Objectives: The aim of this study was to identify significant and modifiable risk factors associated with obstetric third and fourth degree perineal lacerations and to produce recommendations that may reduce their morbidity and prevalence.
Methods: This is a retrospective case control study performed between March 2004 and March 2008. All patients diagnosed with third and fourth degree perineal lacerations were identified (cases) along with randomly assigned controls who delivered during the same time period. Nineteen cases and 38 controls were identified giving a total of 57 patients. Each patient’s hospital record was collected and the data extracted.
Results: When analysed for weight greater than or equal to 3.5 kg versus birthweight of less than 3.5 kg, the difference between cases and controls was found to be statistically significant, with a p-value of 0.012. Of the cases, 21% had an operative delivery (forceps or vacuum) whereas only 2.6% of the controls had an operative delivery. This was found to be statistically significant (p = 0.011).
Conclusion: This study has shown that the two main factors related to the obstetric third and fourth degree perineal lacerations were babies weighing more than 3.5 kg and the use of forceps or vacuum to assist with deliveries. These high risk patients should be attended to by the most senior staff that is available.