Obstetrics Flashcards
What is the complication of maternal hypertension that is to be worried about?
Placental abruption
What are the risk factors of spontaneous abortion?
- Advanced maternal age (> 35 years)
- substance abuse
- TORCH infection
- Thyroid dysfunction
- Pre-existing hypercoagulable states (e.g., SLE, antiphospholipid syndrome
- Foetal risk factors - congenital anomalies, exposure to teratogenic drugs and trauma
Why is presence of foetal movement important?
Reduced fetal movements can represent fetal distress, as a method of fetal compensation to reduce oxygen consumption as a response to chronic hypoxia in utero.
This is concerning, as it reflects risk of stillbirth and fetal growth restriction. It is believed that there may also be a link between reduced fetal movements and placental insufficiency.
When do expectant mothers start to feel foetal movement?
The first onset of recognised fetal movements is known as quickening.
This usually occurs between 18-20 weeks gestation, and increase until 32 weeks gestation at which point the frequency of movement tends to plateau.
Multiparous women will usually experience fetal movements sooner, from 16-18 weeks gestation.
Towards the end of pregnancy, fetal movements should not reduce.
What is considered as reduced foetal movement?
There is no established definition for what constitutes reduced fetal movements (RFM), but the RCOG considers less than 10 movements within 2 hours (in pregnancies past 28 weeks gestation) an indication for further assessment.
What are the risk factors causing reduced foetal movement?
Posture - generally awareness being more prominent during lying down and less when sitting and standing
Distraction - women is distracted
Placental position - Anterior placenta position prior to 28wks may have lesser awareness
Medication - alcohol and sedative medications like opiates or benzodiazepines
Fetal position - Anterior fetal position - movement less noticable
Body habitus- Obese patients are less likely to feel prominent fetal movements
Amniotic fluid volume- Both oligohydramnios and polyhydramnios can cause reduction in fetal movement
Fetal size
Up to 29% of women presenting with RFM have a SGA fetus (small for gestation age)
What is the management if 28wk gestation woman presents with reduced foetal movement?
If past 28 weeks gestation:
- Initially, handheld Doppler should be used to confirm fetal heartbeat.
- If no fetal heartbeat detectable, immediate US should be offered.
- If fetal heartbeat present, CTG should be used for at least 20 minutes to monitor fetal heart rate which can assist in excluding fetal compromise.
- If concern remains, despite normal CTG, urgent (within 24 hours) ultrasound can be used. Ultrasound assessment should include abdominal circumference or estimated fetal weight (to exclude SGA), and amniotic fluid volume measurement
What is the management if 26wk gestation woman presents with reduced foetal movement?
Between 24 and 28 weeks gestation:
a handheld Doppler should be used to confirm presence of fetal heartbeat.
What is the management if 18wk gestation woman presents with reduced foetal movement?
If below 24 weeks gestation, and fetal movements have previously been felt, a handheld Doppler should be used.
What is the period before which foetal movements are to be noticed?
If fetal movements have not yet been felt by 24 weeks, onward referral should be made to a maternal fetal medicine unit.
What are the potential sensitising events for rhesus haemolytic disease? And how is it managed
Anti-D immunoglobulin should be given as soon as possible (but always within 72 hours) in the following situations:
- Termination of pregnancy or evacuation of retained products of conception (ERPC) after miscarriage
- Ectopic pregnancy - (if managed surgically, if managed medically with methotrexate anti-D is not required)
- Vaginal bleeding < 12wks or if heavy
- External cephalic version
- Invasive uterine procedure - amniocentesis or chorionic villus sampling (CVS)
- Intrauterine death
- Delivery - delivery of a Rh +ve infant, whether live or stillborn (Kleihauer test - to test maternal circulation within 2hrs of birth)
- Antepartum haemorrhage
When is the rhesus disease screened for during antenatal care?
Booking and 28 weeks
When is anti-D given to rhesus negative women?
Give anti-D at 28 wks after any bleeding or potentially sensitising event and after delivery if neonate is rhesus positive (28 week and 34 weeks)
How is severity of foetal anaemia in rh haemolytic disease assessed? How is it managed
Doppler of foetal middle cerebral artery
Transfuse if foetus anaemic, deliver if >36wks
How do babies with rhesus haemolytic disease present?
- Neonatal jaundice, anaemia and hepatosplenomegaly - less severe
- oedematous (hydrops fetalis, as liver devoted to RBC production albumin falls)
- heart failure
- kernicterus
What tests are done in rhesus disease?
All babies born to Rh -ve mother should have cord blood taken at delivery for FBC, blood group & direct Coombs test
Coombs test: direct antiglobulin, will demonstrate antibodies on RBCs of baby
Kleihauer test: add acid to maternal blood, fetal cells are resistant
- An indirect Coombs is a screening test that is carried out at booking/28/34 weeks to establish if the mother already has Rh Abs present.
- The Kleihauer is used after a sensitising event to see if fetomaternal haemorrhage has occurred
- The direct Coombs is used to see if the baby has Rh Haemolytic Disease
Who are patients at high risk of developing preeclampsia and how are they managed?
- hypertensive disease during previous pregnancies
- chronic kidney disease
- autoimmune disorders such as SLE or antiphospholipid syndrome
- type 1 or 2 diabetes mellitus
Women who are at high risk of developing pre-eclampsia should take aspirin 75mg od from 12 weeks until the birth of the baby
What is the normal fluctuation of BP observed in pregnancy?
Blood pressure usually falls in the first trimester (particularly the diastolic), and continues to fall until 20-24 weeks
After this time the blood pressure usually increases to pre-pregnancy levels by term
What is the criteria for HTN in pregnancy?
systolic > 140 mmHg or diastolic > 90 mmHg
OR
An increase above booking readings of > 30 mmHg systolic or > 15 mmHg diastolic
What is the criteria for pre-existing hypertension?
A history of hypertension before pregnancy or an elevated blood pressure > 140/90 mmHg before 20 weeks gestation
No proteinuria, no oedema
What is the criteria for gestational hypertension?
Hypertension (as defined above) occurring in the second half of pregnancy (i.e. after 20 weeks) - > 140/90
No proteinuria, no oedema
Resolves following birth (typically after one month). Women with PIH are at increased risk of future pre-eclampsia or hypertension later in life
What are the principal RFs for pre-eclampsia
Moderate risk:
- Nulliparity
- Previous preeclampsia
- Family history
- Multiple gestation (twins)
- Chromosomal anomalies or congenital structural anomalies
- Hydatidiform moles
- old maternal age - 40 years or older
- Pregnancy interval of more than 10 years
- Body mass index (BMI) of 35 kg/m² or more at first visit
High risk:
- hypertensive disease during previous pregnancies
- chronic kidney disease
- autoimmune disorders such as SLE or antiphospholipid syndrome
- type 1 or 2 diabetes mellitus
What are the features of severe pre-eclampsia?
hypertension: typically > 170/110 mmHg and proteinuria as above
proteinuria: dipstick ++/+++ (300mg in 24h / urine protein:creatinine ratio - 0.3 )
headache
visual disturbance
papilloedema
RUQ/epigastric pain
hyperreflexia
platelet count < 100 * 106/l, abnormal liver enzymes or HELLP syndrome
What are the blood investigation findings in pre-eclampsia?
FBC: Relative ↑ Hb due to haemoconcentration (due to oedema – more fluid stay in interstitial space!) , Thrombocytopenia, Anaemia (if haemolysis)
Coagulation - mildly prolonged PT and APTT
Biochemistry: ↑ Urate ↑ Urea & Creatinine Abnormal LFTs (↑ transaminases) ↑ Lactate dehydrogenase (LDH – a marker for haemolysis) ↑ Proteinuria (>300mg protein/24h)