The World Health Organization (WHO) defines preterm birth as the birth of an infant earlier than 37 weeks (259 days) of gestation. [1] The almost 15 million preterm births recorded globally in 2010 represented more than one in ten live births, [1] with approximately 25% of newborn deaths recorded annually attributed directly to prematurity and 30% to secondary infections. [2,3] In addition, ~90% of preterm births and 99% of preterm deaths occur in developing countries. [4] In many low-income countries, only 30% of infants born between 28 and 32 weeks survive and almost all infants born earlier than 28 weeks die during the first few days of life. In these settings, the majority of deaths occur where primary care is not available. [1-4] In Ethiopia, specifically, preterm births contribute directly to 28% of newborn deaths. [5-7] Preterm birth often leads to lifelong complications, including neurodevelopmental impairment and disabilities such as learning difficulties, hearing impairment and behavioural problems, chronic lung disease, retinopathy of prematurity and lower growth achievement. [6] Preterm birth also affects the infant's family, who may have to spend substantial time and financial resources to care for the newborn. Preterm birth therefore has considerable cost implications not only for families but also for a country's health services. [8] The cause of preterm birth is unknown in almost half the cases. [5,9] Some risk factors have been identified, for example sociodemographic factors, history of obstetric abnormalities, intrauterine infections, pregnancy-related irregularities, and genetic and environmental factors. [1,4,10-16] However, the complexity and overlap of risk factors are not well understood and their mechanisms are unknown in most cases. Low socioeconomic status has been identified as a contributing factor in preterm births. [12-17] This may be attributed to women from low-income settings often experiencing nutritional deficiencies, insufficient healthcare, a low level of education and a stressful life. [13] Studies also show that a previous preterm delivery substantially increases a woman's risk of a subsequent spontaneous preterm delivery. [11,14,15,18,19] Multiple pregnancies and stillbirth have also been identified as risk factors for preterm delivery. [17-19] The aetiology of preterm births is multifactorial and evidence suggests that the prevalence varies depending on geographical and demographic features. To reduce the burden of preterm births, effective maternal care, including specific and comprehensive obstetric care for preterm newborns, is required. [20] Despite it being known that maternal complications and social settings have a substantial role in the underlying risk of preterm delivery, the magnitude and risk factors of premature births are not clearly known in Ethiopia. Methods Study setting and design The study was conducted in the central zone of the Tigray Regional State, which is approximately 1 000 km from Addis Ababa, Ethiopia's capital, and 220 km from the regional cap...