Table 2.

Preterm delivery in patients with different central lengths and phosphorylated insulin-like growth factor binding protein-1 test results

Cervical length	Expression of phIGFBP-1	n	< 30 wk gestation	Between 30 and 34 wk gestation	Between 34 and 37 wk gestation	Preterm birth rate (%)
≤ 25 mm	Positive	63	20	13	12	45 (71.43)
	Negative	51	16	9	4	29 (56.86)
> 25 mm	Positive	60	0	1	3	13 (21.67)
	Negative	80	0	0	9	12 (15.00)

phIGFBP-1: Phosphorylated insulin-like growth factor binding protein-1.