Differential Diagnosis of Breathlessness in Pregnancy
| Diagnosis | Key features | Management |
|---|---|---|
| Physiological breathlessness of pregnancy | Gradual onset in 2nd/3rd trimester. Worse on talking. | Exclude pathology and reassure. |
| Anaemia | Physiological haemodilution means anaemia is defined as Hb <105g/L. | Exclude serious pathology. Check iron status. Iron supplements as required. |
| Cardiorespiratory causes | ||
| Asthma | As in non-pregnant, but pregnancy may exacerbate the condition. Reflux can also exacerbate or mimic asthma symptoms. | Manage acute exacerbation as with non-pregnant patient (Chapter 60). Ensure compliance with prescribed medications. |
| Pneumonia | As in non-pregnant; however, some organisms are associated with particularly severe disease, for example H1N1, VZV. | As for non-pregnant. Lower threshold for admission. If VZV pneumonitis suspected – IV acyclovir. If delivery is within ten days – neonate needs ZIG. |
| Pneumothorax | Associated with the valsalva of second stage of labour. | Chest radiography. |
| Pulmonary embolus | ∼5-fold increase risk in pregnancy. ∼ 25-fold increase risk immediately postnatal. Sudden onset CP and breathlessness. Signs of right heart strain. Classical clinical features of DVT are much less common in pregnancy therefore need high index of suspicion. | CXR, ECG, ABG. Make the diagnosis with available imaging. (Q scan or CTPA). Anticoagulate with LMWH. Consider IV heparin or thrombolysis if cardiovascular instability. Involve obstetricians with timing of delivery. |
| Pulmonary oedema | Rare but often missed. Associated with pre-eclampsia or peripartum cardiomyopathy. | If clinical suspicion, get urgent ECG, CXR and Echo. Off load with diuretics and liaise with obstetricians regarding timing and management around delivery. |
| Peripartum cardiomyopathy | Most common in 1st month after delivery in older, multiparous black women. | As per pulmonary oedema. |
| Pulmonary hypertension | Rare but is associated with 25% mortality in pregnancy; therefore needs to be excluded. | Refer to specialist pulmonary hypertension centre. |
| Heart valve disease | MS can present for the first time in pregnancy (usually in 2nd trimester) with breathlessness/palpitations, tachyarrhythmia, pulmonary oedema or stroke. | ECG, CXR, Echo. Treat failure, anticoagulate if in AF, β-blockers once failure treated. Liaise with obstetricians for management plan for delivery. |
| Other causes | ||
| Amniotic fluid embolus | See chest pain/shock. | See chest pain/shock |
| Metabolic | Starvation ketoacidosis in 3rd trimester presents with breathlessness and often a short history of vomiting. | ABGs, ketones. Give glucose. Treat cause of vomiting. Re-establish oral intake. |
MS, mitral stenosis.