Background
Pregnant women are more sensitive to respiratory pathogens due to adaptive anatomical and physiological changes in the respiratory system that occur during pregnancy, and these viral infections can cause pregnancy complications. Covid-19 was one of the viral infections that spread throughout the world for two years and left many side effects. The current study was conducted to determine the effect of COVID-19Pandemic on preterm birth in Isfahan.

Methods
Current study was a descriptive cross-sectional that was conducted in 1402. The study population included all pregnant women with preterm live birth in Isfahan between April 2018 and March 2021. Sampling was done by census and data was collected by checklist. The collected data were analyzed in SPSS version 16 .

Findings
The results showed that the percentage of change in the number of live births was 13.90%. The number of births during the COVID-19 pandemic was accompanied by a decrease of about 14% compared to the period before it. Also, the percentage of change in the number of preterm live births was 5.84%, which indicates that the number of preterm live births increased by about 6% during the COVID-19 pandemic compared to the previous period.