Obstetrics Flashcards
What are the risks of asymptomatic bacteriuria in pregnancy?
Increased risk of preterm delivery
Increased risk of pyelonephritis during pregnancy
How should asymptomatic bacteriuria be treated?
Immediate antibiotic prescription (nitrofurantoin, amoxicillin or cefalexin)
Which tests are done at the booking visit?
FBC
MSU
Blood group and antibody screen
Infection screen (Hep B, HIV, Syphilis)
When does gestational thrombocytopaenia tend to occur?
> 28 weeks
What should women with a history of GDM be offered in their pregnancy?
OGTT or random blood glucose in the 1st trimester
NOTE: helps identify pre-existing diabetes that has developed in the meantime
How should newborns born to women with hepatitis B be treated to reduce the risk of transmission?
Hepatitis B vaccine (at birth, 1 month and 6 months)
Hepatitis B immunoglobulin
NOTE: both should be given within 12 hours
Which parameters are used to date the pregnancy on ultrasound scan?
10-14 weeks = CRL
14-20 weeks = Head Circumference
What are the components of the combined test for Down syndrome?
Nuchal translucency
b-hCG
PAPP-A
What are the components of the quadruple test for Down syndrome?
b-hCG AFP Unconjugated oestriol Inhibin A NOTE: the triple test is a similar test that doesn't use inhibin A
What should be offered to women with a high risk of Down syndrome according to initial screening tests?
CVS (10-14 weeks)
Amniocentesis (15+ weeks)
cffDNA (only available privately)
NOTE: results take 48 hours
How often should SFH be measured?
Every antenatal appointment after 24 weeks
What should happen if there are concerns about foetal growth according to SFH measurements?
Organise an ultrasound
What is the NICE recommendation regarding vitamin D during pregnancy?
All pregnant and breastfeeding women should receive 10 µg vitamin D daily
When should an OGTT be performed in women with a high risk of GDM?
24-28 weeks
If previous history of GDM, this should be done at 16-18 weeks and a repeat at 24-28 weeks
What should be offered to women with a history of late pregnancy loss and a short cervix?
Prophylactic vaginal progesterone
Prophylactic cervical cerclage
How should PPROM be investigated?
Sterile speculum - pooling observed –> diagnose PPROM
No pooling –> test for IGF-like binding protein-1 and alpha-microglobulin-1 test
IMPORTANT: diagnostic tests should NOT be performed if the patient goes into labour
What antibiotic prophylaxis should be given to patients with PPROM?
Oral erythromycin 250 mg QDS for 10 days or until the woman is in established labour
Which women should be offered rescue cervical cerclage?
16-27 weeks with a dilated cervix and unruptured membranes
Do NOT perform if signs of infection, active vaginal bleeding or uterine contractions
Which investigations should be used to confirm a diagnosis of preterm labour?
If suspected preterm labour > 30 weeks
- Consider TVUSS to determine likelihood of birth within 48 hours (cervical length > 15 mm means it is unlikely)
- Consider fetal fibronectin (low concentration suggests it is unlikely)
IMPORTANT: if < 30 weeks and clinical assessment suggests preterm labour, treatment is necessary without further investigation
Which agent is most commonly used for tocolysis?
Nifedipine
If contraindicated: atosiban (oxytocin receptor antagonist)
Up to what gestation should maternal corticosteroids be considered in preterm labour?
36 weeks
Which agent is used for neuroprotection in preterm delivery?
IV magnesium sulphate 4 g IV over 15 mins (loading) and 1 g/hour until birth or for 24 hours
NOTE: this is used in women who are delivering at 24-34 weeks (most important for 24-30 weeks)
How is magnesium sulphate poisoning treated?
Calcium gluconate
Which parameters are measured in ultrasound biometry used to monitor foetal growth?
Biparietal diameter
Head circumference
Abdominal circumference
Femur length
How should IUGR babies be monitored?
Serial growth scans every 2 weeks
Doppler can be done 2 times per week (looks out for placental dysfunction leading to absent/reversal of blood flow in umbilical artery)
Advise monitoring foetal movements
ADMIT if reduced foetal movements
Which antihypertensives are associated with congenital abnormalities?
ACE inhibitors
ARBs
NOTE: these are not safe when breastfeeding (neither is amlodipine)
What level of urinary protein: creatinine ratio is considered significant?
> 30 ng/mmol
Which agent is used to treat gestational hypertension?
Oral labetalol
What should the target blood pressure be in gestational hypertension?
Systolic: < 150
Diastolic: 80-100
When should blood pressure be measured in a woman with gestational hypertension who has just given birth?
Daily for the first 2 days
Once on day 3 and 5
Continue the use of antihypertensives but consider reducing the dose as the BP falls < 140/90 (same applies for PET)
How often should blood pressure be measured in women who have been admitted for pre-eclampsia?
At least 4 times per day
Which other tests should you perform in a woman with pre-eclampsia?
FBC
U&E
LFTs
Foetal: USS, Doppler US, CTG
After how many weeks would you consider delivery for a woman with pre-eclampsia?
Within 24-48 hours for women with pre-eclampsia > 37 weeks
NOTE: this can be even earlier depending on the severity and response to treatment
How often should blood pressure be measured postnatally in a woman who has had pre-eclampsia?
At least 4/day whilst an inpatient
At least once on days 3 and 5
On alternate days thereafter if the results aren’t normal on days 3/5
NOTE: if blood pressure remains > 150/100, start an anti-hypertensive
When should methyldopa be stopped after birth?
Within 2 days after birth
When should further scans to assess the foetus be carried out in women with hypertensive disease in pregnancy?
28-30 weeks
Repeat at 32-34 weeks if severe pre-eclampsia
NOTE: CTG should be performed for any reported reduced foetal movements
What does magnesium sulphate toxicity cause and how is it treated?
Respiratory depression
Treatment: calcium gluconate
How long should magnesium sulphate be continued for in a woman with pre-eclampsia?
For 24 hours after the last seizure or until 24 hours after delivery
List some clinical features of severe pre-eclampsia?
Severe headache Visual disturbance Severe pain just below the ribs Papilloedema Signs of clonus Liver tenderness HELLP syndrome Platelet count falling below 100 x 109/L Abnormal liver enzymes
What should be monitored whilst giving magnesium sulphate treatment?
Reflexes
Respiratory rate
Oxygen saturation
Urine output
ECG monitoring is required during and for 1 hour after loading dose
What is the recurrence rate of gestational hypertension?
16-47%
What is the recurrent race of pre-eclampsia?
16%
What are the blood glucose targets fo a patient with diabetes mellitus in pregnancy?
Fasting < 5.3 mmol/L
1-hour post-prandial < 7.8 mmol/L
2-hour post-prandial < 6.4 mmol/L
NOTE: if on insulin or glibenclamide, recommend maintaining BM > 4
How often should pregnant women with diabetes mellitus check their blood glucose?
7 times per day
How do insulin requirements change throughout pregnancy?
Insulin resistance changes through pregnancy so patients are likely to require an increase in the dose of metformin or insulin in the second half of pregnancy
Which extra screening tests/monitoring would be recommended for women with diabetes during pregnancy?
Renal and retinal screening
Serial ultrasound for foetal growth and amniotic fluid volume (every 4 weeks from 28-36 weeks)
Assessment of cardiac outflow tracts at 20-week anomaly scan
How should blood glucose be managed in a patient with T1DM or T2DM on insulin during labour?
Sliding scale or insulin and glucose
Aim for blood glucose 4-7 mmol/L
What are the risks that pregnancy carries in a woman with diabetes?
Blood glucose control is more important
Increased insulin requirements
Increased risk of hypoglycaemia
Risk of deterioration of pre-existing retinopathy and nephropathy
What are the risks of diabetes for a pregnancy?
Miscarriage Congenital malformation Macrosomia Pre-eclampsia Stillbirth Infection Operative delivery
Aside from blood glucose control, which other medications should be recommended for women with diabetes during pregnancy?
5 mg folate preconception until 12 weeks
75 mg aspirin from 12 weeks until delivery
Who should review a woman with a new diagnosis of GDM and when should this happen?
Joint diabetes and antenatal clinic within 1 week of diagnosis
Outline the management options for gestational diabetes mellitus.
1) diet and exercise (provided fasting BM < 7)
2) metformin (if step 1 ineffective after 1-2 weeks)
3) add insulin
If fasting BM > 7 –> insulin
If fasting BM 6-6.9 and evidence of complications (e.g. macrosomia) –> insulin
When should women with GDM check their blood glucose on a daily basis?
Fasting
Pre-meal
1-hour post-meal
Bedtime
When might HbA1c be used in pregnancy?
In all women with pre-existing diabetes at booking
At the time of diagnosis of GDM to identify undiagnosed T2DM
When should women with diabetes in pregnancy ideally deliver?
Offer elective birth between 37-39 weeks
How should a woman with GDM be followed-up postnatally?
Stop blood glucose lowering treatment immediately
If BM returns to normal:
- Offer lifestyle advice
- Offer fasting plasma glucose at 6-13 weeks (or HbA1c thereafter) to exclude diabetes
What is an alternative agent that can be used in diabetes in pregnancy is metformin is not tolerated?
Glibenclamide (sulphonylurea)
What are the steps in the management of a patient with hyperemesis gravidarum?
1st line: antihistamines (promethazine or cyclizine)
2nd line: ondansetron or metoclopramide
Alternative: P6 acupressure, ginger
If severely dehydration: admit for IV rehydration, thiamine supplementation and thromboprophylaxis
What antibiotic regime is recommended for UTI in pregnancy?
Nitrofurantoin 50 mg QDS for 7 days
2nd line: amoxicillin or cephalexin
What TSH level should pregnant women with hypothyroidism aim for?
< 4 mmol/L
What are the risks of suboptimal thyroid hormone replacement?
Developmental delay
Pregnancy loss
How should hyperthyroidism in pregnancy be treated?
Lowest possible dose of propylthiouracil (or carbimazole)
WARNING: risk of agranulocytosis
What are the risks of uncontrolled thyrotoxicosis in pregnancy?
Miscarriage
Preterm delivery
IUGR
What are the three criteria required to diagnose postpartum thyroiditis?
< 12 months of giving birth
Clinical manifestations of hypothyroidism
TFTs to support
NOTE: TPO antibodies present in 90%
How is post-partum thyroiditis managed?
Thyrotoxic phase: propanolol
Hypothyroid phase: thyroxine
What happens to the pituitary gland during pregnancy?
Enlarges by 50%
NOTE: dopamine agonists are usually stopped during pregnancy
What measures are taken in labour for a woman with heart disease?
Aim to wait for spontaneous labour
Epidural anaesthesia usually recommended (reduces pain-related stress/increase in CO)
Prophylactic antibiotics (if structural heart defect)
Use syntocinon judiciously
Consider instrumental delivery to keep second stage short
Avoid supine position
Which asthma drugs are safe to use in pregnancy?
ALL of them
Which medications that are commonly used in labour/delivery should be avoided in asthmatic patients?
Ergometrine
Prostaglandin F2a
Labetalol
What congenital abnormalities are associated with anti-epileptic drug use in pregnancy?
Neural tube defects
Facial clefts
Cardiac defects
Others: developmental delay, growth restriction
What is the dangerous consequence of a seizure during pregnancy?
Maternal and foetal hypoxia
How might the recommendations for delivery be different in a pregnant woman with epilepsy?
Recommend epidural analgesia because it reduces stressors that might precipitate an epileptic seizure
NOTE: women should also receive vitamin K in the last month of pregnancy if on phenytoin
Which antiepileptic is considered to carry the lowest risk of congenital malformations?
Lamotrigine
NOTE: breastfeeding is considered safe with antiepileptics
How are migraines managed in pregnancy?
Simple analgesia
Consider low-dose aspirin and beta-blockers to prevent attacks
NOTE: triptans are contraindicated
Which treatments can be used to increase platelet count in ITP in pregnancy?
Steroids
IVIG
NOTE: platelet count > 50 x 10^9/L is required for safe delivery, > 70 x 10^9 is necessary for epidurals
What are the risks associated with untreated coeliac disease in pregnancy?
Spontaneous miscarriage
IUGR
List some comorbid conditions that require 5 mg folic acid preconception to 12 weeks in pregnancy.
Diabetes mellitus Coeliac disease Epilepsy (i.e. antiepileptic drug use) Obesity Thalassemia
Which investigations should be requested in suspected obstetric cholestasis?
LFTs
Bile acid
Coagulation screen (PT may be prolonged due to reduced vitamin K)
What are the main risks of obstetric cholestasis?
Prematurity
Stillbirth
Meconium passage
How should obstetric cholestasis be treated?
Advise wearing loose cotton clothes
Ursodeoxycholic acid
Vitamin K supplementation (if PT prolonged)
Topical emollients
Offer induction at 37 weeks
Offer weekly LFTs and twice weekly CTG (and close monitoring of foetal movements)
How long before getting pregnant should methotrexate be stopped?
3 months
Until what point in pregnancy can NSAIDs be used?
32 weeks
Outline the reassuring features of a CTG.
BRA: 110-160
V: > 5 bpm
A: present
D: none
Outline the non-reassuring features of a CTG.
BRA: 161-180, 100-109
V: < 5 bpm
A: absence with an otherwise normal trace
D: variable decels with over 50% of contractions occurring over 90 mins, single prolonged decel for up to 3 mins
Outline the pathological features of a CTG.
BRA: > 180, < 100
V: < 5 bpm for 90 mins
A: atypical variable decelerations with over 50% of contractions or late decels, both for > 30 mins
D: single prolonged decel for > 3 mins
What is the difference between a suspicious and a pathological trace?
Suspicious: 1 non reassuring feature
Pathological: 2 non reassuring features OR 1 pathological feature
Which investigation can help confirm fetal distress after a suspicious CTG?
Foetal blood sampling
This is only done if the patient is at 8-9 cm and you want reassurance that you can continue
What are the features of congenital rubella syndrome?
o Sensorineural deafness o Congenital cataracts o Blindness o Encephalitis o Endocrine problems
Describe the relationship between the gestation at which a pregnant woman develops rubella and the risk to the foetus.
< 11 weeks = nearly 100% risk
> 20 weeks = no risk
< 16 weeks = offer termination of pregnancy
What advice would you give to Rubella IgG negative pregnant women?
Keep away from anyone that might have rubella
Offer MMR vaccine in the postnatal period
What are the consequences of syphilis in pregnancy?
o FGR o Foetal hydrops o Congenital syphilis (may cause long-term disability) o Stillbirth o Preterm birth o Neonatal death
How should syphilis in pregnancy be treated?
Benzathine penicillin (parenteral)
NOTE: if the woman is not treated during pregnancy, treat the child after delivery
What is the difference between non-treponemal and treponemal tests for syphilis?
Non-treponemal tests are non-specific screening tests that detect non-treponemal antibodies
Treponemal tests detect specific treponemal antibodies and are more specific
Name two non-treponemal tests.
Rapid plasma reagin (RPR)
Venereal disease research laboratory (VDRL)
Name two treponemal tess.
EIA
Treponema pallidum haemagglutination assay (TPHA)
NOTE: these are used in pregnancy
What is a Jarish-Herxheimer reaction?
Treatment results in the release of proinflammatory cytokines in response to dying organisms
Presents with symptoms and fever that develops 12-24 hours after treatment
What advice can you give a pregnant woman about avoiding toxoplasmosis?
Avoid eating raw/rare meat
Avoid handling cats and cat litter
How is a diagnosis of toxoplasmosis made?
Sabin Feldman dye test
Which test should be performed if an ultrasound suggests that there is a risk of congenital toxoplasmosis?
Amniocentesis and PCR of amniotic fluid for T. gondii
If toxoplasmosis is found to be the cause of the abnormal ultrasound, TOP should be offered
NOTE: treated with spiramycin
What are the clinical features of congenital toxoplasmosis?
Ventriculomegaly Microcephaly Chorioretinitis Cerebral calcification NOTE: most infants are asymptomatic at birth
Describe the relationships between the gestation at which the mother is exposed to toxoplasmosis and the risk fo foetal damage.
1st trimester - most likely to cause severe foetal damage but the risk of transmission is low
3rd trimester - low risk of foetal damage but much higher transmission rates
Why is the detection of IgM antibodies not very useful for toxoplasmosis and CMV?
They persist for a long time so you don’t know when the patient was infected
How can IgM antibodies be used to confirm a diagnosis of CMV in a pregnant woman?
A new finding of anti-CMV IgM in a previously IgM-negative woman is suggestive of primary CMV infection
How can a diagnosis of CMV infection in pregnancy be confirmed?
Amniocentesis and PCR
If congenital CMV is detected, offer TOP
How can VZV immunity be confirmed?
Detection of VZV IgG
How should you treat non-immune women who have been exposed to chickenpox?
VZIG as soon as possible given up to 10 days after contact
Seek advice if rash develops
What are the maternal risks of VZV in pregnancy?
Increased risk of pneumonia, hepatitis and encephalitis
How is chickenpox in pregnancy managed?
Avoid contact with other pregnant women and infants
Oral aciclovir for 7 days should be prescribed if presenting within 24 hours of rash onset and > 20 weeks gestation (consider in patients < 20 weeks)
If hospitalised, keep in isolation
How should maternal chickenpox around the time of delivery be managed?
Significant risk to the newborn if within 4 weeks of delivery
Elective delivery should be avoided until 7 days after the onset of the rash (allow time for Abs to pass)
Arrange neonatal ophthalmic examination at birth
If birth within 7 days of maternal rash or the mother develops chickenpox within 7 days of delivery, give VZIG to the neonate
Neonatal infection should be treated with aciclovir
Monitor for signs of infection until 28 days after maternal infection onset
What are the main features of congenital varicella syndrome?
Skin scarring in a dermatomal distribution
Eye defects (microphthalmia, chorioretinitis, cataracts)
ypoplasia of the limbs
Neurological abnormalities
What prenatal diagnosis techniques can be offered to a woman with chickenpox in pregnancy?
Refer to foetal medicine specialist at 16-20 weeks or 5 weeks after infection
Amniocentesis and VZV DNA PCR has a high NPV but low PPV
What is the main risk of parvovirus B19 infection in pregnancy?
Aplastic anaemia leading to hydrops fetalis and intrauterine death
May resolve spontaneously or may need intrauterine blood transfusion
At what point in pregnancy does parvovirus B19 infection pose the greatest risk to the foetus?
< 20 weeks
What are the risks of listeria in pregnancy?
Stillbirth
Late miscarriage
Early-onset sepsis
How is listeria treated?
IV antibiotics (ampicillin 2 g every 6 hours and erythromycin)
How should first-episode genital herpes in pregnancy be diagnosed and treated?
Refer to GUM
Viral culture and PCR
Aciclovir 400 mg TDS
How should women with primary herpes infection in the 3rd trimester be managed?
C-section should be recommended (especially if within 6 weeks of onset)
Give intrapartum IV aciclovir
How should recurrent episodes of herpes simplex infection in pregnancy be managed?
NOT an indication for C-section
Consider oral aciclovir from 36 weeks
Avoid invasive procedures if there are genital lesions
How would you manage a woman who is found to have GBS in her genital tract?
Intrapartum antibiotics (IV benzylpenicillin) as soon as possible after the onset of labour
Penicillin allergy: clindamycin
List some indications for GBS prophylaxis.
Intrapartum fever
PROM
Prematurity
Previous infant with GBS
Incidental detection of GBS in pregnancy
GBS bacteriuria
NOTE: women colonised with GBS who are having an elective C-section do NOT need GBS-specific antibiotic cover
Outline the management of the newborn with risk factors for early-onset GBS disease.
1 minor risk factor = remain in hospital for observation for 24 hours
2 or more minor risk factors = full septic screen AND IV penicillin + gentamicin
How should HIV be monitored in pregnancy?
CD4 at baseline and at delivery
Viral load every 2-4 weeks, at 36 weeks and after delivery
What interventions can be used to reduce the risk of transmission of HIV to the baby?
ART (antenatally and intrapartum in the mother, in the baby for 4-6 weeks)
Delivery by C-section if the viral load is high
Avoidance of breastfeeding
When would C-section be recommended for women with HIV in pregnancy?
Hepatitis C coinfection
High viral load > 50
What antiretroviral cover is recommended for pregnant women undergoing a planned C-section or presenting with SROM?
IV zidovudine (4 hours before C-section)
How are neonates born to mothers with HIV treated?
Clamp the cord ASAP
Bath the baby
Avoid breastfeeding
AZT (oral or IV) for 4-6 weeks
How can HIV infection in the newborn be confirmed?
Direct viral amplification by PCR
Usually carried out at birth, 2 weeks, 6 weeks and 12 weeks
Last one at 18 months
How often should vaginal examination be performed in the first stage of labour?
Every 4 hours
When does the active phase of the 1st stage start?
When the cervix is 4 cm dilated and fully effaced
What counts as a prolonged second stage of labour?
Nulliparous > 2 hours since onset of active 2nd stage
Multiparous > 1 hour since onset of active 2nd stage
Allow an extra hour if they have epidural analgesia