According to the RCOG Guidance, it is 39%

CTPA delivers a low radiation dose to the fetus

With Remifentanyl PCA- Respiratory depression is reported in up to 32% of patients and
oxygen saturations below 90% are seen in about 5%.

Some suggested contraindications of Remifentanyl PCA include- morbid obesity, clinical features of a chest infection and primigravida women who are at risk of prolonged labour.

• Clinicians should consider the use of intravenous tranexamic acid (0.5–1.0 g), in addition to oxytocin, at caesarean section to reduce blood loss in women at increased risk of PPH.
• Consideration should be given to the use of tranexamic acid in the management of PPH.
• According to a Cochrane review- blood loss greater than 400 or 500 ml was less
  common in women who received tranexamic acid in addition to the usual uterotonic agent after vaginal
  birth or caesarean section in a dosage of 1 or 0.5 g intravenously. Tranexamic acid was effective in
  decreasing the incidence of blood loss greater than 1000 ml in women who had undergone caesarean section but not vaginal birth. Further studies are required to investigate the risk of serious adverse effects, including thromboembolic events.

If accidental dural puncture occurs with an epidural needle there is a 70–80% chance of a postdural puncture headache

In women at very high risk of thrombosis , UFH may be used peripartum in
preference to LMWH where there is an increased risk of haemorrhage or where regional anaesthetic techniques may be required.

The contraindications/Cautions are-

• Known bleeding disorder (e.g. haemophilia, von Willebrand’s disease or acquired coagulopathy)
• Active antenatal or postpartum bleeding
  - Women considered at increased risk of major haemorrhage (e.g. placenta praevia)
  - Thrombocytopenia (platelet count < 75 × 109/l)
  - Acute stroke in previous 4 weeks (haemorrhagic or ischaemic)
  - Severe renal disease (glomerular filtration rate [GFR] < 30 ml/minute/1.73m2)
  - Severe liver disease (prothrombin time above normal range or known varices)
  - Uncontrolled hypertension (blood pressure > 200 mmHg systolic or > 120 mmHg diastolic)
•  ( In case of any doubt, a haematologist review should be sought)