Manual Versus Instrumental Rotation of the Fetal Head in Malposition at Birth (ROTATE Study): Protocol for a Randomized Controlled Trial.

backgroundApproximately 5% of women will be affected by fetal malposition at full cervical dilatation, with the occiput in transverse or posterior positions. These women are more likely to require assistance to give birth to their babies with either rotational vaginal birth or cesarean birth at full dilatation. Three different rotational methods can be used: rotational (Kielland) forceps, rotational vacuum, and manual rotation. Current evidence supporting the use of the 3 rotational methods is only from observational data. To date, no randomized controlled trial (RCT) of rotational methods has been completed.

objectiveThis study aimed to evaluate whether manual rotation of the fetal head in persistent malposition at full cervical dilatation reduces the risk of severe maternal perineal trauma without substantially increasing the risk of cesarean birth, compared with instrumental rotation.

methodsROTATE is a pragmatic, multicenter, 2-arm parallel group, open-label RCT of manual versus instrumental rotation of the fetal head in malposition at birth with an internal pilot and an embedded qualitative process evaluation. The primary outcome is to evaluate whether manual versus instrumental rotation at full cervical dilatation reduces the risk of severe perineal trauma (superiority outcome), defined as a third- or fourth-degree tear, without substantially increasing the risk of cesarean birth at full dilatation (noninferiority coprimary outcome). A sample size calculation found that 4988 participants are required to detect a clinically meaningful reduction of third- or fourth-degree tears from 6% to 4% with 90% power (α=.05). A total sample size of 5200 participants from approximately 40 sites is anticipated, as loss to follow-up is expected to be about 4%. Neonatal trauma, a composite of potential outcomes relating to intrapartum hypoxia and physical trauma, is a safety signal. The setting is National Health Service consultant-led maternity units across the United Kingdom. Randomization is performed after eligibility has been confirmed and verbal consent has been obtained. Randomization is undertaken via a 24-hour telephone service or web-based system. Participants are randomized at an individual level on a 1:1 ratio to manual or instrumental (forceps or vacuum) rotation. Written consent is sought postnatally.

resultsData collection took place between September 9, 2022, and November 5, 2024. The total number of recruits is 321. The data analysis of primary and secondary outcomes is ongoing at the time of submission.

conclusionsA multicenter RCT of rotational methods has been conducted in the United Kingdom. Although the trial was closed early due to challenges in meeting recruitment targets, the results are still highly anticipated.

trial registrationISRCTN ISRCTN10193017; https://www.isrctn.com/ISRCTN10193017. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/72505.