The presented study was aimed to assess factors associated with preterm birth to confront neonatal morbidity and mortality related with prematurity. After controlling for confounders, urban residency, ANC follow up, premature rupture of membranes, pregnancy induced hypertension and multiple pregnancy were factors significantly associated with preterm birth.
This study found that mothers who resided in urban areas had 60% reduced odds of developing preterm birth than those mothers’ resided in rural areas. This might be due to the fact that women living in urban areas have better access to the health care than in rural area which can play an important part in the prevention of preterm delivery.
Besides, women living in rural are more likely to be exposed to hard physical works and this increases the risk of preterm delivery particularly to women coupled with other risk factors for preterm delivery. Illiteracy which is more in rural area as opposed to urban area is also an important risk factor for preterm delivery. This finding is supported by other studies [12, 13].
The present study also revealed that mothers who had antenatal care follow up had 92% reduced odds of developing preterm birth than those mothers’ who had no antenatal care follow up. This might be due to the fact that having ANC can enhance health promotion, detect and prevent complications related with preterm delivery at earliest point. This finding is in line with studies done in central zone of Tigray , Debretabour  and Jimma .
According to the present study, mothers who had premature rupture of membranes had odds 3.78 times higher to experience preterm birth than their counterpart. This might be due to the fact that prolonged premature rupture of membranes will favor microorganisms to ascend to uterus causing intrauterine infection.
The microorganism will break down the fetal membranes and also produce phospholipase which leads to formation of prostaglandin and endotoxin, substances that stimulate uterine contractions and causing preterm labour. This finding is similar with studies done in Kenya , Nigeria , Iran , Debretabour  and Jimma .
The current study also verified that mothers who had pregnancy induced hypertension had odds 3.77 times higher to experience preterm birth than those who had pregnancy induced hypertension. This might be due to the fact that uteroplacental ischemia in the setting of pregnancy induced hypertension results in adverse pregnancy outcomes including preterm delivery and others. Besides, pregnancy induced hypertension is a frequent reason for terminating pregnancy at early gestation which results in preterm delivery. This finding is in line with studies carried out in Debretabour , Jimma , Kenya , Nigeria  and Iran .
The other factor associated with preterm birth is multiple pregnancies. Mothers who had multiple pregnancies had odds 5.53 times higher to develop preterm birth than their counterpart. This is due to the fact that multiple pregnancies cause distention of the myometrium leading to uterine contractions and cervical dilation.
Moreover, other obstetric complications like preeclampsia and polyhydramnios concomitantly occur with multiple pregnancies resulting in spontaneous or iatrogenic preterm birth. This finding is consistent with other studies carried out in Tanzania , Kenya , Central zone of Tigray , Jimma  and Debretabour .
Preterm babies are predisposed to serious illness or death during the neonatal period. Deprived of appropriate treatment, those who survive are at increased risk of lifelong disability and poor quality of life. Complications arising from preterm birth are the main cause of neonatal mortality and the second prominent cause of deaths among children under the age of 5 years .
According to the present study, 36.6% % of preterm neonates have died. The possible causes of death were a respiratory failure, apnea of prematurity, necrotizing enterocolitis and perinatal asphyxia. This finding is in line with study done in India in which perinatal mortality was 42.4% and respiratory distress, birth asphyxia and septicemia were common causes of death .
The finding of the present study is also consistent with study conducted in Jimma University specialized hospital in which prenatal asphyxia, sepsis, jaundice, low gestational age, respiratory distress syndrome and initial temperature were factors associated with premature infant death .
Limitations of the present study include; lack of information on body mass index, antenatal cortical steroids, monthly income and educational status due to retrieving data from secondary source. Larger sample have not been included in the present study due to lack of digitalization in handling of medical records of mothers in the study area (medical records of mothers were handled in a traditional way) and therefore to include larger sample, bigger funds and longer periods are needed. Consequently, smaller sample included in this study have resulted in low and/or absence of some of the chronic medical conditions.