Obstetrics Flashcards
How many antenatal appointments for a nulliparous woman?
10
How many antenatal appointments for a parous woman?
7
What is done at the booking visit?
Full obstetric history FGM screen Height and weight, BMI Urinalysis for proteinuria Urine MC+S for asymptomatic bacteriuria Booking bloods
What blood tests are in the booking bloods?
FBC Haemoglobinopathies and Red Cell Alloantibodies ABO blood group and Rhesus status Hepatitis B Rubella, Syphilis, Chickenpox serology HIV test is offered
What is offered on the Combined test?
Nuchal transluceny
beta-HCG
Pregnancy associated plasma protein A (PAPP-A)
Combined (and extra) findings in Down’s Syndrome
Thickened nuchal translucency Increased beta HCG Low PAPP-A Low Oestriol Low alpha Fetoprotein
How should dating scan be made if CRL is >84mm
Use head circumference
If the placenta is praevia on Foetal anomaly scan, when should another scan be offered?
32 weeks
Most low-lying placentas will have resolved by then
What is done at routine antenatal visits?
BP
Urine dip for proteinuria
SFH measurement from 24 weeks
Which visits are only for nulliparous women?
25 weeks
31 weeks
40 weeks
When is Anti-D offered?
28 and 34 weeks
or sensitising events
When should External Cephalic Version be offered?
36 weeks (primip) 37 weeks (multip)
Sensitising events to Rh -ve mothers?
Delivery Amniocentesis Chorionic villus sampling Foetal blood sampling External cephalic version Miscarriage > 12 weeks Surgically managed ectopic pregnancy Termination of pregnancy Antepartum Haemorrhage
When is amniocentesis performed?
15-20 weeks
When is chorionic villus sampling performed?
11-14 weeks
Risks of Amniocentesis/ CVS
Pain/ discomfort Infection Miscarriage Inadequate result Needing anti-D prophylaxis
Clinical signs of pregnancy
Amenorrhoea Nausea and vomiting Chadwick sign (blue vaginal discolouration) Hegar sign (Cervical softening) Skin pigmentation Palpable uterus 6-12 weeks
Time frame of usual nausea and vomiting in pregnancy
Begins 4 weeks
Most ended 16-20 weeks
Treatment of non-complicated nausea and vomiting
Ginger
P6 wrist acupuncutre
Antihistamines e.g. Chlorphenamine
Risk factors for hyperemesis gravidarum
Obesity Nulliparity Hyperthyroidism Multiple pregnancy Trophoblastic disease
Protective factors for hyperemesis gravidarum
Smoking
Anti-emetic therapy for hyperemesis gravidarum
1st, 2nd and 3rd line?
Cyclizine/ Promethazine are 1st line
Metoclopramide or Ondansetron 2nd line
Corticosteroids reserved for severe cases
Complications of hyperemesis gravidarum
Wernicke's encephalopathy Mallory-Weiss tear central pontine myelinolysis acute tubular necrosis Increased VTE risk fetal: small for gestational age, pre-term birth
How to diagnose obstetric cholestasis vs normal itching?
Raised AST/ALT
Alk phos is raised normally in pregnancy- unreliable marker
Management of itching and obstetric cholestasis
Topical emollients and steroids
Ursedeoxycholic acid
Delivery is only cure
Symptoms of symphysis pubis dysfunction
Difficulty walking
Weight bearing problems
Limited/ painful hip abduction
Lying/ sitting position discomfort
Therapies for leg cramps in pregnancy
Sodium chloride
Calcium
Quinine
Definition of SGA
Foetus less than 10th centile for weight or other Biophysical parameter
Severe if < 3rd centile
Major risk factors for SGA
Maternal age 40+ Smoking 11+ daily Cocaine Maternal or paternal SGA Previous SGA baby/ stillbirth PAPP-A <0.4 MoM Chronic hypertension Antiphospholipid syndrome Diabetes Renal impairment
Minor risk factors for SGA
Maternal age 35+ IVF singleton pregnancy Nullipartiy BMI under 20 BMI 25-34 Low fruit intake Previous pre-eclampsia
Investigations for SGA if 1 major criteria:
Serial USS and umbilical artery doppler from 26-28 weeks
Investigations for SGA if 3 minor criteria:
Assess foetal size and umbilical artery doppler in 3rd trimester
Management/ delivery in SGA
Delivery at 37 weeks
32 weeks if severe
34 weeks if static growth over 3 weeks
Administer steroids
Which cause of Large for Gestational Age (LGA) babies is associated with Amoxicillin use in pregnancy?
Hydrops fetalis
Most common type of IUGR
Asymmetrical (70% of cases)
Occurs later in pregnancy
Head sparing pattern
Low SC fat, risk of hypoglycaemia and hypoxia
Maternal death
Death within 42 days of end of pregnancy
Direct causes of maternal death
Obstetric complications or resulting from interventions/ omissions/ incorrect treatments
Indirect causes of maternal death
Previously existing disease or disease developed during pregnancy
At which point should RFM be investigated for neuromuscular conditions?
24 weeks
Name of practice contractions that occur prior to labour
Braxton-Hicks contractions
Investigations of PPROM and pre-term labour
Bloods (FBC, CRP) Urine dip and MSU CTG Cervical swabs for GBS Placental alpha-Microglobulin-1 test
Why is a TVUS performed in suspected pre-term labour
If Cervical length < 15 mm at 30+0 weeks, this is diagnostic of pre-term labour
Why is foetal fibronectin used as a test for pre-term labour
Its not normally detectable in vaginal secretions before 36 weeks
Positive if greater than 50ng/ml
Drugs used in pre-term labour
Erythromycin 250mg QDS 10 days for chorioamnionitis prophylaxis
Nifedipine- Tocolysis, allows steroid administration
Steroids before 34 weeks e.g. Betamethasone
Magnesium sulphate before 34 weeks- neuroprotective
What do steroids help protect against in pre-term labour?
Respiratory distress syndrome
Peri-ventricular leukomalacia
Rules for delivery in pre-term labour
Vaginal OK if cephalic
No foetal scalp electrode use before 34 weeks
Delayed cord-clamping
Preventing preterm labour
Vaginal progesterone or cervical cerclage treatment
- Women with hx of spontaneous birth/ mid-trimester loss between 16 and 34 weeks
- TVUS shows a cervical length < 25mm between 16 and 24 weeks
When does a DCDA twin form?
Before day 3
When does a MCDA twin form?
Between days 4-8
When does a MCMA twin form?
Days 9-13
When do conjoined twins form?
After day 13
What signs suggest multiple pregnancy?
Increased membrane thickness and T sign on USS
Uterus large-for-dates
Increased hyperemesis incidence
How frequently are growth scans performed in multiple pregnancy?
4-weekly in Dichorionic
2-weekly in Monochorionic
When are DCDA twins delivered?
37 weeks
When are MCDA twins delivered?
36 weeks
When are MCMA twins delivered?
32-34 weeks
Potential causes of GDM
Increased physiological demands in pregnancy
Human Placental Lactogen production
Less renal tubular reabsorption
Risk factors for GDM needing screening
BMI 30+ Previous macrosomic baby 4.5kg 1st degree family history Ethnicity Glycosuria at antenatal visit
Diagnosis of GDM
2 hour 75g OGTT used at 24-28 weeks
- 7.8mmol/L (2 hour glucose)
OR
5.6mmol/L fasting glucose
Major/ Greatest risk factors for Antenatal VTE prophylaxis
Hospital Admission Previous VTE related to major surgery High Risk Thrombophilia e.g. F5 Leiden Medical co-morbidity Surgical procedure Ovarian Hyperstimulation Syndrome
Which medical co-morbidities are considered high-risk for antenatal VTE prophylaxis?
Cancer Heart failure SLE IBD/ Inflammatory polyarthropathy Nephrotic syndrome Sickle cell disease Current IVDU
What are the minor individual risk factors for antenatal VTE prophylaxis which may require treatment?
BMI 30+ Age 35+ Parity 3+ Smoker IVF Varicose veins Current pre-eclampsia Immobility 1st degree family history of unprovoked VTE Multiple pregnancy