Background and Aims The PIEB technique is a promising approach that demonstrates certain advantages over traditional techniques epidural analgesia. We compared the incidence of motor block (MB) in women who received PIEB or traditional techniques for maintenance of labor analgesia.

Methods We studied 145 subjects. Term women with spontaneous labor and cervical dilation > 1–2cm were eligible to participate in the study. All parturients divided into 5 groups:

1. manual boluses (levobupivacaine 0.25%–10.0 ml);

2. PCEA (levobupivacaine 0.125% – 10.0 ml every 30’);

3. CEI (0.125% – 10.0 ml/hour) + PCEA (levobupivacaine 0.125% – 10.0 ml every 30’);

4. CEI (0.0625% – 15 ml/hour) + PCEA (0.0625% – 10.0 ml every 20’);

5. PIEB (0.0625% – 9.0 ml every 45 ‘) + PCEA (0.0625% – 10.0 ml every 10’).

The level of the motor block evaluated by the classic Bromage scale (0-1-2-3).

Results MB was reported in 80% in the 1 group by the 120th minute after analgesia, 78% and 52% in the 2 and 3 groups by the by 150 ‘ (p < 0.001); In group 4, the MB frequency is 6% after 15’ the start and was increasing to 40% at full cervical dilation (p < 0.001). In group 5, the relative MB frequency did not exceed 10% by 120’ and was 0% at full cervical dilation (p <0.00001).

Conclusions The PIEB technique showed the greatest effectiveness for labor pain relief with a minimum frequency of MB development.