Aim: This study aimed to explore midwives’ experiences and views of amniotomy and its prevalence and complications in Sweden.

Methods: Study I was a qualitative study in which 16 midwives participated in individual interviews. Data were analysed using content analysis. Studies II, III, and IV were quantitative, for which register data from the Swedish Pregnancy Register were used, covering 95% of all births in Sweden. Analyses were performed using descriptive and comparative statistics, as well as simple and multiple logistic regression.

Results: Midwives discourage a routine use of amniotomy and want a clear indication of when to perform it. The decision, whether an amniotomy would support or interfere with the physiological process of labour was sometimes difficult for the midwives. The decisions were customized to each woman, based on the midwife’s knowledge and experience, but also regulated, and affected by the working environment. The overall prevalence of amniotomy in Sweden was 40%, and variations between hospitals were observed. A decrease in the prevalence of amniotomy was seen for women belonging to Robson groups 1 and 3. Increasing rates of induced labours thus resulted in an unaltered overall prevalence. The severe complication of umbilical cord prolapse is rare in Sweden, affecting 0.13% of labours with amniotomy. Higher parity, a baby in non-cephalic presentation, induction of labour, previous caesarean section and the presence of polyhydramnios were identified as risk factors for umbilical cord prolapse for labours with amniotomy. Severe perineal trauma is more common for both nulliparous and multiparous women who undergo amniotomy, thus amniotomy was not identified as a significant risk factor when adjusting for other risk factors. Women with severe perineal trauma have a longer duration between the amniotomy and the birth, compared to women without severe perineal trauma, regardless of parity. A longer duration between the amniotomy and the birth of the baby thus decreased the odds for severe perineal trauma for nulliparous women with amniotomy.

Conclusion: This thesis provides evidence about amniotomy from different perspectives, including midwives and register data. The midwives’ experienced and viewed amniotomy as both a simple everyday task and as an intervention demanding respect. Midwives want a clear indication of when to perform amniotomy and express an unwillingness to have a routine use. Almost half of the women who give birth in Sweden undergo amniotomy, however, variations in the prevalence between hospitals were observed. The prevalence of amniotomy remained stable for all births during the years 2017-2020, but a decrease was seen for women with spontaneous onset of labour. Umbilical cord prolapse is a rare complication to amniotomy. Women with higher parity, previous caesarean section, polyhydramnios, a baby in a non-cephalic presentation and induced labours should be carefully evaluated in the decision-making of amniotomy. Amniotomy is frequently used in labours where other, confirmed risk factors for severe perineal trauma are present. Amniotomy is thus not a significantrisk factor for severe perineal trauma when adjusting for the risk factors inregression analysis.