The impact of pregnancy on headache evaluation in the emergency department, a retrospective cohort study.

BACKGROUND: Headache is one of the most common emergency department complaints with three million visits annually in the USA. This is further complicated with 30% of those emergency visits being for a hypertensive disorder of pregnancy. There is no currently well-established guideline for diagnostic imaging with a common concern being ionizing radiation exposure in pregnancy. The purpose of this study was to assess the difference in imaging studies ordered for pregnant and non-pregnant patients who reported to a tertiary care emergency department with headache.

OBJECTIVE: The purpose of this study was to assess the difference in imaging studies ordered for pregnant and non-pregnant patients who reported to a tertiary care emergency department with headache.

STUDY DESIGN: This retrospective cohort study identified all reproductive age female patients who presented to the emergency department with a chief complaint of "headache." They were then divided into cohorts based on pregnancy status. Rates and types of imaging studies utilized in patient evaluation were then compared.

RESULTS: Two thousand seven hundred ninety patients met our criteria for evaluation; 95 were found to be pregnant. Head CTs were ordered significantly less and MRIs were ordered significantly more in the pregnant cohort as compared to the non-pregnant cohort with a P value of <0.0001 and an odds ratio of 4.21 and a P value of 0.0127 and an odds ratio of 0.49, respectively.

CONCLUSION: Our data shows a difference in evaluation for pregnant patients as compared to their non-pregnant cohort. CT should not be considered contraindicated in the pregnant population and the amount of ionizing radiation to the fetus is well within the maximum safe dose, particularly with appropriate shielding. The time difference, cost, fetal exposure risk, and availability of CT compared to MRI should be taken into account when establishing a criterion for diagnostic evaluation. This difference validates the need for further research into a well-established guideline for the emergent evaluation of headache in the ED without special bias placed on pregnancy status.