Berlin survey on obstetric anal sphincter injury (OASI)

Abstract

Obstetric anal sphincter injuries (OASIs) complicate about 5% of vaginal births. The risk of anal incontinence is increased. OASI detection rates improve with knowledge and experience. This study describes Berlin's medical care 10years after starting training focusing on standards set at the German speaking country guideline on third degree tears. In 2018, women experiencing OASIs in Berlin's obstetric departments were informed about the study, including standardized after-care. Descriptive analysis in respect to anal sphincter function and risk factor analysis was performed. 207 OASIs occurred in Berlin. 189 women participated. In 148 cases guideline according terminology was applied (n = 57 IIIa, n = 58 IIIb, n = 23 IIIc, n = 10 IV). Minor tears predominated. Minor and major tears differed in respect to birthweight (p = 0.047). N = 75 reported no sphincter function affection. Macrosomia compromised sphincter function (p = 0.008). Univariate analysis showed age (p < 0.001), male infants (p = 0.017) and higher parity (p = 0.013) to be risk factors. Symptomatic women had weaker pelvic floor muscle (p = 0.009) and suffered from urinary incontinence (p < 0.001). Multiple regression analysis showed an association of St. Mark's Scores ≥ 5 with parity (CI 0.191-0.847, p = 0.016) and ≥ 10 with maternal age (CI 1.077-1.396, p = 0.002) and for urinary incontinence with birthweight (CI 1.000-1.002, p = 0.032 and St. Mark's categories ((0-4, 5-9, > 10) CI 2.657-10.904, p = 0.005)). Overall, Berlin's medical care of OASI is based on guideline standards. Anal and urinary incontinence correlate. Parity and higher age are risk factors in developing severe anal symptoms.