Cumulative oxytocin dose in spontaneous labour - Adverse postpartum outcomes, childbirth experience, and breastfeeding.

OBJECTIVES: This study aimed to determine the association between the total cumulative oxytocin dose during labour and adverse postpartum outcomes, childbirth experience and breastfeeding in term primiparous women with spontaneous onset of labour. STUDY DESIGN: A prospective observational multicentre study, including 1395 women with spontaneous labour, in seven hospitals in Southeast Sweden. Multivariable logistic regression (Crude Odds Ratios (OR) and adjusted OR (aOR) for relevant confounders) was used to analyze the association between oxytocin dose and postpartum outcomes. The exposure was the cumulative oxytocin dose during labour, classified in percentiles (<25th, 25-75th, >75th). The outcomes were occurrence of obstetric anal sphincter injury, postpartum haemorrhage (blood loss > 1000 ml), Apgar score < 7 at five minutes, umbilical cord arterial pH, postpartum bladder overdistension, exclusive breastfeeding at one week and three months, and the woman's perceived birth experience. RESULTS: Women receiving high amounts (>75th percentile, >4370 mU) of oxytocin infusion during labour had an increased risk of postpartum haemorrhage (OR 2.73 (1.78-4.19)), an overdistended bladder (OR 2.19 (1.11-4.31)), an infant with an Apgar score < 7 at five minutes (OR 2.89 (1.27-6.57)), a negative birth experience (OR 1.83 (1.25-2.69)), and a decreased chance of exclusive breastfeeding at one week (OR 0.63 (0.41-0.96)). After adjusting for confounders, all outcomes remained statistically significant except risk of low Apgar score and chance of exclusive breastfeeding. CONCLUSION: In women with high cumulative oxytocin dose during labour prompt, and prophylactic administration of uterotonics after delivery of the placenta should be considered to reduce the risk of postpartum haemorrhage. The risk for bladder overdistension can be reduced by implementing routines for observation for signs of bladder filling in the early postpartum period, as well as routine use of bladder scans post micturition to assess for successful bladder emptying. As women's birth experience have a major impact on their future mental health, should be routinely assessed postpartum, and support should be offered to women with negative experiences.

Labor dystocia and oxytocin augmentation before or after six centimeters cervical dilatation, in nulliparous women with spontaneous labor, in relation to mode of birth.

BACKGROUND: The effects of diagnosing and treating labor dystocia with oxytocin infusion at different cervical dilatations have not been fully evaluated. Therefore, we aimed to examine whether cervical dilatation at diagnosis of dystocia and initiation of oxytocin infusion at different stages of cervical dilatation were associated with mode of birth, obstetric complications and women's birthing experience. METHODS: A retrospective cohort study, including 588 nulliparous term women with spontaneous onset of labor and dystocia requiring oxytocin augmentation. The study population was divided into three groups according to cervical dilatation at diagnosis of dystocia and initiation of oxytocin-infusion (≤ 5 cm, 6-10 cm, fully dilated) with mode of birth as the primary outcome. Secondary outcomes were obstetrical and neonatal complications and women´s experience of childbirth. Statistical comparison between groups using Chi-square and ANOVA was performed. The risk of operative birth (cesarean section and instrumental birth) was assessed using binary logistic regression with suitable adjustments (maternal age, body mass index and risk assessment on admission to the labor ward). RESULTS: The cesarean section rate differed between the groups (p < 0.001); 12% in the ≤ 5 cm group, 6% in the 6-10 cm group and 0% in the fully dilated group. There was no increased risk for operative birth in the ≤ 5 cm group compared to the 6-10 cm group, adjusted OR 1.28 95%CI (0.78-2.08). The fully dilated group had a decreased risk of operative birth (adjusted OR 0.48 95%CI (0.27-0.85). The rate of a negative birthing experience was high in all groups (28.5%, 19% and 18%) but was only increased among women in the ≤ 5 cm group compared with the 6-10 cm group, adjusted OR 1.76 95%CI (1.05-2.95). CONCLUSIONS: Although no difference in the risk of operative birth was found between the ≤ 5 cm and 6-10 cm cervical dilatation-groups, the cesarean section rate was highest in women with dystocia requiring oxytocin augmentation at ≤ 5 cm cervical dilatation. This might indicate that oxytocin augmentation before 6 cm cervical dilatation could be contra-productive in preventing cesarean sections. Further, the increased risk of negative birth experience in the ≤ 5 cm group should be kept in mind to improve labor care.