Idiopathic intracranial hypertension: Evaluation of births and fertility through the Hospital Episode Statistics dataset

Objective: Idiopathic intracranial hypertension (IIH) predominantly affects women of reproductive age with obesity, and these women have a distinct profile of hyperandrogenism and insulin resistance. Polycystic ovary syndrome (PCOS) has an established adverse fertility phenotype that typically affects obese women. As IIH may impact reproductive health, we sought to evaluate fertility, gestational complications and pregnancy outcome in IIH. Design: Prospective cohort study from English Hospital Episode Statistics dataset. Setting: English hospitals, UK. Population: Women aged 18–45 years seen in English hospitals between 1 April 2002 and 31 March 2019. Patients were required to have an IIH diagnosis and were compared with those with PCOS and general population female controls. Main outcome measures: Pregnancies resulting in live births, complications of gestational diabetes and pre-eclampsia, and method of delivery. Results: Data was collected from 17 587 IIH, 199633 PCOS and 10 947 012 women in the general population. The live birth rate, adjusted for age, was significantly lower among women with IIH (54.1%) than PCOS (67.9%), p < 0.0001 and the general population (57.7%), p < 0.0001. Pre-eclampsia and gestational diabetes risks were higher following a diagnosis of IIH (5.3-fold and 2.7-fold, respectively, p < 0.0001) compared with the general population controls. Following a diagnosis of IIH, elective caesarean section rates were more than twice that of general population (odds ratio [OR] 2.4) and prior to a diagnosis of IIH (OR 2.2). Conclusions: These data indicate there are lower age-adjusted total pregnancy rates, increased risk of pre-eclampsia and gestational diabetes, and a doubling of elective caesarean section rates in those with a diagnosis of IIH.