Joint position statement from the Royal College of Radiologists and Royal College of Obstetricians and Gynaecologists
Risk avoidance in pregnancy has been found to lead to delays in diagnosis and treatment of cancers. The Maternal, Newborn and Infant (MNI) Clinical Outcome Review Programme Report1 published in 2021 highlighted concerns over the lack of imaging offered to pregnant patients for both diagnosis and staging of cancer.
This can be because of one of several reasons:
- Attributing new symptoms to pregnancy, by the patient or clinician
- Attributing new clinical signs or abnormal blood tests to pregnancy
- Reluctance of clinicians to refer pregnant patients for imaging
- Imagers' caution against undertaking investigations in pregnancy, particularly those involving ionising radiation.
There is often misunderstanding about the safety of imaging for pregnant and lactating patients resulting in unnecessary avoidance of useful diagnostic tests.
Clinicians who suspect cancer or other serious underlying disease in pregnancy based on the detailed history and clinical examination should default to standard pathways and make decisions based on risk/benefit rather than promote risk avoidance secondary to pregnancy. Pregnant patients should undergo relevant imaging whilst minimising exposure to ionising radiation.
The risks of ionising radiation to the foetus vary with gestational age and dose. Several articles have been published more recently detailing the benefits and risks associated with imaging in pregnancy, with recommendations on how to determine the appropriate techniques to use.2–4
Iodine-based intravenous contrast medium, as used in CT scanning, has transient effects on the pregnant patient, with potential for flushing, nausea and anaphylactoid reaction, as in all patients. This may cross the placenta and enter the amniotic fluid but has no teratogenic effects.2
To ensure the best care for pregnant patients across the UK, the Royal College of Obstetricians (RCOG) and Gynaecologists and the Royal College of Radiologists (RCR) are working to develop national guidance to help referrers determine the appropriate course of action. The use of iRefer (RCR Guidelines for appropriate imaging referrals) and early discussion between clinicians and radiologists is strongly advised.
- MBRRACE-UK. Maternal, Newborn and Infant (MNI) Clinical Outcome Review Programme. Saving Lives, Improving Mothers’ Care. Lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2017-19. November 2021.
- Eastwood KA, Mohan AR. Imaging in pregnancy. The Obstetrician & Gynaecologist 2019;21(4):255-262.
- Wiles R, Sharp A. Making decisions about radiological imaging in pregnancy. BMJ 2022;377.
- Chirag J. ACOG Committee Opinion No. 723: Guidelines for diagnostic imaging during pregnancy and lactation. Obstet Gynecol 2019:133(1):186.