Risks of having non-obstetric surgery during pregnancy

Project summary

Background

This study arose as a direct result of questions posed in the high risk obstetric anaesthetic clinic by patients who were scheduled to have cancer surgery whilst pregnant. Patients wanted to know the statistical risks of an adverse outcome to the pregnancy, including miscarriage, stillbirth, premature delivery or problems following birth such as admission to neonatal intensive care. Unfortunately, the current evidence base is not sufficient to answer these questions and therefore this constitutes a "knowledge gap".

Pregnant women undergo non-obstetric surgery in approximately 1-2% of pregnancies, common operations being appendicectomy, cancer surgery and orthopaedic procedures. In this situation, women and their doctors are understandably anxious about the risk of harm to the fetus. However, the current level of evidence is all between 20 and 40 years old and is therefore unlikely to be representative of current outcomes given the improvements in anaesthetic drugs, surgical techniques, and neonatal care. The previous studies are also, in general, poorly controlled and have conflicting results regarding the risk of surgery.

Nonetheless, of the evidence that is available, none relates directly to NHS outcomes, and there is no current NHS policy regarding carrying out non-obstetric surgery in pregnant women.

Aims

• To investigate the risk of adverse pregnancy outcomes (miscarriage, preterm labour, stillbirth, long birth weight, prolonged length of stay, maternal death and caesarian section) in pregnant women who have had non-obstetric surgery compared with those who didn’t have
• To estimate the risk associated with common procedure groups (such as appendicectomy, cholecystectomy, cancer surgeries, orthopaedic surgery and etc.).

Outputs

Peer-reviewed publications

• Balinskaite V, Bottle A, Sodhi V, Rivers A, Bennett PR, Brett SJ, Aylin P. The risk of adverse pregnancy outcomes following nonobstetric surgery during pregnancy: estimates from a retrospective cohort study of 6.5 million pregnancies. Annals of Surgery 2016; PubMed
• Aylin P, Bennett P, Bottle A, Brett S, Sodhi V, Rivers A, Balinskaite V. Estimating the risk of adverse birth outcomes in pregnant women undergoing non-obstetric surgery using routinely collected NHS data: an observational study. Health Services and Delivery Research 2016; 4 (29). PubMed
• Aylin P, Bennett P, Bottle A, Brett S, Sodhi V, Rivers A, Balinskaite V. The risk of adverse pregnancy outcomes following non-obstetric surgery during pregnancy: an observational study.  An International Journal of Obstetrics and Gynaecology 2016; 123 (2): 84. PubMed

Conference presentation

• Balinskaite V, Alex B, Brett S, Sodhi V, Rivers A, Aylin P. Non-obstetric surgery during pregnancy and adverse birth outcome. PHE Applied Epidemiology Scientific Meeting, March 2015.
• Balinskaite V, Bottle A, Sodhi V, Rivers A, Brett S, Bennett P, Aylin P. The risk of adverse pregnancy outcomes following non-obstetric surgery during pregnancy: an observational study. RCOG World Congress, June 2016

Reports

• Estimating the risk of adverse birth outcomes in pregnant women undergoing non-obstetric surgery using routinely collected NHS data: an observational study