# Motor Vehicle Driving During Pregnancy Does Not Influence Uterine Contractions

## TL;DR

This study found that driving a motor vehicle during pregnancy does not significantly affect uterine contractions or increase preterm birth risk.

## Contribution

The study is the first to empirically examine the relationship between driving and uterine contractions in pregnant women.

## Key findings

- No significant difference in vehicle velocity during uterine contractions versus no contractions.
- Low velocity was more common during contractions, but acceleration patterns remained unchanged.
- Driving appears safe and does not predispose to preterm birth.

## Abstract

No studies have effectively clarified the relationship between uterine contractions and the act of acceleration or driving behaviors in pregnant women.

To confirm the effect of driving a motor vehicle on physiological changes in pregnant women, we examined uterine contractions while driving.

Seventeen pregnant women with a gestational age of 30–35 weeks were enrolled in this study. Uterine contractions were monitored remotely using a mobile delivery monitoring device. Triaxial acceleration of the vehicle, vehicle velocity, and vehicle kinematics were monitored using a driving recorder.

The average number of uterine contractions per 30 min in all participants was 1.0 (range, 0.26–2.0). When comparing the median vehicle velocity during a uterine contraction with that when there were no contractions, no significant difference was found (23 km/hour vs. 31 km/hour, p = 0.36). The prevalence of low velocity (20 km/hour or less) was significantly higher, and that of higher velocity (50 km/hour or more) was lower during a uterine contraction than with no contractions (p = 0.023 and 0.012, respectively). When comparing resultant vehicle acceleration, no significant differences were found between women with uterine contractions and those with no contractions. The distributions were similar before and immediately before a uterine contraction and with no contractions.

Driving a motor vehicle should be considered a normal activity of daily life in pregnant women and seems unlikely to predispose to preterm birth.