Thank you for your question.
Medical abortion is safer than surgical abortion when the gestation is less than 8 weeks. This is particularly true if no surgical intervention is required. Any surgery involves a risk of infection and damage to the uterus which can affect the ability to conceive subsequently. Other factors can include psychological effects and guilt which can affect subsequent attempts at conceiving. Theoretically, apart from these the chances of conceiving and carrying a pregnancy to term are not directly affected by having a single termination of pregnancy.
Hope this helps