Table 1.

Comparison of mean measures of the head induced stretch ratio and levator ani stretch ratio by delivery outcomes and severity of pelvic floor trauma

T-tests for Comparisons of Mean HISR and Mean LASR by Outcomes
	n	HISR Mean (std)	p	LASR Mean (std)	p
Length of Second Stage
≤ 90	137	2.39 (0.28)		7.88 (1.56)
>90	36	2.58 (0.27)	0.0003	8.85 (1.42)	0.0009
Mode of Delivery
Unassisted Vaginal	105	2.35 (0.25)		7.60 (1.37)
Assisted Vaginal	68	2.54 (0.30)	<0.0001	8.67 (1.71)	0.0001
Laceration
No Tear	13	2.26 (0.26)		6.90 (1.63)
Tear	160	2.44 (0.28)	0.03	8.17 (1.55)	0.007
Episiotomy
No	87	2.33 (0.24)		7.61 (1.36)
Yes	86	2.52 (0.30)	<0.0001	8.56 (1.65)	<0.0001
LAD Score
< 7	108	2.30 (.028)		7.98 (1.45)
≥ 7	26	2.40 (0.33)	0.11	8.75 (1.70)	0.03
LAD Score
< 14	128	2.40 (0.29)		8.05 (1.54)
≥ 14	6	2.62 (0.38)	0.08	9.89 (2.00)	0.005