Background: Inflammatory bowel disease (IBD) and pregnancy both impact health-related quality of life (HRQoL). However, little is known about IBD-related HRQoL around pregnancy.

Aims: To assess the trajectory and predictors of HRQoL in preconception and pregnant patients with Crohn's disease (CD) and ulcerative colitis (UC).

Methods: Preconception and pregnant patients with IBD were followed prospectively from preconception to twelve months postpartum at a tertiary referral centre. Participants completed the Short IBD Questionnaire (SIBDQ) and were assessed for clinical disease activity (modified Harvey Bradshaw Index or partial Mayo score) and objective disease activity (C-reactive protein [CRP], fecal calprotectin [FCP]).

Results: A total of 61 patients with IBD (25 CD, 36 UC) were included. During preconception, patients with UC had higher SIBDQ bowel and social sub-scores than those with CD, but this reversed during postpartum. Patients with CD but not UC developed a significant, sustained improvement in SIBDQ upon becoming pregnant, which persisted into 12 months postpartum. In a multivariable linear regression model, clinical disease activity negatively predicted SIBDQ at every pregnancy timepoint and up to 12 months postpartum. SIBDQ was significantly lower in patients with CRP ≥ 8.0 mg/L during trimester 1 (T1), but not later in pregnancy. SIBDQ bowel sub-scores were significantly lower in patients with FCP ≥ 250 mg/kg at T2, T3, and 6 months postpartum.

Conclusions: Clinical disease activity is a consistent negative predictor of HRQoL from conception to 12 months postpartum. Patients with UC experience better preconception HRQoL but suffer worse postpartum HRQoL than those with CD.