Intrapartum sonography head transverse and asynclitic diagnosis with and without epidural analgesia initiated early during the first stage of labor

Purpose: To investigate if early epidural analgesia can influence fetal head engage- ment into the pelvis and if it can increase the rate of transverse and asynclitic position during labour. Materials and Methods: 195 women with combined spinal-epidural analgesia (CSE) or with- out neuraxial analgesia were studied. CSE was performed using a mixture of ropivacaine 0.02% with 0.3 µg/ml of sufentanil administered in the spinal space. Maintenance of analgesia was man- aged with intermittent epidural administration of 10-15 ml of ropivacaine (0.07%-0.10%) mixed with 0.5 µg/ml of sufentanil, based on the stage of labour and the degree of pain. 2D transabdominal ultrasound (US) was used. Serial transabdominal US examinations were performed at 45-90 min in- tervals to detect transverse and asynclitic posi- tions, using the following signs: squint sign, sun- set thalamus and cerebellum signs that best de- tails the fetal head station. After delivery, the com- plete set of clinical and US data obtained by each examination were recorded and compared in women with and without labour analgesia. Data were examined by independent reviewers. Results: There was no difference in obstetric outcome between women in whom CSE had been used and those who did not request anal- gesia during labour (p>0.05). Conclusions: Epidural analgesia initiated early during labour and using low doses does not in- crease the rate of dystocic labors. Transverse fetal head positioning with anterior or posterior asyn- clitism does not seem to be promoted by drug or technique-related mechanisms, but rather should be the consequence of cephalopelvic disproportion.