Birthing position and its influence on perineal trauma in primiparous women.

Abstract

Background: Perineal trauma during childbirth is a significant adverse maternal outcome, both acutely postnatally with pain and prolonged recovery time, and poor uro‐gynaecological outcomes including urinary incontinence. Birthing position has been identified as a determinate of perineal trauma risk, with suggestion of semi‐recumbent positioning being contributory. This paper aims to investigate birthing positions and their association with perineal trauma..

Methods: A retrospective study over 10 years of cephalic presentation vaginal births in primiparous women from a single centre in Victoria, Australia (n = 3,356) was conducted investigating the impact of birthing mode on perineal trauma. Logistic regression analysis was used to determine crude and adjusted odds ratio. Birthing positions were categorised into lying and upright and compared for rates of perineal tears. Additional exposures including maternal comorbidities and birth characteristics were also analysed.

Results: A total of 119 severe perineal tears were identified. The highest rates of perineal trauma were seen in birth stool (7.1%), lithotomy (6.1%) and squatting (8.3%) positions. Overall, the upright positions were marginally protective for tear development with odds ratio of 0.962. Lowest rates were seen in BMI >30 (2.5%), current smokers (0.7%) and hypertension (0%). Adjusted odds ratio for diabetes (10.5) and non‐smokers (4.002) were statistically significant for development of severe tears.

Conclusions: The rates of severe perineal trauma are equivocal in lying and upright birthing modes. Women should be supported in their choice of positioning during second stage. Emerging risk factors of BMI <30, non‐smokers and diabetics warrant further consideration in clinical guidelines.