Travelling does not lead to miscarriage but it causes excess nausea, vomits and exertion may induce bleeding, hence during first trimester when nausea, vomits are already there, there are chances of increased symptoms hence avoid travel in thst period
Next Steps
preferably travel in second trimester so that the nausea, vomits are already over by then, and you can enjoy the travel too
Health Tips
Always consult your gynecologist before travel, as there may be other reasons too to avoid than just the trimester, like low lying placenta or incompetent os or others