Effects of flexible sacrum position at birth on maternal and neonatal outcomes: A retrospective cohort study

To examine the differences in both maternal and neonatal outcomes between flexible and non-flexible sacrum positions at birth.

A descriptive, cross-sectional, retrospective study was carried out on a sample of low-risk pregnant women. Univariate and multivariate logistic regressions and multivariate linear regressions were conducted to estimate the association between our discrete or continuous variables of interest. Maternal outcomes were perineal tear, maternal blood loss, second stage length; neonatal outcomes were Apgar scores and neonatal asphyxia. Results were adjusted for maternal age, neonatal birth weight, and epidural analgesia.

We considered for final analysis 2198 women. In primiparous women, women giving birth in the all-fours position were significantly more likely to have an intact perineum (P = 0.011) and a shorter length of the second stage of labor (P = 0.022). Maternal age (P = 0.005) and neonatal weight (P = 0.013) significantly increased perineal tearing; maternal age (P = 0.004) and neonatal birth weight (P < 0.001) were significantly associated with a higher amount of blood loss. Maternal age (P = 0.002) and neonatal weight (P < 0.001) significantly increased the length of the second stage of labor. For multiparous women, the side-lying position was significantly correlated with an intact perineum (P = 0.031); maternal age and intact perineum were statistically inversely associated. Epidural analgesia significantly increased the length of the second stage of labor in both nulliparous (P < 0.001) and pluriparous women (P < 0.001). No significant differences were found in neonatal outcomes.

Women with a low-risk labor should be free to choose their birth position as flexible sacrum positions are shown to increase maternal well-being and do not affect neonatal health.