complicated pregnancy Flashcards
define foetus lie
foetus relative to the longitudinal axis of the uterus.
types of lie
longitudinal lie (99.7% of foetuses at term)
transverse lie (<0.3% of foetuses at term)
oblique (<0.1% of foetuses at term)
define transverse lie
foetal head is on the lateral side of the pelvis and the buttocks are opposite. When in transverse lie, the foetus can be either ‘scapulo-anterior’ (most common) where the foetus faces towards the mother’s back or ‘scapulo-posterior’ where the foetus faces towards the mothers front.
RFs of transverse lie
- Most commonly occurs in women who have had previous pregnancies
- Fibroids and other pelvic tumours
- Pregnant with twins or triplets
- Prematurity
- Polyhydramnios
- Foetal abnormalities
diagnosis of trasnverse lie
- Abnormal foetal lie will be detected during routine antenatal appointments with a midwife during abdominal examination.
- Abdominal examination: the head and buttocks are not palpable at each end of the uterus. The foetus can be felt to be lying directly across the uterus.
- Ultrasound scan: allows direct visualisation of the foetal lie. Foetal heart rate is also auscultated to assess for distress.
complications of transverse lie
- Pre-term rupture membranes (PROM)
- Cord-prolapse (20%)
- If allowed to progress to vaginal delivery, compound presentation may occur. This is extremely rare in the UK.
Mx of transverse lie before 36 weeks of gestation
no management required. The patient should be informed that most foetuses will spontaneously move into longitudinal lie during pregnancy.
Mx of tranverse after 36 weeks of gestation
the patient must have an appointment with the obstetric medical antenatal team to discuss management options:
Mx options
Active management: perform external cephalic version (ECV) of the foetus. This can be performed late in pregnancy and even early labour if the membranes have not yet ruptured. ECV should be offered to all women who would like a vaginal delivery.
Contraindications include maternal rupture in the last 7 days, multiple pregnancy (except for the second twin) and major uterine abnormality. Success rate is around 50%
Elective caesarian section: this is the management for women where the patient opts for caesarian section or ECV has been unsuccessful or is contraindicated.
The decision to perform caesarian section over ECV will be based on the perceived risks to the mother and foetus, the preference of the patient, the patient’s previous pregnancies and co-morbidities and the patient’s ability to access obstetric care rapidly.
most commonest explanation for short episodes <40 mins of decreased variability on CTG
foetus is asleep
if decreased variability lasts for more than 40 minutes
start to worry
other causes of decreased variability in foetal heart rate on CTG
- due to maternal drugs (such as benzodiazepines, opioids or methyldopa - not paracetamol)
- foetal acidosis (usually due to hypoxia), prematurity (< 28 weeks, which is not the case here)
- foetal tachycardia (> 140 bpm, again not the case here)
- congenital heart abnormalities.
what does a CTG do
measures fetal heart rate and uterine contractions.
records pressure changes in the uterus using internal or external pressure transducers
what is baseline bradycardia
bradycardia Heart rate < 100 /min
causes of baseline bradycardia
increased fetal vagal tone
maternal beta-blocker use
what is baseline tachycardia
Heart rate > 160 /min
causes of baseline bradycardia
Maternal pyrexia, chorioamnionitis,
hypoxia
prematurity
what is loss of baseline variability
< 5 beats / min
causes of baseline variabiltiy
prematurity
hypoxia
what is early deceleration
Deceleration of the heart rate which commences with the onset of a contraction and returns to normal on completion of the contraction
causes of early deceleration
Usually an innocuous feature and indicates head compression
what is late deceleration
Deceleration of the heart rate which lags the onset of a contraction and does not returns to normal until after 30 seconds following the end of the contraction
causes of late deceleration
Indicates fetal distress e.g. asphyxia or placental insufficiency
what is variable decelerations
independent of contractions
causes of variable decelerations
cord compression
nmeonic for CTGs
DR C BRA VADO
DR- define risk: why is this patient on a CTG monitor? e.g. pre-eclampsia, antepartum haemorrhage, maternal obesity, maternal ill health
C- contractions. Look at the bottom of the trace, each contraction is shown by a peak. In established labour you would expect 5 contractions in 10 minutes. Each large square = 1 minute duration, so count the number of contractions in 10 squares.
BRA- baseline rate. The fetal baseline rate should be approximately 110-160 beats per minute. Each large square = 10 beats and each small square = 5 beats.
A fetal bradycardia is below 110 beats per minute and a fetal tachycardia is above 160 beats per minute.
V- baseline variability. The fetal heart rate should vary between 5 to 25 beats per minute. Below 5 beats per minute, the variability is said to be reduced.
A- accelerations. Are there accelerations in fetal heart rate? Accelerations are a rise in fetal heart rate of at least 15 beats lasting for 15 seconds or more. There should be 2 separate accelerations every 15 minutes. Accelerations typically occur with contractions.
D- decelerations. Are there decelerations in fetal heart rate? These are a reduction in fetal heart rate by 15 beats or more for at least 15 seconds. Decelerations are generally abnormal and should prompt senior review. In particular, late decelerations, which are slow to recover are indicative of fetal hypoxia.
O- overall impression/diagnosis.
terminal bradycardia and terminal decelerations.
A terminal bradycardia is when the baseline fetal heart rate drops to below 100 beats per minute for more than 10 minutes.
A terminal deceleration is when the heart rate drops and does not recover for more than 3 minutes. These make up a ‘pre-terminal’ CTG and are indicators for Emergency Caesarean section.
what is factor V leiden
inherited condition in which Factor V is resistant to degradation by activated Protein C predisposing individuals to develop clots
high risk factor for VTE
previous history of VTE Hospital admission Surgical procedures Previous VTE Medical conditions such as cancer or arthritis High-risk thrombophilias Ovarian hyperstimulation syndrome
intermediate risk factors of developing VTE
hospitilisation
surgery
co-morbidities
thrombophilia
risk factors in general that increase risk of developing VTE
Age > 35 Body mass index > 30 Parity > 3 Smoker Gross varicose veins Current pre-eclampsia Immobility Family history of unprovoked VTE Low risk thrombophilia Multiple pregnancy IVF pregnancy
how many risk factors required to warrant an immediate treatment AND Mx
4 or more first trimester
LMWH based on weight
stopped during labour
LMWH - enoxaparin, dalteparin and tinzaparin
start prophylaxis at 28 weeks three RFs or more and continued until six weeks postnatal
Mechanical prophylaxis may be considered in women with contraindications to LMWH. The options for mechanical prophylaxis are:
Intermittent pneumatic compression with equipment that inflates and deflates to massage the legs
Anti-embolic compression stockings
high risk 6 weeks after
intermediate 10 days after
if diagnosis of DVT is made shortly before delivery what do u o
continue anticoag treatment for at least 3 months
which anticoag treatmsent should be avoided
DOACs and warfarin
what is TTTS twin-to-twin transfusion syndrome
relatively common complication of monochorionic twin pregnancies.
pathology of TTTA
two fetuses share a single placenta, meaning that blood can flow between the twins. In TTTS, one fetus, the ‘donor’ receives a lesser share of the placenta’s blood flow than the other twin, the ‘recipient’. This is due to abnormalities in the network of placental blood vessels. The recipient may become fluid-overloaded whilst the donor can become anaemic. One fetus may have oligohydramnios and the other may have polyhydramnios as a result of differences in urine production, causing additional problems. In severe cases, TTTS can be fatal for one or both fetuses.
When does TTTS usually occur
early or mid-pregnancy, thus ultrasound examinations performed between 16 and 24 weeks focus on detecting this condition. After 24 weeks the main purpose of ultrasound examinations is to detect fetal growth restriction.
what is the purpose of having regular US after 24 weeks in monochorionic
fetal growth restriction
what is the purpose of having regular US between 16- 24 weeks in monochorionic pregnancy
detect TTTS
classification twins
dizygotic (non-identical, develop from two separate ova that were fertilized at the same time
Monozygotic (identical, develop from a single ovum which has divided to form two embryos)
monoamniotic monozygotic is associated with
- increased spontaneous miscarriage, perinatal mortality rate
- increased malformations, IUGR, prematurity
- twin-to-twin transfusions: recipient is larger with polyhydramnios (do laser ablation of interconnecting vessels)
predisposing factors for dizygotic twins
- previous twins
- family history
- increasing maternal age
- multigravida
- induced ovulation and in-vitro fertilisation
- race e.g. Afro-Caribbean
antenatal complications in twin pregnancies
- polyhydramnios
- pregnancy induced hypertension
- anaemia
- antepartum haemorrhage
fetal complication in twin pregnancies
- prematurity (mean twins = 37 weeks, triplets = 33)
- light-for date babies
- malformation (*3, especially monozygotic)
labour complications in twin pregnancies
Postpartum haemorrhage increase
malpresentation
cord prolapse, entanglement
Mx of twin pregnancies
- rest
- ultrasound for diagnosis + monthly checks
- additional iron + folate
- more antenatal care (e.g. weekly > 30 weeks)
- precautions at labour (e.g. 2 obstetricians present)
- 75% of twins deliver by 38 weeks, if longer most twins are induced at 38-40 wks
presentation of DVT
examination
unilateral Calf or leg swelling Dilated superficial veins Tenderness to the calf (particularly over the deep veins) Oedema Colour changes to the leg
examination
eg swelling measure the circumference of the calf 10cm below the tibial tuberosity. More than 3cm difference between calves is significant.
presentation of PE
Shortness of breath
Cough with or without blood (haemoptysis)
Pleuritic chest pain
Hypoxia
Tachycardia (this can be difficult to distinguish from the normal physiological changes in pregnancy)
Raised respiratory rate
Low-grade fever
Haemodynamic instability causing hypotension
VTE and C section
LMWH for 10 days after delivery
if elective then look at RFs
Ix for DVT and PE
DVT doppler US recommends repeating negative ultrasound scans on day 3 and 7 in patients with a high index of suspicion for DVT.
DO NOT DO D-DIMER AS ITS NATURALLY ELEVATED
PE - chest x-ray, ECG
definitive diagnosis - CTPA, VQ
Mx options of PE
Unfractionated heparin
Thrombolysis
Surgical embolectomy
