Levator Ani Deficiency and Pelvic Floor Dysfunction 1 Year Postpartum: A Prospective Nested Case-Control Study

Abstract

Objective: First, to assess whether levator ani deficiency (LAD) is associated with pelvic floor dysfunction 1 year postpartum, including urinary, vaginal and bowel symptoms; and second, to explore at what cut-off of LAD score such pelvic floor dysfunction arises.

Design: Nested case-control study.

Setting: Örebro University Hospital, Örebro, Sweden.

Population or sample: Primiparous women 1 year after vaginal birth.

Methods: Three-dimensional endovaginal ultrasound assessment of the levator ani muscle; LAD score based on this ultrasound, and validated questions about pelvic floor dysfunction. Logistic regression models were used.

Main outcome measures: Symptoms of pelvic floor dysfunction associated with LAD.

Results: Altogether 190 women were included, 103 of whom were symptomatic cases and 87 asymptomatic controls. 53% in the case group, and 58% in the control group had a LAD score of 0. A greater LAD score was significantly associated with urinary incontinence (adjusted odds ratio [aOR] 1.11, 95% confidence interval [CI] 1.00-1.22) and vaginal laxity (aOR 1.14, 95% CI 1.03-1.25). The risk of urinary incontinence was increased when the LAD cut-off score was set between ≥ 1 point and ≥ 4 points. The risk of vaginal laxity was increased when the cut-off was set between ≥ 8 and ≥ 14 points.

Conclusions: LAD was associated with both urinary incontinence and vaginal laxity. The risk of urinary incontinence increased already with minor LAD and defects of the most medial levator ani muscle portions normally supporting the midurethra may explain this increase.

Keywords: LAD score; levator ani avulsion; levator ani muscle; pelvic floor dysfunction; ultrasound; vaginal birth.