Objective: To draw a comparison between spontaneous vaginal delivery and vacuum-assisted vaginal delivery in relation to the incidence and the type of levator ani avulsion in primiparas.
Design: Retrospective observational study. SETTIMG: Department of Obstetrics and Gynaecology, University Hospital of Ostrava.
Methodology: In the study, the primiparas who were from 6 to 12 months after spontaneous vaginal delivery (group A, n = 52) or after childbirth with vacuum extraction (group B, n = 51) underwent translabial 3D ultrasound. The obstetric data had been obtained from the hospital database. Translabial 3D ultrasound examination were performed by two sonographists. The monitored parameter was the distance between urethra and fibres of musculus levator ani - levator urethra gap [6]. The distance longer than 25 mm was considered an avulsion injury [6, 22]. Other parameters assessed in relation to the avulsion were: women's age, BMI, epidural analgesia, episiotomy performance, the length of the first and the second stages of labour, and fetal weight.
Results: Musculus levator ani avulsion was diagnosed in 10 women - unilateral in 8 cases and bilateral in 2 cases. In group A, women after spontaneous birth, we noticed avulsion injury in 7.7% of cases, whereas in group B, women after vacuum extraction, we recorded avulsion injury in 11.8% of cases. Thus the use of vacuum extraction is not statistically significant risk factor for avulsion musculus levator ani. Statistically significant difference in comparison group A and B was recorded in BMI, the length of the second stages of labour and episiotomy performance.
Conclusion: We did not prove a statistically significant connection between avulsion injury and delivery with the use of vacuum extraction in comparison to avulsion injury incidence in uncomplicated vaginal delivery group (tab. 1). Vacuum extraction does not appear as a risk factor for avulsion in contrast to forceps delivery.