In general, pregnant women with symptoms suggestive of an AIDS-defining illness should be managed and investigated in the same way that they would be if they were not pregnant. Lymph node biopsy, liver biopsy and lumbar puncture have no specific contraindications in pregnancy. Endoscopic procedures, including bronchoscopy and upper and lower GI endoscopy, may both also be undertaken if necessary. However procedures requiring sedation and/or anaesthetic agents will need to take into account potential drug interactions with cART and possible foetal toxicity.

There are detailed guidelines relating to the use of X-rays and other imaging techniques in pregnant women.

When choosing imaging modality for the diagnosis of opportunistic infections in pregnant women consideration should be given to the need for a rapid diagnosis and the potential harm of the investigation. Discussion between HIV specialists, obstetricians and a senior radiologist is recommended.

Chest imaging : If an opportunistic infection in the lung is suspected a chest X-ray may be carried out with little or no risk to the foetus as long as an abdominal shield is used and due consideration is given to exposure times and position of the X-ray. Pulmonary embolus (PE) is a leading cause of maternal morbidity and death and suspected PEs need to be investigated and treated promptly Ventilation and perfusion (VQ) scans, or in some situations limited ‘perfusion’ scans, are regarded as acceptable with suspected PE in pregnancy. CT pulmonary angiogram (CTPA) scans are also being used more and are becoming regarded by many as the investigation of choice for the diagnosis of PEs in pregnancy. 

Abdominal imaging: Plain abdominal X-rays should generally be avoided. An ultrasound scan is a safe option for imaging of the abdomen. A direct CT scan of the foetus in the pregnant abdomen is contraindicated and, where possible, should be avoided. MRI scanning of the foetus and abdomen may be considered, although it is recommended to avoid them in the first trimester unless absolutely necessary.

CT/MRI imaging: CT scans of the brain, thorax or limbs of the mother maybe carried out with minimal exposure to the foetus. Modern CT scanners have little radiation scatter to areas outside the scanner itself, so the main radiation scatter affecting the foetus during a thoracic CT scan would be internally within the body of the mother. The use of contrast with CTscanning is permitted. However, Gadolinium, which is used in MRI scanning, is not recommended as it has been found to be teratogenic in some animal studies, and should be avoided if possible.