OHCS Flashcards
(166 cards)
What is the treatment for pre-eclamptic seizures?
ABCDE
Call for senior help
Magnesium sulfate is the evidence-based treatment for eclamptic seizures.
- 4g IV over 5-10min then 1g/h for 24hrs
- Treat further fits with 2g bolus
- Stop if RR <12, tendon reflex loss, or urine output <20mL/h)
- —Have calcium gluconate ready if RR depression
Monitor
- Catheterise for hourly urine output
- HR, BP, RR, SpO2 every 15min
- FBC, U+Es, LFTs, creatinine and clotting every 12-24hrs
This patient also needs to have her blood pressure controlled carefully and delivery expedited.
What are the risk factors for gestational diabetes?
When do you test?
BMI >30
Previous baby >4.5kg
1st-degree relative diabetic
Family origin from areas of high risk
Screen (75g glucose tolerance test) at 28 weeks
-16 and 28 weeks if previous GDM.
What tests do you carry out at the booking visit?
Hb, blood group and antibody screen (Rhesus)
Syphilis, rubella (+/- chickenpox) serology
HBsAg and HIV test
Sickle test depending on family origin
Hb electrophoresis
25-Hydroxyvitamin D if relevant
Take an MSU (protein; bacteria)
If from an endemic area for TB or a TB contact perform Mantoux test and CXR
Offer screening for chromosomal and structural abnormalities
What are the risk factors for pre-eclampsia?
How do you determine who needs prophylaxis?
High risk:
- Previous severe or early onset pre-eclampsia (<20 weeks)
- Chronic hypertension or hypertension of previous pregnancy
- CKD
- DM
- Autoimmune (SLE, antiphospholipid, thrombophilia
Moderate risk
- 1st pregnancy
- 40 or older
- Pregnancy interval of over 10 years
- FH of pre-eclampsia
- Multiple pregnancy
- Low PAPP-A
- Uterine artery notching on doppler US at 22-24 weeks
(if 1 high risk or 2 moderate risk factors take aspirin 75mg PO OD from 12th week until delivery
How do you manage pre-eclampsia?
Mild = BP 140-149/90-99 and urine PCR >30mg/mmol
- 4 hourly BP
- Check bloods 3 times per week
- Fortnightly Renal function, LFTs, FBC
- Fortnightly fetal growth scans
Moderate = BP 150-159/100-109
- Admit to hospital until delivery
- Same monitoring as above plus twice-daily CTG
- Start antihypertensives (IV labetolol (1st) PO nifedipine (2nd) or hydralazine)
Severe = >160/110 or symtpoms/signs or end organ damage
- Call for seniors
- Control BP (aim for under 150/100)
- Plan delivery in next 24-48hrs (steroids etc) if >34 weeks
Magnesium sulphate is given during labour and in first 24hrs after birth to prevent seizures.
How do you manage preterm rupture of membranes (PROM)?
Admit for 48hrs (80% go into labour)
Rule out chorioamnionitis and sepsis
- Temperature
- MSU
- High vaginal swab using bivalve speculum
Give corticosteroids and erythromycin 500mg PO QDS for 10 days
If labour does not occur discharge after 48hrs and manage as out patient
- Avoid intercourse, tampons and swimming
- Weekly follow up in day unit
- Aim for induction of labour after 34 weeks if cephalic
What is fetal fibronectin?
Protein not usually detected in vaginal secretions between 22 and 36 weeks.
Used to rule out preterm labour and is a bedside test
Those with +ve have 10% chance of preterm delivery and should be admitted and given corticosteroids
False +ve’s = intercourse, speculum, a significant bleeding or vaginal exam within 48hrs
What is the definition of small for gestational age?
Estimated fetal weight <10th centile for their gestational age or abdominal circumference <10th centile
What are the major and minor risk factors of small for gestational age?
Major
- Maternal age >40
- Smoker, Cocaine use
- Previous SGA baby
- Previous stillbirth
- Maternal/paternal SGA
- Chronic hypertension, DM, Renal impairment
- Antiphospholipid syndrome
- Pre-eclampsia
- Low PAPP-A
Minor
- Maternal age >35
- Nulliparity
- BMI <20
- IVF
- Pregnancy induced hypertension
Which women should be assessed by serial US dopplers?
Women who have a major risk factor should be referred for serial ultrasound measurement of fetal size and assessment of wellbeing with umbilical artery Doppler from 26–28 weeks of pregnancy
Women who have three or more minor risk factors should be referred for uterine artery Doppler at 20–24
weeks of gestation
What is involved in the combined test?
NT
Free human chorionic gonadotrophin
Pregnancy-associated plasma protein (PAPP-A)
Woman’s age
Used between 11 and 13+6 weekds
What is involved in the quadruple test?
Dating scan (not NT scan) Woman's age
4 blood tests:
- Maternal AFP
- Unconjugated estriol
- free BhCG or total BhCG
- Inhibin A
Use between 15+0 weeks and 20+0 weeks
What is chorionic villus biopsy?
Carried out at 10-12 weeks
Placenta is sampled by transabdominal or occasionally transcervical approach under continuous US control.
Karyotyping takes 2 days, enzyme and gene probe analysis 3 weeks, so termination for abnormality is earlier, safer, and is done before the pregnancy is apparent, compared with amniocentesis
Risks are:
-excess miscarriage rate of 1-2%, increased transmission of blood-borne viruses (HIV, hep B and C), rarely contamination by maternal cells
What is amniocentesis?
Undertaken from 16 weeks onwards and involves the aspiration of fluid containing fetal cells shed from skin and gut.
A small needle is passed transabdominally under continuous US, preferably not transplacentally
Fetal loss rate is around 1% at 16 weeks gestation.
AntiD needed in all Rh -ve women
Advantages over CVS/CVB:
- Able to diagnose fetal infections such as CMV
- Excess miscarriage rate lower
Full cell culture for karyotyping may take as long as 3 weeks, but rapid results are possible within 2 days by FISH and PCR.
How can you shorten the 3rd stage of labour and reduce the incidence of PPH?)
When is this contraindicated?
Syntometrine (ergometrine maleate 500mcg IM and oxytocin 5u IM) as the anterior shoulder is born
It can precipitate MI and is contraindicated in:
- Pre-eclampsia
- Severe hypertension
- Severe liver or renal impairment
- Severe heart disease
(if BP not measured in labour give just oxytocin)
When do you carry out fetal blood sampling?
How do you act on result?
What if you cant do it?
Used to detect fatal hypoxia after abnormal CTG
-Don’t bother taking if immediate delivery required
Normal = repeat in 1h if CTG remains abnormal
- pH >7.25
- Lactate 4.1 mmol/l or below
Borderline = repeat in 30min if CTG remains abnormal
- pH 7.21-7.24
- lactate 4.2 to 4.8 mmol/l
Abnormal pH <7.2 = Immediate delivery
- pH <7.2 or
- Lactate 4.9 mmol/l or above.
If FBS fails then the baby should be delivered ASAP
What should you advise women considering a vaginal birth after cesarean (VBAC)?
Risk of uterine rupture is 0.5% (1:200)
72-75% of VBACs are successful
How do you manage shoulder dystocia?
Gentle downward traction fails to deliver shoulder
Call for help
CONSIDER episiotomy
-can make internal manoeuvres easier but not always necessary
Discourage pushing as this impacts the shoulders even more
Place in McRoberts (hyperflexed lithotomy) position
-Successful 90% of time
Suprapubic pressure
Enter the pelvis for internal manoeuvres
Roll mother onto all fours if this fails
LAST LINE
-Zavanelli (yeet baby back in and go for CS
How do you investigate a mother who reports decreased foetal movements?
A handheld Doppler will, in most cases, confirm the presence of a fetal heartbeat. This is widely available in most settings. If the fetal heartbeat is not confirmed, then immediate referral for an ultrasound scan to assess fetal cardiac activity is required.
After viability has been confirmed, if the woman still complains of reduced fetal movement, then a CTG should be performed. If she continues to complain of reduced fetal movements, and despite having a normal CTG, then a detailed ultrasound scan should be undertaken.
What is the most accurate test for prenatal testing of trisomies?
Cell-free DNA analysis
Non-invasive investigation of maternal blood
Pretty fucking amazing. Not on NHS yet
Women with uncomplicated pregnancies should be offered induction of labour when?
Women with uncomplicated pregnancies should be offered induction of labour at 4 weeks. After 42 weeks, if a woman declines induction, then the health of the fetus should be monitored.
She should be offered at least twice-weekly CTG and ultrasound estimation of the maximum amniotic pool depth. These best monitor fetal distress and placental function.
What is the classification of perineal tears?
● first degree: injury to the perineal skin only
● second degree: injury to the perineum involving the perineal muscles, but not the anal sphincter
● third degree: injury to the perineum involving the anal sphincter complex, consisting of the external anal sphincter (EAS) and internal anal sphincter (IAS):
● 3a: less than 50% of EAS thickness torn
● 3b: more than 50% of EAS thickness torn
● 3c: both EAS and IAS torn
● fourth degree: injury to the perineum involving the anal sphincter complex (EAS and IAS) and anal epithelium.
What are the risk factors for perineal tears?
Primiparity Large baby (>4kg) Occiput posterior position Induction Epidural use Prolonged second stage Forceps use Midline episiotomy
What drugs increase the successful rate of external cephalic version?
Women should be counselled that, with a trained operator, about 50% of ECV attempts will be successful.
ECV success rates are increased by the use of tocolysis. The drugs shown to be effective include ritodrine, salbutamol, and terbutaline.