Other factors considered in initial models but removed owing to P > .20 include nulliparity and maternal smoking during pregnancy. Battarbee et al. Optimal timing of antenatal corticosteroid administration. AJOG MFM 2020.

A 30-year-old nulliparous woman at 38 5/7 weeks of gestation developed a sudden, severe headache at work and subsequent loss of consciousness. She underwent evaluation in the emergency department. CT and CT angiogram head revealed a large intraparenchymal haematoma with intraventricular extension secondary to ruptured cerebral arteriovenous malformation (cAVM). She was intubated and transferred to a tertiary care centre. The patient underwent caesarean section followed by partial embolisation of the cAVM with planned second embolisation and resection 1 week later. Due to drowsiness and headache, the planned repeat embolisation and cAVM resection were performed 3 days earlier. The patient had a full recovery. Emergency medicine physicians and obstetrician-gynaecologists should be familiar with differential diagnosis of sudden headache in pregnancy and signs of a ruptured cAVM to facilitate early diagnosis, multidisciplinary team approach and timely treatment. Early diagnosis and management of ruptured cAVM are important due to associated morbidity and mortality.

Financial DisclosureStephanie Ros has been an UpToDate author on Zika virus in pregnancy. Tani Malhotra currently serves on the Board of Directors of the Accreditation Council for Graduate Medical Education (ACGME). They do not represent the Board and this article is not a reflection of the ACGME BOD. Brenna Hughes disclosed receiving payment from UpToDate and Merck. She received grants from NIH unrelated to this study paid to Duke. The other authors did not report any potential conflicts of interest.