A 35-year-old woman was presented at the hospital with breathlessness for past three days.She is 34 weeks pregnant in her third pregnancy. Prior to this pregnancy, she had an emergency caesarean section for abnormal cardiograph in labour, followed by a 7-week miscarriage. In this week, she was hoping for vaginal delivery.The ultra sound scans and blood tests were normal. History She describes her shortness of breath when she was at work and slightly worsen since. She felt particularly breathless when she ran to catch a bus on her way home and has left side chest pain on breathing in. There is no cough or haemoptysis.

She has had no previous episodes . She has also not noted any calf pain but has left leg swelling and some back pain. Examination The women do not look obviously unwell. Blood pressure 127/78 mm Hg and heart rate 98/min. Oxygen saturation percent is 96. Chest examination…