Table 1.

Maternal and Obstetric Factors in Relation to the Occurrence and Progression of ROP^*

	ROP Occurrence (Any Stage)			Severe ROP (Stage 3)			Vision-Threatening ROP Requiring Treatment (Type 1)
Variables	Absent	Present	P Value	Absent	Present	P Value	Absent	Present	P Value
No. of mothers	125	50		148	27		156	19
Maternal age (y)	32.0 ± 4.0	31.7 ± 3.8	0.703	31.8 ± 4.0	32.2 ± 3.9	0.624	31.8 ± 3.9	32.8 ± 4.0	0.259
Nulliparity	54 (43.2)	27 (54.0)	0.196	68 (45.9)	13 (48.1)	0.833	74 (47.4)	7 (36.8)	0.382
Cause of preterm delivery			0.264			0.575			0.768
Preterm labor	60 (48.0)	28 (56.0)		72 (48.6)	16 (59.3)		77 (49.4)	11 (57.9)
PPROM	63 (50.4)	20 (40.0)		72 (48.6)	11 (40.7)		75 (48.1)	8 (42.1)
Preeclampsia	2 (1.6)	2 (4.0)		4 (2.7)	0 (0.0)		4 (2.6)	0 (0)
Cesarean delivery	66 (52.8)	24 (48.0)	0.566	78 (52.7)	12 (44.4)	0.430	82 (52.6)	8 (42.1)	0.389
Antenatal corticosteroids	118 (94.4)	46 (92.0)	0.512	140 (94.6)	24 (88.9)	0.379	148 (94.9)	16 (84.2)	0.102
Antenatal antibiotics	97 (77.6)	40 (80.0)	0.728	114 (77.0)	23 (85.2)	0.344	121 (77.6)	16 (84.2)	0.768
Use of tocolytics	107 (85.6)	37 (74.0)	0.069	123 (83.1)	21 (77.8)	0.505	131 (84.0)	13 (68.4)	0.112
Gestational age at sampling (weeks)	28.4 ± 2.2	27.1 ± 2.3	<0.001	28.4 ± 2.2	26.6 ± 2.3	0.001	28.3 ± 2.2	25.6 ± 1.9	<0.001
Histologic chorioamnionitis	88 (70.4)	40 (80.0)	0.196	105 (70.9)	23 (85.2)	0.125	111 (71.2)	17 (89.5)	0.089
Funisitis	43 (34.4)	13 (26.0)	0.282	48 (32.4)	8 (29.6)	0.774	50 (32.1)	6 (31.6)	0.967
Clinical chorioamnionitis	11 (8.8)	8 (16.0)	0.167	16 (10.8)	3 (11.1)	1.000	16 (10.3)	3 (15.8)	0.439

^*Significant findings (P < 0.05) are presented in bold.

Values are mean ± standard deviation or number (%). PPROM, preterm premature rupture of membranes.