Background: Pre-term birth is the main cause of neonatal mortality, morbidity and childhood disability and remains one of the most serious problems in obstetrics. PTB is defined as gestational age at birth of less than 37 completed gestational weeks. An estimated 15 million babies born too early every year, that is more than 1 in 10 babies (2). Approximately 1 million children die each year due to complications of pre-term birth many survivors face a life time of disability, including learning disabilities and visual and hearing problems. There are three-part series on preterm birth, which is the leading cause of perinatal morbidity and mortality in developed countries. Infants are born preterm at less than 37 weeks gestation after: spontaneous labor with intact membrane There are many factors that cause preterm labor These factors include demographic factors, obstetric history, cervical and uterine factors, bleeding, infection and other factors such as polyhydramnios or oligohydramnios, fetal anomalies especially involving multiple organ systems and central nervous system abnormalities, maternal abdominal surgery in late second or third trimester, maternal medical conditions such as diabetes mellitus and hypertension (essential or pregnancy induced) are associated with a higher rate of preterm delivery; however, these preterm birth are often intentional preterm deliveries because of maternal complications rather than the result of spontaneous preterm labor, the sign and symptoms of preterm labor include regular or frequent sensation of abdominal tightening, constant dull back pain, vaginal spotting and preterm rupture of membrane. Other maternal risk factors including multi gravity, short interval between pregnancies and history of abortion have an important role in the risk of pre-term labor. However, prevalence of these factors may vary among different communities.