Risk factors for birth-related perineal trauma: a cross-sectional study in a birth centre.
OBJECTIVE
To identify maternal, newborn and obstetric factors associated with birth-related perineal trauma in one independent birth centre.


BACKGROUND
Risk factors for birth-related perineal trauma include episiotomy, maternal age, ethnicity, parity and interventions during labour including use of oxytocin, maternal position at time of birth and infant birth weight. Understanding more about these factors could support the management of vaginal birth to prevent spontaneous perineal trauma, in line with initiatives to reduce routine use of episiotomy.


METHODS
Cross-sectional study.


METHODS
Data were retrospectively collected from one independent birth centre in Brazil, during 2006-2009. The dependent variable (perineal trauma) was classified as: (1) intact perineum or first-degree laceration, (2) second-degree laceration and (3) episiotomy (right mediolateral or median).


RESULTS
There were 1079 births during the study period. Parity, use of oxytocin during labour, position at time of giving birth and infant birth weight were associated with second-degree lacerations and episiotomies. After adjusting for parity, oxytocin, maternal position at the expulsive stage of labour and infant birth weight influenced perineal outcomes among primiparae only.


CONCLUSIONS
Although the overall rate of episiotomies in this study was low compared with national data, it was observed that younger women were most vulnerable to this intervention. In this age group in particular, the use of oxytocin as well as semi-upright positions at the time of birth was associated with second-degree lacerations and episiotomies.


CONCLUSIONS
The use of upright alternative positions for birth and avoidance of use of oxytocin could reduce the risk of perineal trauma from lacerations and need to perform episiotomy.
National Council for Scientific and Technological Development (CNPq) Scholarship, University of São Paulo, São Paulo, SP, Brazil. floramaria@usp.br
Flora M B
FM
da Silva
Sonia M J V
SM
de Oliveira
Debra
D
Bick
Ruth H
RH
Osava
Esteban F
EF
Tuesta
Maria L G
ML
Riesco
D000293:Adolescent; D000328:Adult; D016550:Birthing Centers; D001938:Brazil; D003430:Cross-Sectional Studies; D004841:Episiotomy / Q000009:adverse effects / Q000145:classification; D005260:Female; D006801:Humans; D022125:Lacerations / Q000209:etiology*; D008485:Medical Audit; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology*; D060525:Pudendal Nerve / Q000293:injuries*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult