Introduction IIH is a known metabolic neuro-ophthalmologic disorder which is associated with body weight gain. A common reason for increasing weight in child-bearing aged women is pregnancy. The long-term impact of IIH diagnosed during pregnancy is not known.

Aims and Methods Evaluate key outcomes such as visual acuity, visual fields, optical coherence tomog- raphy (OCT) and headache in a prospectively collected cohort within the IIH Life database (2013-2021). Comparison was made to those with a subsequent pregnancy, and those who never become pregnant.

Results People diagnosed with IIH in pregnancy had worse visual outcomes (Mean OCT Retinal Nerve fibre layer and PMD), as compared to the other two groups. None took intracranial pressure lowering medicines, few required temporising lumbar punctures and less required sight saving surgery. Overall, those who were not diagnosed in pregnancy had no sequalae, with the majority improving. All groups had comparable outcomes at 36 months.

Conclusions IIH patient monitoring during pregnancy is important, not only for maternal health but physician communication. Medical intervention is limited due to risk of teratogenicity. Those diagnosed with IIH in pregnancy, or those in whom IIH is exacerbated by pregnancy are more challenging to manage and require individualised care plans.