Maternal posturing is used during labor to facilitate the rotation of occipitoposterior fetal position in anterior.

Our study aims to evaluate the efficacy of asymmetrical lateral decubitus for rotation of the fetal head.

The prevalence of fetal occipitoposterior position during labor is 20%. Compared to anterior positions, they are known to be at higher risk of complications (cesarean section, instrumental delivery, severe perineal laceration).

Maternal posturing is used during labor to facilitate the rotation of the fetal head in anterior position. Asymmetrical lateral decubitus is used frequently, without having ever been evaluated.

Our study aims to evaluate the efficacy of this maternal posturing, through a randomized open trial.

We hypothesized that posturing women in asymmetrical lateral decubitus allows increasing frequency of anterior fetal position after 1 hour.

Inclusion Criteria:

• women older than 18 years
• Gestational age ≥ 37SA,
• Ruptured membranes,
• single living fetus in cephalic presentation with an occipitoposterior position clinically diagnosed between 2 and 9 cm dilated and confirmed by ultrasound.
• Affiliation to a social security scheme (beneficiary or assignee)
• Signing the consent

Exclusion Criteria:

• Fetal presentation other than posterior
• Multiple pregnancy,
• Breech presentation
• History of previous cesarean section
• Fetal death in utero, termination of pregnancy
• Fetal intrauterine fetal growth restriction <5e percentile,
• Fetal malformation,
• Women younger than 18 years old,
• Women do not understand French,
• Women with psychiatric condition