Prolonged Labour Clinical Trial
Official title:
Can Ultrasound Predict Labor Outcome in Operative Vaginal Deliveries?
To assess whether ultrasound methods can predict outcome of operative vaginal deliveries in
nulliparous women at term with singleton pregnancies and prolonged second stage of labor.
To compare different ultrasound assessments Compare digital assessments and ultrasound
findings. Investigate if movement of the fetal head during active pushing is a predictive
factor
Null hypotheses:
- Ultrasound measurements cannot predict outcomes of operative vaginal delivery.
- Ultrasound is not better than digital examination in predicting delivery outcome.
- Movement of fetal head with active pushing is not a predictive factor.
The physician responsible for the labor will perform digital examinations (fetal station and
position and cervical dilatation). Fetal station will be related to the ischial spine from
-5 to +4 as described by WHO and illustrated in Figure 111. Another obstetrician or midwife
blinded to the results from the clinical examination will perform the ultrasound
measurements. The physician responsible for the labor will be blinded to the ultrasound
measurements.
Ultrasound examinations between contractions
Due to considerations described below, only one recording/acquisition will be performed of
each of the following:
A) Head position B) Head-perineum distance C) Midline angle D) Angle of progression E) 3D
sagittal transperineal acquisition In addition single scans are performed during active
pushing as described under B) and D) (and a 3D sagittal scan when possible).
A) Head position Position will be assessed in 2D with a transabdominal scan as described by
Akmal4 and 3D in a transperineal scan as described by Ghi et al22. Fetal head position will
be recorded as a clock dividing the circle in 24 divisions
Positions ≥02.30 and ≤03.30 hours should be recorded as left occiput transverse and
positions ≥08.30 and ≤09.30 as right occiput transverse. Positions >03.30 and <08.30 should
be recorded as occiput posterior and positions >09.30 and <02.30 as occiput anterior.
Head-perineum distance will be assessed with transperineal ultrasound. The women will be
examined lying flat (or almost flat) in bed with flexed hips and knees position. The bladder
should be emptied immediately before the ultrasound examination.
Head-perineum distance will be measured as the shortest distance between the outer bony
limit of the fetal skull and the perineum with a transabdominal transducer placed
transperineally between the labia in a transverse view (posterior fourchette - posterior
commissure of the labia minor)
Midline angle will be measured as described by Ghi22. In a transverse transperineal scan the
angle between the midline of the fetal head and a sagittal line through the maternal pelvis
will be measured. This recording will also be performed in a transverse scan.
Angle of progression will be measured as described by Barbera and Kalache as the angle
between the long axis of the symphysis pubis and the tangent of the skull in a transperineal
sagittal scan.
The following outcome variables will be recorded upon delivery Main outcome
- Time from start of vacuum assisted traction to delivery (the entire body is delivered)
Secondary outcomes
- Number of contraction before delivery
- Number of cup detachments
- Successful/failed vaginal operative delivery
- Forceps applied/not applied
- Perineal tears
- APGAR score of newborn.
- Arterial umbilical cord blood pH and BD (base deficit) values.
- Position at delivery
Statistics:
The time interval between start of operative vaginal delivery and delivery will be evaluated
for the fetal head-perineum distance and angle of progression using survival analyses
(Kaplan-Meier analyses and Cox regression analyses).
Categorical variables will be analyzed using Chi-square test and Fischer exact test, and
continuous variable will be analyzed using T-test or Mann-Whitney U-test.
The predictive values for a successful operative vaginal delivery will be evaluated using
receiver-operating characteristics (ROC) curves. The area under the curve (AUC, - 95% CI) is
considered to have discriminatory potential if the lower limit of the CI exceeded 0.5.
Ultrasound measurements, digital assessment of station and dilatation, induction of labor,
maternal age, gestational age and birth weight will be analyzed in logistic regression
analyses with vaginal delivery vs. cesarean section as dependent variable.
;
Observational Model: Cohort, Time Perspective: Prospective
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Not yet recruiting |
NCT02232035 -
Diazepam at the Active Phase of Labor
|
Phase 2 |