Table 3:

Event rates for serious motor vehicle crashes during the baseline period and the second trimester of pregnancy, by crash characteristic

CharacteristicTotal no. of eventsEvent rate*Relative risk (95% CI)
BaselinePregnancy
Full cohort76794.556.471.42 (1.32–1.53)
Season
Spring or summer34642.052.931.43 (1.28–1.60)
Autumn or winter42152.503.541.42 (1.28–1.57)
Day of week
Weekday58073.425.091.49 (1.37–1.62)
Weekend18721.121.381.22 (1.04–1.44)
Time of day
Morning18431.071.801.68 (1.46–1.94)
Afternoon40962.423.511.45 (1.31–1.61)
Night17401.051.151.09 (0.92–1.31)
Total vehicles
Multiple70934.196.181.48 (1.37–1.60)
Single5860.360.280.78 (0.56–1.12)
Driver’s vehicle
Car72764.306.241.45 (1.34–1.57)
Other4030.250.230.93 (0.64–1.40)
Ambulance arrival
Yes34972.063.061.48 (1.33–1.66)
No41822.493.411.37 (1.24–1.52)
Triage urgency§
Higher45472.624.781.82 (1.67–1.99)
Lower31321.931.690.88 (0.76–1.02)
Hospital admission
Yes2410.150.171.18 (0.77–1.89)
No74384.406.301.43 (1.33–1.54)
  • Note: CI = confidence interval.

  • * Calculated per 1000 individuals annually during corresponding interval. Baseline spans the 3-year period before conception; pregnancy spans 3 total months of the second trimester. One month was defined as 28 consecutive days in all analyses

  • Morning is 4 am to 11:59 am, afternoon is 12 pm to 7:59 pm, night is 8 pm to 3:59 am (8 h each).

  • Other includes truck or miscellaneous vehicle.

  • § Higher urgency denotes resuscitation, emergency, urgency; lower urgency includes all other triage levels.