Third and Fourth Degree Perineal Tear in Four-Year Period at Sestre Milosrdnice University Hospital Center, Zagreb, Croatia.

OBJECTIVES

Obstetric anal sphincter injury (OASIS) includes the third and fourth degree of perineal injury. The risk for OASIS is about 1% of all vaginal deliveries. If not recognised and treated properly, obstetric anal sphincter injury can have serious consequences for reproductive age woman.

MATERIAL AND

METHODS

We have retrospectively gathered and analysed data on obstetric anal sphincter injury in a four-year period at our department. The control group in this study included vaginal deliveries in 2012.

RESULTS

We recorded 0.34% third and fourth degree of perineal injury in all vaginal deliveries, and 87.9% of those patients were primiparae. Episiotomy was performed in 57.6% of all women with obstetric anal sphincter injury. In 30.3% of cases, newborns were large for gestational age. Gestational diabetes was found in 9.1% of OASIS cases, occipitoposterior position was found in 9.1% of cases. Induced labour took place in 39.4%, and oxytocin infusion was applied in 60.6% of OASIS cases. Vacuum extraction was performed in 12.1% of deliveries with OASIS. The average BMI in 3a and 3b injuries was 29.9. In 3c degree it was 28.0, and in the fourth degree, it was 32.1. In 27.0% of OASIS cases due to the extent of the injury surgeon engagement was necessary. When compared with vaginal deliveries in 2012 we found a significant increase in OASIS in primiparas, large for gestational age, occipitoposterior position, induced labour, vacuum extraction and hypertension (P < 0.01). There is also increased incidence of OASIS in episiotomy and oxytocin use group (P < 0.05).

CONCLUSION

Low incidence of OASIS in our department is a result of active management of delivery, manual perineal protection and timely episiotomy.