An observational study in Obstetric Anesthesia Problems, sponsored by Guy's and St Thomas' NHS Foundation Trust. Completed at 1 site in United Kingdom. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-09.
Sponsored by Guy's and St Thomas' NHS Foundation Trust · Observational
Our aim is to investigate whether a novel landmark, the groove between the buttocks or the intergluteal cleft, can facilitate the identification of the neuraxial midline in obstetric patients when compared to ultrasound as the reference standard for the determination of this midline
Determine if the intergluteal cleft, when compared to ultrasound as the reference standard, can be used to identify the neuraxial midline in obstetric patients
Difference in horizontal distance between the vertical lines of the intergluteal cleft and the neuraxial midline, the latter measured with ultrasound
Guy's and St Thomas' NHS Foundation Trust is the lead sponsor of 284 studies on the registry; 79 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Pregnant patients
Exclusion criteria
Each patient will be requested to adopt a standardised upright position. First, two of the investigators will use a spirit level ruler and ink pen to agree upon and visibly mark the horizontal intercristal line on the back of the patient. Second, investigator B will leave the room, and investigator A will make a vertical mark with an ultraviolet pen denoting the intersection of the inferior aspect of the intergluteal cleft and the horizontal intercristal line. Third, investigator A will then leave the room, and investigator B will return to the room to make a vertical mark with an ink pen representing the intersection of the neuraxial midline, as established with the transverse spinous process view on ultrasound, and the horizontal intercristal line. After these two vertical marks have been made at the level of the intercristal line, the horizontal distance between them will be measured in mm by these same two investigators
Diagnostic Test: Intergluteal Cleft · Diagnostic Test: Neuraxial Midline · Diagnostic Test: Horizontal Distance between Vertical Markings
Marking of intersection between inferior aspect of the intergluteal cleft and the horizontal intercristal line
Marking of intersection between the neuraxial midline, as established with the transverse spinous process view on ultrasound, and the horizontal intercristal line
The horizontal distance between these two vertical marks will be measured at the level of the intercristal line
Horizontal distance between intergluteal cleft and neuraxial midline
One horizontal distance and hence one primary outcome
Time frame: 12 months
Difference in horizontal distance stratified by body mass index
Variation for BMI and recorded data
Time frame: 12 months
Difference in horizontal distance stratified by presence of pre-eclampsia
Variation for pre-ecalmpsia and recorded data
Time frame: 12 months
Difference in horizontal distance stratified by presence of pregnancy induced hypertension
Variation for pregnancy induced hypertension a and recorded data
Time frame: 12 months
Plan to share: No
No publications or documents are linked to this record.
This study is completed, as verified in Feb 2024. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Guy's and St Thomas' NHS Foundation Trust