Vaginal birth can cause pelvic floor injuries, such as pubovisceral muscle (PVM) tear, a known risk factor for developing pelvic floor disorders such as pelvic organ prolapse. Women with PVM tear may be asymptomatic before the pelvic floor disorders develop. The prevalence of the PVM tear can reach 36% among postpartum women [1]. PVM tear evaluation is not a routine clinical practice. The objective of this study was to estimate the ability to identify PVM tear on the basis of a clinical exam using index finger palpatory assessment of the PVM. Women who need the palpatory assessment were shown in Figure 1.

Eighty-five women participated in this planned data study and had at least one risk factor for PVM tear during delivery (e.g., maternal age ≥ 33 years, second stage labor lasting ≥150 minutes, instrumented delivery, infant weight ≥ 4000 grams, and third or fourth degree anal sphincter laceration). Measures were obtained approximately 7 weeks after the first vaginal birth. A clinical visit included index finger palpatory assessment of the PVM bilaterally (palpating through the vaginal wall) to assess for PVM wholeness by an experienced nurse practitioner. If the body of the muscle is clearly felt, then coded as “present” on that side. If the body of the muscle completely torn away from its origin, then scored as PVM “absent.” If the examiner was unable to completely certain of the “present” or “absent” of the muscle, then scored “equivocal.” This process and scoring is then repeated on the opposite side. If both sides of PVM were present, without loss it was coded as 0. If one side PVM was palpable but another side was labeled as equivocal, it was coded as level 1. If both sides of PVM were labeled as equivocal, or one side was not palpable, it was coded as level 2. If both sides of PVM could not be palpated, it was coded as level 3. Magnetic resonance imaging (MRI) of the pelvis was done, as the gold standard measure of PVM status. PVM tears identified by MRI were initially categorized into 5 levels for each side: as no tear, subtle tear, less than 50% tear, greater than 50% tear, and complete tear for each side. Two sides of the tears were combined into four categories: no tear or subtle tear on both sides of PVM (coded as 0), < 50% unilateral tear (coded as level I), < 50% bilateral or ≥ 50% unilateral tear (coded as tear level II), and ≥ 50% bilateral tear (level III). Nurse practitioner and MRI radiologist were blind to each other’s findings. Data were analyzed using proportional odds modeling.

Nine percent of the women were identified with “absent” PVM on both right and left sides by palpatory assessment while 20% of the sample were identified with “present” PVM on both sides (Table 1). MRI results showed at least a partial PVM tear in 35% of the sample while the remainder had none or subtle tear on MRI (Table 1). The odds ratio (OR) of MRI-documented PVM tear identified by palpatory assessment of the PVM for structural wholeness was 3.62 (95% CI 1.70 – 7.73), p = .001.

The estimated odds of having a high level MRI-documented PVM tear category increased by 3.62 for each level increase in PVM loss status to palpatory assessment.

Index finger palpatory assessment at the site of the PVM can be used to estimate the odds of PVM tear in postpartum women with known PVM tear risk factors. With that information, an informed decision can be made for diagnostic tests, (for instance obtaining an MRI) and for decisions regarding clinical care. They may also be applicability to large research studies for estimating odds of a PVM tear across various populations, especially if combined with a reported history of obstetric risk factors for PVM tear, such as forceps delivery.

Dietz HP, Lanzarone V. Levator trauma after vaginal delivery. Obstet Gynecol, 2005; 106:707-711.