Comorbidity Patterns Among Pregnant Individuals With a History of Seeking Health Care for Migraine: A Population-Based Latent Class Analysis in Ontario, Canada.

BACKGROUND

Comorbidity is common with migraine. To inform services to support maternal well-being, we identified comorbidity patterns among pregnant individuals with a history of seeking health care for migraine before pregnancy.

METHODS

In a population-based cohort of pregnancies in 2007-2022 in Ontario, Canada, to individuals with migraine-related health care encounters in the 5 years before conception, we used latent class analysis to identify subgroups using 33 comorbidities. Classes were chosen using statistical fit indices, parsimony, and clinical interpretability. We compared the sociodemographic and reproductive health-related characteristics of the classes using standardized differences.

RESULTS

Of 174,164 pregnant individuals with migraine, 67.2% had one or more comorbidities. The most prevalent comorbidities were mood/anxiety disorders (41.4%), low back pain (16.9%), obesity (12.1%), and asthma (10.6%). Three distinct subgroups characterized comorbidity patterns: class 1, the "mood/anxiety disorder comorbidity," included 81.2% of the cohort; class 2, the "mood/anxiety disorder and low back pain comorbidity" cohort included 8.3%' and class 3, the "multiple mental health comorbidity" cohort included 10.6%. Compared with class 1, at conception individuals in the "multiple mental health comorbidity" group were more likely to be aged 13 to 24 years (37.9% vs. 18.9%; standardized difference, 0.43), reside in neighborhoods in the lowest income quintile (29.7% vs. 22.1%, 0.17), be Canadian born or a long-term resident (87.0% vs. 74.4%, 0.32), and be nulliparous (53.2% vs. 47.5%, 0.11). Those in the "mood/anxiety disorder and low back pain comorbidity" group were more likely to be 35 to 44 years of age (31.9% vs. 20.6%, 0.26) or 45 to 54 years of age (2.1% vs. 0.6%, 0.14), more likely to reside in neighborhoods in the lowest income quintile (26.6% vs. 22.1%, 0.11), and less likely to be nulliparous (38.6% vs. 47.5%, 0.18). Findings were similar in a sensitivity analysis including only comorbidities with a prevalence of 1% or greater. Using physical conditions as indicators only, we also identified three latent classes: "low back pain comorbidity" (4.3%), "obesity comorbidity" (2.8%), and "no physical comorbidity" (92.9%).

CONCLUSION

Comorbidity affects two-thirds of pregnant individuals with a history of seeking health care for migraine. Identified patterns of comorbidity suggest subgroups who may benefit from tailored perinatal support related to mental health and chronic pain.