Background: The diagnosis of threatened abortion is frequently made in clinical practice as a result of taking a history of vaginal spotting and the finding of a closed cervix at subsequent vaginal examination in first 20 weeks of gestation. Objective: This study was conducted to evaluate the incidence and relation between threatened miscarriage and preterm premature rupture of membranes (PROM) and also its effect on fetal growth. Patients and methods: The current study was conducted during a period of 8 months starting from 1st June 2019 till 31st August 2019. The patients were divided into two groups. First group: Included one hundred women presenting with threatened abortion at or below 20 weeks of gestation (case group). Second group: Included one hundred women who didn't have any symptoms of threatened abortion (control group). All patients were recruited from the Outpatient Clinics and Casualties of the Obstetrics and Gynecology Department, Al-Hussein and Bab Al-Sharia, Al-Azhar University Hospitals. Results: Our study showed that there were significant differences regarding abortion, preterm labor and intrauterine growth restriction in the case group compared to the control group. There was a relative increase in the incidence of premature rupture of membranes, hypertensive disorders, placenta previa and the rate of cesarean section in the case group compared to the control group. Conclusion: There was a relation between threatened abortion and adverse pregnancy outcomes.