This report provides results from ninety primiparous women who were recruited from a university-based, tertiary care teaching hospital using enriched sampling techniques to maximize the probability of women in the study with some degree of any LA tear (Figure 1
The enriched sampling relied on inclusion criteria of “complex birth factors” heuristically suggestive of LA tear. Because the study began in 2004, we relied on our earlier pilot work [9 (link)] to select women who experienced what we refer to as a “complex vaginal birth.” That is, at least one of the following in their first vaginal delivery: 1) maternal age greater than 33 years, 2) second stage labor greater than 150 minutes, 3) infant weight greater than 4000 gm, 4) forceps, 5) vacuum, 6) third or fourth degree anal sphincter laceration. At the point of data analysis, additional studies in the field had been published so we considered other factors identified as potential complex birth events: episiotomy, larger infant head circumference, length of passive pushing time and use of epidural and oxytocin. Women were excluded from participating if age was less than 18 years, the primary healthcare language was not English, birth occurred before 36 weeks gestation, twin gestation, or an infant admitted to the neonatal intensive care unit.
The enriched sampling relied on inclusion criteria of “complex birth factors” heuristically suggestive of LA tear. Because the study began in 2004, we relied on our earlier pilot work [9 (link)] to select women who experienced what we refer to as a “complex vaginal birth.” That is, at least one of the following in their first vaginal delivery: 1) maternal age greater than 33 years, 2) second stage labor greater than 150 minutes, 3) infant weight greater than 4000 gm, 4) forceps, 5) vacuum, 6) third or fourth degree anal sphincter laceration. At the point of data analysis, additional studies in the field had been published so we considered other factors identified as potential complex birth events: episiotomy, larger infant head circumference, length of passive pushing time and use of epidural and oxytocin. Women were excluded from participating if age was less than 18 years, the primary healthcare language was not English, birth occurred before 36 weeks gestation, twin gestation, or an infant admitted to the neonatal intensive care unit.
