(1289) The Impact of Anemia on Fetal Growth Trajectory in Patients with Inflammatory Bowel Disease

To investigate the effect of anemia on longitudinal fetal growth in patients with inflammatory bowel disease (IBD).

Study Design:

This retrospective cohort study included singleton pregnancies among patients with IBD who delivered at a single academic center from January 2019 to December 2023. Demographic and clinical data was collected. Anemia was defined as a hemoglobin less than 11g/dL at delivery. Estimated fetal weights (EFWs) by Hadlock criteria, obtained from all maternal-fetal medicine ultrasounds, were collected and plotted against gestational age in days. Fetal growth trajectories were modeled using a fourth root transformation and compared using mixed effects models to account for repeated ultrasound measurements within subjects. Clinical outcomes were compared using Kruskal-Wallis test or Chi-squared test.

Results:

Among 100 deliveries in 89 patients with IBD, 26% (n = 26) had anemia upon admission for delivery. Rates of IBD remission at conception (85.1% vs. 88.5%, p = 0.80) and disease flares in pregnancy (19.2% vs. 16.2%, p = 0.72) were similar between anemic and non-anemic patients. Neonatal birthweights (3436g ± 371 g vs. 3290g ± 570 g, p = 0.21) and rate of neonates born small for gestational age (3.8% vs. 9.5%, p = 0.36) did not differ by anemia status. Mean fetal weight gain in grams per day was similar (22.5 vs. 21.2, p = 0.15) (Table 1). Mixed effects modeling revealed no significant difference in fetal growth trajectory by anemia status (p = 0.230) (Figure 1).  

Conclusion:

Maternal anemia was not associated with altered fetal growth trajectory in pregnancies complicated by IBD.