Determinants of vaginal-perineal integrity and pelvic floor functioning in childbirth.
OBJECTIVE
Our purpose was to evaluate risk factors for severe vaginal-perineal trauma and to ascertain determinants of pelvic floor strength.


METHODS
Secondary analysis of 459 nulliparous women enrolled in a randomized controlled trial of episiotomy was carried out. In a multivariate analysis we examined the association between (1) sulcus tears, (2) third- or fourth-degree tears, and (3) pelvic floor strength and selected demographic, physiologic, pregnancy-related, and intrapartum factors.


RESULTS
Unemployment and shorter second stage of labor were significant predictors of sulcus tears. Episiotomy, forceps use, and birth weight were important predictors of third- and fourth-degree tears. Whereas perineal intactness (use of episiotomy and spontaneous tears) was not influenced by exercise, a strong exercise profile was associated with fewer third- and fourth-degree tears in the presence of episiotomy. Exercise did not influence the rate of sulcus tears. A total of 35% of the variability in postpartum pelvic floor strength was explained by antepartum strength; however, we were only able to identify 5% of the factors contributing to antepartum pelvic floor strength.


CONCLUSIONS
Determinants of sulcus tears appear to be present before pregnancy; third- and fourth-degree tears are related to physician management. Exercise mitigates the potential for severe trauma induced by episiotomy.
Klein
M C
MC
Department of Family Medicine, McGill University, Montreal, Quebec, Canada.
Janssen
P A
PA
MacWilliam
L
L
Kaczorowski
J
J
Johnson
B
B
D000293:Adolescent; D000328:Adult; D004651:Employment; D004841:Episiotomy; D015444:Exercise; D005260:Female; D006801:Humans; D015994:Incidence; D007748:Labor Stage, Second; D007743:Labor, Obstetric; D015999:Multivariate Analysis; D017773:Pelvic Floor / Q000293:injuries / Q000502:physiology; D010502:Perineum / Q000293:injuries* / Q000502:physiology; D011247:Pregnancy; D012307:Risk Factors; D012421:Rupture / Q000453:epidemiology / Q000209:etiology; D014621:Vagina / Q000293:injuries*