Pulling forces involved with forceps delivery and its association with maternal injury during birth

A prospective observational study of the traction forces required to deliver with forceps and it’s relationship to levator ani injury.

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN18126471

Enrollment

100

Registered

2019-08-22

Start date

2019-08-22

Completion date

Unknown

Last updated

2019-09-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Levator ani muscle avulsion during forceps delivery Pregnancy and Childbirth Levator ani muscle avulsion during forceps delivery

Interventions

This is a prospective study that will be carried out in a tertiary center where all the nulliparous women who undergo a forceps delivery during the study period will be included. The forceps that will

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: 1. Singleton pregnancy 2. Nulliparae 3. Forceps delivery (Pro-nata forceps)

Exclusion criteria

Exclusion criteria: 1. Twin deliveries 2. Breech deliveries 3. Previous vaginal delivery

Design outcomes

Primary

Measure	Time frame
Avulsion of the levator ani muscle. Avulsion will be diagnosed when a defect is observed at the puborectalis insertion using Tomographic Ultrasound Imaging (TUI) at the level of minimal hiatal dimensions and 2.5 and 5mm slices cranially. In doubtful cases, the ‘levator urethra gap’ will be used to rate individual slices as abnormal when the distance from the urethra to the insertion of the puborectalis muscle is more than 25mm.	—

Measure

Time frame

Avulsion of the levator ani muscle. Avulsion will be diagnosed when a defect is observed at the puborectalis insertion using Tomographic Ultrasound Imaging (TUI) at the level of minimal hiatal dimensions and 2.5 and 5mm slices cranially. In doubtful cases, the ‘levator urethra gap’ will be used to rate individual slices as abnormal when the distance from the urethra to the insertion of the puborectalis muscle is more than 25mm.

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Secondary

Measure	Time frame
Obstetric data gathered from patient records: 1. Date of the delivery 2. Age 3. Years from Menarche to delivery 4. Race 5. Weight at the beginning of pregnancy 6. Weight at the end of pregnancy 7. Height 8. Body mass index 9. Gestational age at birth: (completed weeks) 10. Epidural analgesia during dilation 11. Number of cesareans performed in the past 12. Induction of labor 13. Time of first stage of labor 14. Time of the passive expulsive period 15. Time of the active expulsive period 16. Anesthesia in expulsive period 17. Fetal position assumed when performing the instrumental delivery 18. Fetal head Asynclitism 19. Degree of fetal head flexion before applying the obstetrical instrument 20. Indication of instrumental delivery 21. Fetal station 22. Rotational forceps 23. Fetal position at birth 24. Failure of rotation attempt 25. Cesarean section after failure of forceps 26. Removal of the forceps before complete extraction of the fetal head 27. Number of pulls performed with the forceps 28. Maximum traction pull 29. Average traction pull 30. Area under the curve Traction/time 31. Episiotomy 32. Cervical tear 33. Vaginal tear 34. Perineal tear 35. Operator training 36. Operator sex 37. Number of forceps performed in the previous year 38. Number of operators that pull on the forceps 39. Subjective forceps difficulty 40. Fetal weight	—

Measure

Time frame

Obstetric data gathered from patient records: 1. Date of the delivery 2. Age 3. Years from Menarche to delivery 4. Race 5. Weight at the beginning of pregnancy 6. Weight at the end of pregnancy 7. Height 8. Body mass index 9. Gestational age at birth: (completed weeks) 10. Epidural analgesia during dilation 11. Number of cesareans performed in the past 12. Induction of labor 13. Time of first stage of labor 14. Time of the passive expulsive period 15. Time of the active expulsive period 16. Anesthesia in expulsive period 17. Fetal position assumed when performing the instrumental delivery 18. Fetal head Asynclitism 19. Degree of fetal head flexion before applying the obstetrical instrument 20. Indication of instrumental delivery 21. Fetal station 22. Rotational forceps 23. Fetal position at birth 24. Failure of rotation attempt 25. Cesarean section after failure of forceps 26. Removal of the forceps before complete extraction of the fetal head 27. Number of pulls performed with the forceps 28. Maximum traction pull 29. Average traction pull 30. Area under the curve Traction/time 31. Episiotomy 32. Cervical tear 33. Vaginal tear 34. Perineal tear 35. Operator training 36. Operator sex 37. Number of forceps performed in the previous year 38. Number of operators that pull on the forceps 39. Subjective forceps difficulty 40. Fetal weight

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Countries

Spain

Contacts

Public ContactIsmael Ortega

iortcar@gobiernodecanarias.org0034928444830

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026