Obstetrics Flashcards
What can happen during pregnancy to chronic medical problems?
Worsen/flare
What pre-existing disorders may worsen during pregnancy?
Asthma
Epilepsy
Thyroid
Renal
Diabetes
Cardiac
SLE
Rheumatoid arthritis
Name 3 pregnancy specific disorders
Pre-eclampsia/eclampsia
Obstetric cholestasis
Gestational diabetes
Acute fatty liver (rare)
Thromboembolism
Mental health disorders
What is important in the management of pre-existing medical conditions in pregnancy?
Be familiar with normal physiological changes of pregnancy
Preconception assessment
Effect of pregnancy on medical condition
Effect of medical condition of the pregnant woman and her baby - including impact of maternal medication
MDT at all stages
What should you do pre-pregnancy for women with pre-existing condition?
Optimise disease control
Defer pregnancy until medical condition is stable
Rationalise drug therapy to minimise effects of baby - alter medication to drugs safe in pregnancy
Advise on risks to mum and baby
Agree a plan of care - MDT
Effective contraception until ready to conceive
Name a condition that may worsen during pregnancy
Mitral stenosis
Name a condition that may improve during pregnancy
Rheumatoid arthritis
What effect might the medical disorder have on the pregnancy?
Increased risk of pregnancy complications
eg essential hypertension/renal disease -> risk of superimposed pre-eclampsia
What effect might the medical disorder have on the foetus?
Teratogenic drug effects
Premature delivery
How are women with pre-existing medical conditions cared for in the antenatal period?
Obstetrician with expertise in medical problems and physician with expertise in pregnancy +/- nurse/midwife specialist
Improved communication
Reduced hospital visits for the woman with co-ordinated care
Facilitates audit and research
What is important to be put in place if necessary before a woman with pre-existing medical condition delivers?
Safest mode of delivery
Neonatal support
Anaesthetic expertise
HDU/ITU facilities
Ongoing postpartum care - maternal condition may initially deteriorate
What is the definition of anaemia?
Haemoglobin < 105gm/L
Why are pregnant women more likely to get anaemia?
Increased iron requirement in pregnancy (2-3 fold) and folate (10-20 fold)
What is the most common type of anaemia in pregnancy?
Iron deficiency
Followed by folate deficiency
What is anaemia in pregnancy associated with?
Low birthweight and preterm delivery
How is asthma affected by pregnancy?
Increased metabolic rate and O2 consumption (20%)
Increased minute ventilation due to tidal volume - respiratory rate unchanged
Increased arterial pO2 and decreased pCO2 decrease -> mild compensated respiratory alkalosis in pregnancy
What is important in asthma before pregnancy?
Optimise control
When is the risk of asthma exacerbation highest in pregnancy?
Third trimester
What is the leading cause of maternal death?
Cardiac disease
What needs to be done with women with pre-existing cardiac disease?
Joint care with cardiologist
Ideally with pre-pregnancy assessment
How is the heart affected during pregnancy?
Cardiac output rises by 40% mainly due to increased stroke volume
What cardiac problems are low risk in pregnancy?
Mitral incompetence
Aortic incompetence
ASD
VSD
What cardiac problems are high risk in pregnancy?
Aortic stenosis
Coarctation of aorta
Prosthetic valves
Cyanosed patients
What are the key aspects of management of cardiac problems in pregnancy?
Pre-pregnancy assessment -> risk of complications/death
Pregnancy/postpartum care -> prediction and prevention of heart failure - echo/ECG
Anticoagulation -> mechanical heart valves
Drug therapy -> need to alter/add medication
Monitor foetal growth and wellbeing -> scan
Timing and mode of delivery and postpartum complications
How common is obstetric cholestasis?
Commonest liver disease in pregnancy
Genetic predisposition - more prevalent in Scandinavia and Chile
How does obstetric cholestasis present?
Presents with itching - no rash
Abnormal liver function - raised AST, ALT and bile acid
What is the recurrence risk of obstetric cholestasis?
Recurrence risk > 80%
What are the risks to the foetus in obstetric cholestasis?
Stillbirth/premature birth
How is obstetric cholestasis treated?
Ursodeoxycholic acid -> does not reduce foetal complications but improves biochemical abnormalities
What happens with hyperthyroidism during pregnancy?
Often improves in pregnancy after first trimester
What is the risk to the mother with hyperthyroidism?
Thyroid crisis with cardiac failure
What is the risk to the foetus with hyperthyroidism?
Thyrotoxicosis due to transfer of thyroid stimulating autoantibodies
What is important to monitor in mothers with hyperthyroidism?
Foetal growth if mother has stimulating antibodies
What medication should be used to treat hyperthyroidism during pregnancy and why?
Propylthiouracil (maternal liver failure) over carbimazole (foetal abnormalities)
What happens with untreated hypothyroidism in pregnancy?
Early foetal loss and impaired neurodevelopment
How should you manage hypothyroidism in pregnancy?
Aim for adequate replacement with thyroxine especially in first trimester
What is gestational diabetes?
Carbohydrate intolerance first recognised in pregnancy
How should you manage a women pre-conception with diabetes?
HbA1c < 48mmol/L
Folic acid 5mg
Stop ACEi and statins
Retinal screening
Check renal function and microalbuminuria
What are the maternal complications of diabetes?
DKA
Pre-eclampsia
Progression of retinopathy
Hypoglycaemia
What are the foetal complications of diabetes?
Miscarriage
Foetal abnormality
Still birth
Premature labour
Macrosomia -> shoulder dystocia
Neonatal hypoglycaemia, hypocalcaemia and polycythaemia
Respiratory distress
Most complications due to maternal hyperglycaemia
Why do babies get macrosomia in mothers with diabetes?
Insulin -> growth factor -> macrosomia
How can you treat diabetes in pregnancy?
Insulin
Metformin
All other hypoglycaemics contraindicated
Statins and ACEi contraindicated
Why are pregnant women more at risk of UTIs?
Urinary tract dilates in pregnancy secondary to progesterone -> predisposing to ascending infection and acute pyelonephritis and renal stones
What happens to renal function during pregnancy?
50% increase in renal blood flow and GFR
Serum creatinine, urate, and albumin fall
What are the maternal complications of chronic renal disease?
Severe hypertension
Superimposed pre-eclampsia
Deterioration of renal disease
C-section
What are the foetal complications of chronic renal disease?
Foetal malformations secondary to drugs
Intrauterine growth restriction
Stillbirth
Prematurity
How should chronic renal disease in pregnancy be managed?
Pre-pregnancy risk assessment
MDT care
Close monitoring of renal function and blood pressure during pregnancy
Regular assessment of foetal growth and wellbeing
How common are migraines during pregnancy?
1:5
How common is epilepsy during pregnancy?
1:150
How common is MS during pregnancy?
1:1000
How common is eclampsia during pregnancy?
1:2000
How common is cerebral vein thrombosis during pregnancy?
1:2500-10000
How common is MG during pregnancy?
1:25000
How common are malignant brain tumours during pregnancy?
1:50000
What are the maternal complications of epilepsy?
Increase in seizure frequency 25-35%
Sudden unexpected death in epilepsy - mainly in women who don’t take medication
What are the foetal complications of epilepsy?
Risk of foetal abnormality due to meds and epilepsy itself
Inheritance of epilepsy
Risk of foetal hypoxia with maternal seizures
What is important to remember with anti-epileptic treatment during pregnancy?
All anti-epileptics associated with risk of foetal abnormalities
Sodium valproate highest risk
What can sodium valproate during pregnancy lead to?
Neural tube defect
ASD
Cleft palate
Hypospadias
Polydactyly
Craniosynestosis
Learning difficulties
Autism
How should you manage epilepsy during pregnancy?
○ Preconception assessment
High dose folic acid
Rationalise medication
Once pregnant - offer screening for foetal anomalies
Control seizures
Plan for delivery - pain relief, avoid prolonged labour
Postpartum support
What can increase your risk of VTE in pregnancy?
Increased maternal age, BMI, operative delivery
How do you investigate a suspected VTE?
Doppler USS +/- V/Q scan +/- CTPA
How do you treat a VTE in pregnancy?
LMWH
Warfarin and other anticoagulants CI
What is a premature infant?
Born before…
37 weeks
259 days from LMP
245 days after conception
What is the definition of a LBW infant?
<2500gm at birth regardless of GA
VLBW < 1500gm
ELBW < 1000gm
What improvements have there been in neonatal intensive care?
Antenatal steroids
Artificial surfactant
Ventilation
Nutrition
Antibiotics
How common are spontaneous preterm deliveries?
70% preterm deliveries
When might a preterm delivery be indicated?
Medial/obstetric disorders 30%
What can increase your risk of a preterm delivery?
No apparent risk factor in 50%
Non-recurrent
- APH, other vaginal bleeding
- Multiple pregnancy
Recurrent
- Race
- Previous preterm birth
- Genital infection
- Cervical weakness
- Socioeconomics
What infections can increase the risk of pre-term birth?
Genital - bacterial vaginosis (x2 risk)
Non-genital
- UTI
- Pyelonephritis
- Appendicitis
What treatment can be given in bacterial vaginosis to reduce risk of preterm birth?
Rx with metronidazole and erythromycin may reduce rate of SPTB
What primary prevention strategies are there to prevent preterm birth?
Reducing population risk
Effective interventions not demonstrable yet - Smoking and STD prevention
- Prevention of multiple pregnancy
- Planned pregnancy
- Variable work schedules
- Physical and sexual activity advice
- Cervical assessment at 20-26 weeks
What secondary prevention strategies are there to prevent preterm birth?
Select increased risk for surveillance and prophylaxis
Transvaginal cervical USS for cervical length
Qualitative foetal fibronectin test
What is the qualitative foetal fibronectin test?
Extracellular matrix protein found in choriodecidual interface
Abnormal finding in cervicovaginal fluid after 20 weeks - may indicate disruption of attachment of membranes to decidua
Reappears close to term as labour approaches
False +ve - cervical manipulation, sexual intercourse, lubricants, bleeding
What tertiary prevention strategies can be put in place to prevent premature birth?
Treatment after diagnosis
Aim to reduce morbidity/mortality
Prompt dx and referral
Drugs - tocolysis, antibiotics
Corticosteroids
What hormone has been shown to prevent premature birth?
Recent studies suggest benefit women at high risk
How is preterm labour diagnosed?
Persistent uterine activity and change in cervical dilatation and/or effacement
What are the treatment principles of preterm labour?
Identify associated cause, treat if possible
Assess foetal maturity
Consider tocolysis and give steroids
Decide best route of delivery
Plan with neonatologists and in best place, consider in utero transfer
How common is hypertension in pregnancy?
Complicates 7-10% pregnancies
- 70% gestational hypertension/pre-eclampsia - eclampsia
- 30% chronic hypertension
How common is eclampsia?
Eclampsia 0.05% incidence
20% maternal deaths
10% preterm births
What causes eclampsia?
Aetiology unknown
What can predispose you to eclampsia?
Primigravida
Young female x3 increased risk
Black x2 increased risk
Multifoetal pregnancies
Hypertension
Renal disease
Collagen vascular disease
Diabetes
What is gestational hypertension?
New HT after 20 weeks
Systolic > 140 diastolic > 90
No or little proteinuria
How many people with gestational hypertension will develop pre-eclampsia?
25%
What is the definiction of pre-eclampsia?
New HT after 20th week (earlier with trophoblastic disease)
Increased BP (gestational BP elevation) with proteinuria
- Systolic > 140 diastolic > 90
- Proteinuria > 0.3g protein/24 hr
- > 2+ on urine dip
What is eclampsia?
Features of pre-eclampsia plus generalised tonic-clonic siezures
What is chronic hypertension?
Hypertension diagnosed before pregnancy, before 20th week gestation, during pregnancy and not resolved postpartum
How do you diagnosed pre-eclampsia superimposed on chronic hypertension/renal disease?
Chronic hypertension - HT and no proteinuria < 20 weeks, new onset proteinuria > 20 weeks
Renal disease - HT and proteinuria < 20 weeks
- Sudden increase in proteinuria
- Sudden increase in BP when HT well controlled
- Thrombocytopenia < 100,000
- Abnormal ALT/AST
What is severe pre-eclampsia?
One or more
- BP > 160 systolic, > 110 diastolic
- Proteinuria > 5gm/24hr, over 3+ urine dip
- Oligouria < 400ml in 24hr
- CNS - visual changes, headache, scotomata, mental status chage
- Pulmonary oedema
- Epigastric or RUQ pain
- Impaired LFTs
- Thrombocytopenia < 100,000
- Intrauterine growth restriction
- Oligohydramnios
What is the pathology of pre-eclampsia/eclampsia?
Failure of conversion of spiral arteries to vascular sinuses -> placental ischaemia -> foetal growth retardation and placenta produces thromboplastins causing DIC, renin causing vasoconstriction -> poor renal perfusion, hypertension, proteinuria, oedema -> pre-eclampsia
What happens if pre-eclampsia goes untreated?
Poor renal perfusion, hypertension, proteinuria, oedema -> eclampsia
How is maternal pre-eclampsia characterised?
Vasospasm
Activation of coagulation system
Derangement in humoural and autocoid control of blood volume and pressure
Oxidative stress and inflammatory-like responses
Ischaemia from poor placentation
What happens to the kidneys in pre-eclampsia?
GFR and renal blood flow decrease
Raised uric acid levels
Proteinuria
Hypoclaciuria - alterations in regulatory hormones
Impaired Na excretion and suppression of renin-angiotensin system
What happens to the coagulation system in pre-eclampsia?
Thrombocytopenia, low antithrombin III, higher fibronectin
What happens to the liver in pre-eclampsia?
HELLP syndrome - Haemolysis, Elevated ALT and AST (Liver enzymes), Low Platelets
What happens in the CNS with pre-eclampsia?
Headache and visual disturbances
Scotomata
Cortical blindness
Eclampsia
What are the symptoms of pre-eclampsia?
Visual disturbances
Headache similar to migraine - N&V
Epigastric pain - hepatic swelling and inflammation, stretch of liver capsule
+/- oedema
Rapid weight gain
Physical findings
- BP
- Proteinuria
- Retinal vasospasm or oedema
- RUQ abdominal tenderness
- Brisk/hyperactive reflexes common
- Ankle clonus - neuromuscular irritability that raises concern
What are the possible differential diagnoses of pre-eclampsia?
TTP
Haemolytic uraemic syndrome
Acute fatty liver of pregnancy
What lab tests can you do for pre-eclampsia?
Haemoglobin, platelets
Serum uric acid
LFTs
If 1+ protein by clean catch dip stick - timed collection for protein and creatinine
Accurate dating and assessment of foetal growth
What is the goal of pre-eclampsia treatment?
Prevent eclampsia and other severe complications
Palliate maternal condition to allow foetal maturation and cervical ripening
When should you hospitalise someone with pre-eclampsia?
New-onset to assess maternal and foetal conditions
Pre-term onset of severe gestational hypertension or pre-eclampsia
What are the maternal indications for delivery in pre-eclampsia?
Gestational age 38 weeks
Platelet count < 100,000 cells/mm3
Progressive deterioration in liver and renal function
Suspected abruptio placentae
Persistent severe headaches, visual changes, nausea, epigastric pain, or vomiting
Favourable cervix
Delivery based on maternal and foetal conditions as well as gestational age
What are the foetal indications for delivery in pre-eclampsia?
Severe foetal growth restriction
Non-reassuring foetal testing results
Oligohydramnios
What is the cure for pre-eclampsia?
Delivery
Always beneficial for mother
Deleterious for baby
What is the preferable route of delivery in pre-eclampsia?
Vaginal preferable
Labour induction (usually within 24 hours)
Neuraxial (epidural, spinal, and combined) techniques offer advantages
Hydralazine/labetalol pretreatments to reduce hypertension during delivery
MgSO4 - for seizures in delivery and brain ripening for baby
What anti-convulsive therapy can you give to women with eclampsia?
Parenteral magnesium sulphate reduces frequency of eclampsia and maternal death
How do you treat acute severe hypertension in pregnancy?
Parenteral hydralazine and labetalol (avoid in women with asthma and CHF)
Oral nifedipine used with caution
Sodium nitroprusside
What is acute severe hypertension?
SBP > 160 and/or DBP > 105
What post-partum counselling should you give to women who had pre-eclampsia?
Counselling for future pregnancies
What can increase the risk of recurrent pre-eclampsia?
Pre-eclampsia < 30 weeks
New father
Black
What is the puerperium?
From delivery of placenta to 6 weeks following birth
Return to pre-pregnant state
Initiation/suppression of lactation
What physiological changes occur during the puerperium?
Endocrine changes
Involution of uterus and genital tract
Lochia rubra
Lochia serosa
Lochia alba
Breast changes
What endocrine changes occur during the puerperium?
Profound decrease in serum levels of placental hormones (human placental lactogen, hCG, oestrogen, progesterone)
Increase of prolactin
What changes occur in the uterus and genital tract during the puerperium?
Muscle - ischaemia, autolysis, and phagocytosis
Decidua - shed as lochia, rubra, serosa, alba
When is the lochia rubra and what happens during it?
Day 0-4
Blood
Cervical discharge
Decidua
Foetal membrane
Vernix
Meconium
When is the lochia serosa and what happens during it?
Day 4-10
Cervical mucus
Exudate
Foetal membrane
Micro-organisms
White blood cells
When is the lochia alba and what happens during it?
Day 10-28 Cholesterol
Epithelial cells
Fat
Micro-organisms
Mucus
Leukocytes
What breast changes occur during the puerperium?
Establishment of lactation
At birth presence of colostrum
Lactogenesis
- Prolactin - milk production
- Oxytocin - milk ejection reflex
Lactation suppression 7-10 days
What are the health benefits of breast feeding in women?
Reduced breast cancer
What are the health benefits of breast feeding for babies?
Reduction in 4 acute conditions in infants - gastrointestinal disease, respiratory disease, otitis media, necrotising enterocolitis
What is lactoferrin?
Multifunctional protein in milk