Introduction: Up to 50% of the infants delivered after radical vaginal trachelectomy (RVT) are born prematurely. An effective strategy to reduce this number could be the closure of the cervical os (CCO). Patients and methods: Fifteen pregnant patients who had a RVT due to early cervical cancer were included in this prospective case control study. All patients were scheduled for CCO early in the second trimester. CCO was performed in 12 patients. Their data were compared to data from 125 pregnancies after a RVT without CCO. Results: The patients who had CCO were compared to patients without CCO. One patient had an early rupture of the amniotic membranes prior to CCO. Two patients chose not to undergo CCO. In 12 patients CCO was performed without complications. There was no early preterm delivery in the CCO group as compared to a rate of 5% in 125 pregnancies in the non-CCO group. Discussion: We developed a protocol to reduce the risk of preterm deliveries after a RVT. Digital examinations should be avoided. Vaginal checks for pH can discover ascending infections – the main cause of preterm deliveries after a RVT. Infections should be treated adequately. CCO can further reduce the risk of preterm deliveries after a RVT.