Table 1. Association between socio-demographic, reprodutive and pregnancy-related factors and preterm birth.

Characteristics	Full-term (n = 288)		Preterm (n = 288)		P value
	No.	%	No	%
Age, years
≤ 20	31	10.8	33	11.5
21–34	228	79.2	215	74.7	> 0.05
≥35	29	10.0	40	13.8
Weight, kg
≤45	108	37.5	113	39.2
46–54	145	50.3	121	42.0	< 0.05
≥55	35	12.2	54	18.8
Height, cm
≤ 145	15	5.2	15	5.2
146–154	132	45.8	131	45.5	> 0.05
≥155	141	49.0	142	49.3
BMI, %
≤ 18.5	69	24.0	65	22.6
18.6–24.9	212	73.6	201	69.8	< 0.05
≥25	7	2.4	22	7.6
Education, years
Primary (0–5)	46	16.0	69	24.0	< 0.05
High school (≥6)	242	84.0	219	76.0
Occupation
Farmer	68	23.6	89	30.9	< 0.05
Non-farmer	220	76.4	199	69.1
Parity
Nulliparous	152	52.8	163	56.6	> 0.05
Parous (≥2)	136	47.2	125	43.4
ANC visit (numbers)
0–3	81	28.1	118	41.0	< 0.001
≥ 4	207	71.9	170	59.0
Previous preterm births
No	282	97.9	249	86.5	< 0.001
Yes	6	2.1	39	13.5
Prenatal bleeding
No	286	99.3	255	88.5	< 0.001
Yes	2	0.7	33	11.5
Pre-eclampsia/Eclampsia
No	285	99.0	256	88.9	< 0.001
Yes	3	1.0	32	11.1
Secondhand smoking
No	141	49.0	94	32.6	< 0.001
Yes	147	51.0	194	67.4

ANC, Antenatal care