Context: Non-combat musculoskeletal conditions are endemic among service members and disproportionately affect females. Pregnancy and childbirth contribute to lower physical fitness assessment scores and higher body mass index, both risk factors for musculoskeletal conditions, for up to one-year post-pregnancy. However, there is a paucity of information regarding the impact of pregnancy on musculoskeletal conditions.
Objective: To explore the association between the post-pregnancy period and incident musculoskeletal conditions (MSK).
Design: Retrospective, longitudinal cohort study.
Setting: Medical and administrative data from the Medical Assessment and Readiness System.
Other participants: Female military service members with and without a pregnancy.
Main outcome measure(s): Months since pregnancy end, health history, and demographic and military service data were abstracted for each subject. Subsequent MSKs were identified with relevant ICD-10 codes. A multivariable logistic regression model assessed the association between the time since pregnancy end and MSK incidence.
Results: A total of 298,607 female service members were identified, of which 19,980 had a pregnancy. A larger percentage of post-pregnancy service members (65.8%) had a MSK diagnosis as compared to the non-pregnant cohort (60.3%). Adjusting for covariates, the model suggests a temporal influence on post-pregnancy MSK incidence, such that service members 3- to 4-months and 5- to 6-months post-pregnancy were more likely to be diagnosed with a MSK as compared to the non-pregnant cohort. However, service members <2 months post-pregnancy were less likely to be diagnosed with an MSK, and the odds of an MSK beyond 6-months decreased out to 24-months post-pregnancy.
Conclusions: Pregnancy may increase a service member's odds of sustaining an MSK 3- to 6- months post-pregnancy. Understanding the relationships between pregnancy and MSK risks may lead to changes in postpartum return-to-duty/activity policies, better enabling service members to care for themselves and their families.
Keywords: maternity leave; military; musculoskeletal injury; postpartum; rehabilitation.