The Effect of Birth Positions on Pelvic Floor Muscle Strength, Severity, and Quality of Perineal Pain in Primiparous Pregnant Women: A Randomized Controlled Trial

This study is a randomized controlled trial aimed at evaluating the effects of positions used during labor on pelvic floor muscle strength and the severity and nature of perineal pain in primiparous pregnant women. The World Health Organization (WHO) recommends supporting women's freedom of movement during the second stage of labor and encouraging upright birthing positions. However, in many countries, births are still performed in supine or lithotomy positions, and knowledge and practice regarding upright positions persist. This situation points to a significant knowledge and practice gap for both birthing women and healthcare professionals.

The study will be conducted at the Birth Unit of Bakırçay University Çiğli Training and Research Hospital, Izmir. Following ethics committee approval, the study will be conducted within one year. The sample will consist of 70 primiparous pregnant women who present to the birth unit and meet the inclusion criteria. Participants will be randomly assigned to the intervention and control groups via random.org. Pregnant women in the intervention group will deliver in the Semi-Fowler's (semi-sitting) position, while those in the control group will deliver in the lithotomy position, which is the hospital's standard practice.

Data will be collected in two stages. In the first stage, data will be collected at the onset of labor and when cervical dilation reaches 8-10 cm. In the second stage, data will be collected within 24 hours after delivery, at 6 weeks and 6 months postpartum. Data collection tools will be administered to each woman a total of five times in the first and second stages. Pelvic floor muscle strength will be assessed both objectively with a perineometer and subjectively with the Oxford scale. The severity and nature of perineal pain will be measured with the McGill Pain Scale Short Form.

The hypotheses of the study are that delivering in a semi-sitting position will increase pelvic floor muscle strength and reduce perineal pain. The data will be analyzed using the SPSS 23 software package, using parametric and non-parametric tests. Intention-to-treat (ITT) analysis will be applied when necessary to mitigate the impact of data loss.

This study aims to evaluate not only the effects of birthing positions on the labor process but also their impact on women's health in the postpartum period. This research, which will contribute to expanding the limited literature on this topic, is also expected to support the widespread adoption of a woman-centered approach to care in maternity services.