Maternal and birth factors   P
Means %  
Maternal Age (years) <20years 37,929 ± 3,092 1,86 0,1503
20-34years 38,346 ± 1,931 73,61 0,2633
≥ 35years 38,261 ± 2,610 24,51 0,3523
Gestational Age  (Week) Preterm birth 32,615 ± 3,423 9,26 <0.0001
Term  deliveries 38,899 ± 0,459 90,74
Interpregnancy interval (years) Preterm birth 1,683 ± 1,854 9,26 0.0593
Term  deliveries 1,898 ± 1,804 90,74
Gestity Preterm birth 2,317 ± 1,674 9,26 0,0044
Term  deliveries 2,609 ± 1.627 90,74
Parity Preterm birth 1,176 ± 0,90 9,26 0.0028
Term  deliveries 1,459 ± 0,29 90,74
Etiology of preterm Anemia 36,750 ± 3,110 41.18 0.3978
Hypertension 37,986 ± 2,945 29.41 0.3034
Diabetes 38,400 ± 2,683 27.94 0.6725
PROM 37,374 ± 2,775 1.47 0.8589
Table 1: Maternal anthropometric and obstetric factors.