Labor, Obstetric
Conditions
Brief summary
The use of ultrasound has been suggested to support the management of labour. According to several studies, ultrasound examination is more accurate and reproducible than clinical examination in diagnosing fetal head position, fetal station, and the prediction of labour arrest. Furthermore, there is growing evidence that ultrasound in labour may predict the outcome of instrumental vaginal delivery: a support to assess when an operative delivery is necessary. Ultrasound in labour can be performed using a transabdominal approach, mainly to determine head and spine position, or a transperineal approach, to assess head station and the situation at low stations. Several sonographic parameters have been proposed to evaluate the head station. Furthermore, all ultrasound parameters studied so far, have always been measured with the woman in a supine position. While the biomechanics of childbirth with its mechanisms (known as nutation, counter-nutation of the pelvis, and the coccyx retropulsion) together with maternal movement, promote fetal rotation and the adaptation of its diameters with those of the maternal pelvis, allowing to gain more room for the fetal descent. Moreover, in most of the studies on intrapartum ultrasound, the mobility of the pelvis has not been mentioned. The contracted pelvis is the absence of mobility that leads to fetal-pelvic disproportion, arrest of labour, and operative delivery. Maternal pelvis biomechanics studies by high technological techniques have shown that maternal shifting positions during pregnancy and childbirth can create more room in the pelvis for safe delivery. The external and internal pelvic diameters are closely related. For this reason, the evaluation of the mobility of the pelvis appears to be a necessary element to understand the ability of that pelvis to widen its diameters for fetal descent. The aim of the study is to measure the variation of AoP, HPD in the supine position and in kneeling-squat position in the same woman and the cut-offs of the new ultrasound parameters and predictive capacity for vaginal birth.
Interventions
OTHERTransperineal imaging
To measure the difference between ultrasound parameters based on maternal position: to measure the variation of Angle of progression (AoP), ), HPD(head perineum distance) expressed in millimeters, in the supine position and kneeling squat position in the same woman during the expulsion phase, in the resting step and during the push.
Sponsors
University of Padova
Azienda Ospedaliera di Padova
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SCREENING
Masking
NONE
Intervention model description
Prospective, multicenter, single-group interventional study with randomized intra-subject comparison of assessment positions.
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* pregnant women with singleton pregnancies * at term gestation (37 weeks) * fetus in cephalic presentation * absence of factors hindering vaginal delivery
Exclusion criteria
* complicated pregnancies * vaginal birth after Cesarean * twin pregnancies * early pregnancy * women condition that exclude vaginal birth
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ultrasound AoP EP | Beginning of the expulsive phase (active second stage): with complete dilation and the perception of an urge to push. | To measure AoP (Angle of progression), expressed in degrees in the supine position and kneeling squat position in the same woman during the expulsion phase (EP) up to 3 hours |
| Ultrasound AoP RS | During the resting step | To measure AoP (Angle of progression), expressed in degrees in the supine position and kneeling squat position in the same woman during the resting step (RS) up to 3 hours |
| Ultrasound AoP P | During the push | To measure AoP (Angle of progression), expressed in degrees in the supine position and kneeling squat position in the same woman during the push (P) up to 3 hours |
| Ultrasound HPD EP | Beginning of the expulsive phase (active second stage): with complete dilation and the perception of an urge to push. | To measure the HPD (head perineum distance) expressed in millimeters, in the supine position and kneeling squat position in the same woman during the expulsion phase up to 3 hours |
| Ultrasound HPD RS | During the resting step | To measure the HPD (head perineum distance) expressed in millimeters, in the supine position and kneeling squat position in the same woman during the resting step up to 3 hours |
| Ultrasound HPD P | During the push | To measure the HPD (head perineum distance) expressed in millimeters, in the supine position and kneeling squat position in the same woman during the push up to 3 hours |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| mode of delivery | during delivery | mode of delivery |
| duration of labour stages | during labour stages | duration of labour stages up to 18 hours |
| Midwifery interventions during labour | during labour (hours) | Midwifery interventions during labour |
| Variation in the anteroposterior diameter of the levator hiatus | during labour (hours) | Variation in the anteroposterior diameter of the levator hiatus |
| reasons for possible caesarean section | immediately after caesarean section | reasons for possible caesarean section |
| Apgar Index at 1 min after delivery | One minute after delivery | Apgar Index |
| Apgar Index 5 minutes after delivery | Five minutes after delivery | Apgar Index |
| pH | Within 1 hour after delivery | pH |
| BE | Within 1 hour after delivery | Bases excess |
Countries
Italy
Contacts
CONTACTAlessia Selmin
CONTACTHonoria Ocagli, PhD
Outcome results
None listed