Perineal injuries and birth positions among 2992 women with a low risk pregnancy who opted for a homebirth

Background: Whether certain birth positions are associated with perineal injuries and severe perineal trauma (SPT) is still unclear. The objective of this study was to describe the prevalence of perineal injuries of different severity in a low-risk population of women who planned to give birth at home and to compare the prevalence of perineal injuries, SPT and episiotomy in different birth positions in four Nordic countries. Methods: A population-based prospective cohort study of planned home births in four Nordic countries. To assess medical outcomes a questionnaire completed after birth by the attending midwife was used. Descriptive statistics, bivariate analysis and logistic regression were used to analyze the data. Results: Two thousand nine hundred ninety-two women with planned home births, who birthed spontaneously at home or after transfer to hospital, between 2008 and 2013 were included. The prevalence of SPT was 0.7 % and the prevalence of episiotomy was 1.0 %. There were differences between the countries regarding all maternal characteristics. No association between flexible sacrum positions and sutured perineal injuries was found (OR 1.02; 95 % CI 0.86-1.21) or SPT (OR 0.68; CI 95 % 0.26-1.79). Flexible sacrum positions were associated with fewer episiotomies (OR 0.20; CI 95 % 0.10-0.54). Conclusion: A low prevalence of SPT and episiotomy was found among women opting for a home birth in four Nordic countries. Women used a variety of birth positions and a majority gave birth in flexible sacrum positions. No associations were found between flexible sacrum positions and SPT. Flexible sacrum positions were associated with fewer episiotomies.