Pregnancy After Concussion: A Clarion Call for Attention?

Objective: Emerging research shows that women who sustain a mild traumatic brain injury, also termed concussion, have a higher risk of menstrual irregularities and sexual dysfunctions. However, no research exists on how these reproductive disruptions affect women's subsequent pregnancies. The objective of this study was to evaluate pregnancy outcomes after concussion in a cohort of reproductive-aged women (aged 18-45 years), 24 months post-injury. We hypothesized that, compared with their extremity-injured peers in the same cohort, women with concussion will have lower incidence of pregnancies.

Setting: Emergency department of a level 1 trauma center.

Participants: Women of reproductive age (aged 18-45 years) seeking care for concussion or extremity injury.

Design: Longitudinal cohort study that used data collected at 3 distinct time points: t0, baseline: an original cohort of 245 women recruited in January to July 2017 for exposure assessment; t1, 6(+4) weeks post-injury: evaluation of self-reported postinjury menstrual and sexual changes for subgroup analyses-data collected in March to September 2017 ( n = 135); t2, 24 months post-injury: March 2020 chart review for documentation of pregnancies/pregnancy-related events ( N = 245).

Main Measure: Poisson regression estimates used to model the incidence rate (IR) of pregnancies, comparing concussion with extremity injury.

Results: We reviewed the charts of 254 women from the t0 cohort. After excluding 9 patients who were either deceased or missing relevant data, we had the 245 (96.5%) charts of 102 concussed and 143 extremity-injured study participants. After adjusting for race and obstetric history, women with concussion had 80% lower incidence of pregnancies than their extremity-injured peers (adjusted [adj] IR = 0.20; 95% CI: 0.07-0.59; P = .003). When we excluded women who were using birth control, the IR of pregnancy for women with concussions was 76% lower than for those who had sustained extremity injuries (adj IR = 0.24; 95% CI: 0.07-0.81; P = .02). Pregnancy incidence remained consistently lower for concussed women in additional sensitivity analyses excluding assault/domestic violence victims and those with a prior/new concussion at t0 and t2. Subgroup analyses of the 135 women who had experienced menstrual and/or sexual dysfunctions at t1 showed 84% reduced incidence of pregnancy for women with concussions compared with those who had sustained an extremity injury (adj IR = 0.16; 95% CI: 0.04-0.73; P = .02).

Conclusion And Relevance: Our study potentially serves as a clarion call to understand the long-term reproductive effects of female concussions.