Hb during pregnancy to reduce risk of life threatening post partum haemorrhage
Iron (most common), folate, B12 all screened at booking and at 28 weeks
Describe rhesus screening and what is given to mothers who are rhesus negative?
Blood group and antibody status should be determined at booking and 28 weeks, to prevent fetal anaemia
Anti D injections can be given to prevent D antibodies forming in Rh neg women, given routinely at 28 weeks and after any sensitising event (TOP, antepartum haemorrhage, invasive procedure, external cephalic version, fall or accident)
anti D is given again after birth if baby is rhesus positive (cord blood is tested)
Describe screening of fetal growth?
Serial measurement of symphysis fundal height (SFH) is recommended at each antenatal appointment from 24 weeks of pregnancy as this improves prediction of SGA neonate
If worried about inaccuracies in measurement (e.g. high BMI, history of fibroids) or worried about low measurements can refer woman for US
What cardiac symptoms may women experience during pregnancy and why?
Many women experience palpitations and SOB due to awareness of physiological sinus tachycardia, ventricular premature/ ectopic beats and increased minute ventilation
What is the most common cause of maternal death in the UK?
cardiac disease
What are the main heart conditions associated with pregnancy causing severe morbidity and mortality?
MI, aortic dissection and peripartum cardiomyopathy
Define peripartum cardiomyopathy? What is a common sign?
This is defined as the development of heart failure at end of pregnancy or in months following delivery where no other cause is found. Orthopnoea is a common sign.
Cardiac conditions should counsel mother against pregnancy?
pulmonary arterial hypertension systemic ventricular dysfunction previous peripartum CM with any residual LV impairment severe mitral stenosis severe symptomatic aortic stenosis aortic root > 4.5 cm in Marfans ascending aorta > 5cm with bicuspid A valve severe aortic coarctation
Describe normal breathlessness in pregnancy?
Very common, up to 75% women and is due to awareness of physiological hyperventilation
more common in the third trimester
worse at rest or when talking, improves with exertion
usually doesn’t limit normal activities
What is the most common chronic medical disorder to complicate pregnancy?
asthma
How does the treatment of asthma compare in pregnancy vs normally?
treatment does not differ in the treatment of pregnant vs non pregnant
exact same
Do asthma drugs cause damage to pregnancy?
no- poorly controlled severe asthma presents a much bigger risk to the fetus than the medication used to treat it
Describe labour and asthma?
should be aiming for a vaginal birth, women should continue inhalers during labour (they do not impair uterine activity or delay the onset of labour)
if women are usually on oral steroids during labour they can be given IV hydrocortisone
What is the most common cause of direct death in pregnancy and puerperium?
PE
The risk of VTE in pregnancy is _______
4-6x higher
Where do most DVTs occur in pregnancy?
85-90% of DVTs occur in the left leg, > 70% of DVTs in pregnancy are ileofemoral (the groin)
The daily risk of VTE is ______ in puerperium compared to antenatal period
5 x
Is measuring d dimers in pregnancy to assess DVT risk useful?
no because they are often naturally raised
What can be used to look for DVT?
compression duplex US
What investigations may be used to look for PE in pregnancy?
CTPA and V/Q scans are both safe and only associated with negligible radiation to the fetus and are safe
Treatment of VTE in pregnancy?
larger doses of LMWH, warfarin should be avoided as it is teratogenic due to its ability to cross the placenta, DOACS are not used in pregnancy
Can warfarin be given in pregnancy?
no it crosses the placenta and is teratogenic
Describe heparin and warfarin use in the postnatal period?
Neither heparin or warfarin are contraindications to breast feeding
can commence warfarin on 5th post natal day
anticoagulant therapy should be continued until at least 6 weeks post natal and at least 3 months post partum
What pregnancy related complications are women with CTD at higher risk of?
miscarriage PET abruption FGR Still birth Pre term labour labour/ delivery complications post natal complications
What treatment related complications are women with CTD at higher risk of?
Teratogenic fetotoxic sepsis diabetes osteoporosis
What disease related complications are women with CTD at higher risk of?
Lupus flare- renal or haematological
APS- arterial or venous thrombosis
Rheumatoid and scleroderma- renal deterioration or pulmonary HT
Define anti-phospholipid syndrome? How can it be diagnosed?
person has antiphospholipid antibodies (most common are anticardiolipin and lupus anticoagulant) and clinical features of the condition
diagnosis: have clinical features plus positive antibodies x 2 , 6 weeks apart
What are some clinical features of antiphospholipid syndrome?
arterial/ venous thrombosis recurrent early pregnancy loss late pregnancy loss usually preceded by fetal growth restriction placental abruption severe early onset pre-eclampsia (PET) severe early onset FGR
Describe management of APS in pregnancy?
No thrombosis/ adverse pregnancy outcome - LDA, maternal and fetal surveillance
Previous thrombosis - if on warfarin stop, start LDA + LMWH (treatment dose)
Recurrent early pregnancy loss - LDA + LMWH (prophylactic dose)
Late fetal loss/ severe PET/ FGR - LDA + LMWH (prophylactic dose)
Which of these drugs are safe in pregnancy which are not safe?
Steroids, Leflunomide, azathioprine, cyclophosphamide, methotrexate?
safe:
steroids
azathioprine
not safe:
leflunamide
methotrexate
cyclophosphamide
Which of these drugs are safe in pregnancy which are not safe?
sulfasalazine, hydroxychloroquine, MMF, penicillamine, gold?
safe:
sulfasalazine
hydroxychlorquine
not safe:
MMF
penicillamine
gold
Which of these drugs are safe in pregnancy which are not safe?
chlorambucil, rituximab, adalimumab, infliximab, entanercept?
safe:
rituximab, adalimumab, infliximab, entanercept
not safe:
chlorambucil
Is aspirin safe in pregnancy? Are NSAIDs safe in pregnancy?
aspirin is safe
NSAIDS are not safe if > 32 weeks
Describe seizure frequency with epilepsy during pregnancy?
For most women seizure frequency is unchanged or improves
Describe the risk to fetus of AEDs vs uncontrolled epilepsy in pregnancy?
the risk to the fetus of uncontrolled seizures is greater than the risks of continuing AED treatment, poorly controlled epilepsy and recurrent seizures are associated with adverse outcomes for the fetus
Describe the risks of birth defects in babies of mothers who take AED?
the overall risk of birth defects in babies of mothers who take AED is around 7% as compared with 3% in women without epilepsy, the risk of polytherapy is more at around 16%
Describe the use of sodium valproate in pregnancy?
Sodium valproate is associated with a higher rate of serious malformations e.g. neural tube defects and long term neurodevelopmental defects e.g. a reduced IQ, increased risk of ASD, increased ADHD risk and should be stopped or substituted if necessary
Describe management of a woman with epilepsy who would like to get pregnant?
counselling before conception is essential, folic acid 5mg/day supplements should be taken before conception and throughout the first trimester, vitamin K should also be taken by women receiving enzyme inducing AEDs in the last 4 weeks before delivery to prevent neonatal haemorrhage, antenatal screening for congenital abnormalities is necessary
Describe breastfeeding and AEDs?
mothers on AEDs can breastfeed although manufacturers won’t guarantee safety but they are most likely fine
Describe labour in women with epilepsy?
most women with epilepsy will have a normal labour and vaginal birth, up to 2.6% will have a seizure, if generalised tonic clonic seizure then maternal hypoxia, fetal hypoxia and acidosis may result
What are three categories of hypertension in pregnancy?
pre-existing, gestational/ PIH and pre-eclampsia
Define pre-existing hypertension?
this is present at the initial booking visit or before 20 weeks or the patient is already taking medication for hypertension
it is the likely diagnosis if hypertension is present early in the pregnancy because PET or PIH are diseases of the second half of pregnancy
Pre-existing hypertension increases the risk of ________________
pre-eclampsia, intra-uterine growth restriction and abruption
Management of pre existing hypertension in pregnancy?
ACEi, ARBS and chlorothiazide agents are associated with congenital abnormalities and should be discontinued. Dietary salt intake should be kept low. Aspirin 75 mg should be given from 12 weeks onwards until birth to women at moderate or high risk of pre eclampsia
oral labetolol is 1st line therapy during pregnancy, second line agents are methyldopa and nifedipine. Target BP at <150 / 80-85, if BP < 160/110 birth shouldn’t be offered before 37 weeks
What are the drugs used for treatment of hypertension in pregnancy?
oral labetolol is 1st line therapy during pregnancy, second line agents are methyldopa and nifedipine.
Management of pre existing hypertension in postnatal period and breast feeding?
ACEi, B blockers and nifedipine are all safe in breastfeeding, Methyldopa should be avoided because of the risk of depression.
Define gestational hypertension/ PIH?
This is defined as BP > 140/90 after 20 weeks gestation in a previously normotensive woman
there is no proteinuria or other features of pre eclampsia
Prognosis of gestational hypertension?
usually resolves within 6 weeks of delivery
____ rate of PIH to pre eclampsia
rate of recurrence is ____
15%
high
Investigations for PIH?
blood tests- FBC, U and E, serum creatinine, calcium, liver biochemistry and LFTs
BP measurements should be done once a week
urine tests for protein to check if pre eclampsia develops
Management of PIH?
treat moderate HT 150-9/ 100-9 with oral labetolol
admission to hospital if BP > 160/110 is required
treatment may be required for several weeks post partum
Explain what pre-eclampsia is?
condition seen after 20 weeks of pregnancy characterised by pregnancy induced hypertension with proteinuria (>0.3 g/ 24hr) and oedema
it is a common obstetric cause of maternal and perinatal death and morbidity
it is a pregnancy specific multi system disorder with unpredictable, variable and widespread manifestations
there is diffuse vascular endothelial dysfunction and widespread circulatory disturbance
Explain the theorised pathophysiology of pre-eclampsia?
- There is thought to be a genetic and/ or environmental predisposition to the development of pre-eclampsia
- Stage 1 involves abnormal placental perfusion due to abnormal trophoblast invasion
- Stage 2 involves the maternal syndrome where the mother responds to the decreased placental perfusion and this is what causes the systemic disease
- There is an imbalance in angiogenic and anti-angiogenic factors which is what causes the widespread endothelial dysfunction and circulatory disturbance
List some risk factors for developing pre-eclampsia?
Age > 40 yo FH Multiple pregnancy BMI > 30 Primiparity previous pre-eclampsia long birth interval hydrops with large placenta hydatiform mole triploidy pre-existing HT renal disease Diabetes of any kind Antiphospholipid syndrome RA Sickle cell
Describe some potential symptoms of pre-eclampsia?
headache visual disturbance epigastric/ RUQ pain nausea and vomiting rapidly progressive oedema
Describe some signs of pre-eclampsia?
hypertension proteinuria oedema abdominal tenderness disorientation SGA intra-uterine fetal death hyper reflexia / involuntary movements / clonus
