A posterior baby, medically referred to as occiput posterior (OP) position, is a presentation where the baby is head-down but facing the pregnant person’s abdomen, rather than the back. This position is sometimes called “sunny-side up.” The most favorable position for birth is occiput anterior (OA), with the baby facing the spine. Many babies begin labor in the OP position and rotate spontaneously. Encouraging rotation, ideally before labor begins, aims to create optimal conditions for a smoother birthing process.
What a Posterior Baby Means for Labor
The posterior position can affect the length and intensity of labor because the baby’s head presents a slightly larger diameter to the pelvis, making descent and rotation more challenging. This position often leads to “back labor,” where the baby’s skull presses directly against the sacrum, causing intense lower back pain during contractions.
Labor with an OP baby may progress more slowly, resulting in a prolonged first stage and a longer pushing phase. If the baby remains posterior, there is an increased chance of needing interventions, such as vacuum, forceps delivery, or a cesarean section. Encouraging rotation increases the likelihood of the baby settling into the optimal anterior position, allowing a smaller head circumference to pass through the pelvis.
Self-Administered Positional Techniques
Positional techniques utilize gravity to encourage the baby’s back—the heaviest part—to swing toward the front of the abdomen, promoting rotation.
Hands-and-Knees and Posture
A primary strategy involves spending time in a hands-and-knees position, which uses gravity to pull the baby forward and create more space in the lower uterus. Maintaining this position for 20 to 30 minutes several times a day, particularly in the late third trimester, can be helpful.
Avoid positions that encourage the baby to rest against the spine, such as reclining deeply on a couch or leaning back in a chair. Instead, sit with knees lower than hips and the pelvis tilted slightly forward, achievable by sitting on a birth ball or backward on a dining chair. Pelvic tilts, performed while on hands and knees, involve gently rocking the pelvis back and forth to encourage movement.
Sleeping and Inversions
Sleeping on the side, especially the left side, with a pillow supporting the upper leg, can create a gentle “hammock” for the baby, encouraging favorable alignment. Inversions, which involve bringing the head lower than the hips, are an advanced technique that should be approached with caution and ideally after consulting a healthcare provider.
The goal of a forward-leaning inversion is to temporarily lift the baby slightly out of the pelvis, giving them space to rotate. These gravity-based practices are most effective when done consistently to create symmetry and space within the pelvis.
Seeking Professional Body Balancing Support
Professional modalities focus on releasing soft tissue tension and balancing the pelvis to create more room for the baby to rotate.
The Webster Technique
The Webster Technique, performed by certified prenatal chiropractors, is a specific adjustment aimed at restoring balance to the pregnant person’s pelvis. This technique addresses misalignment of the sacrum, which can cause tension in the attached uterine ligaments.
By reducing this tension, particularly in the round ligaments, the technique removes constraints on the uterus, allowing the baby greater freedom to move. This approach creates an environment where the baby can turn spontaneously, rather than physically turning the baby directly.
Other Bodywork
Specialized physical therapists or bodyworkers may also use techniques like side-lying releases. These focus on mobilizing the pelvic joints and releasing muscle tension to achieve similar balancing effects. These professional interventions are complementary to at-home positioning and are generally considered safe throughout pregnancy when performed by a practitioner trained in prenatal care.
Encouraging Rotation During Labor
Many posterior babies rotate to the anterior position during the active phase of labor due to the downward pressure of contractions. Continuous movement and specific labor positions are the primary strategies to facilitate this rotation once labor has begun.
Upright and forward-leaning positions are beneficial, as they harness gravity and increase the dimensions of the pelvic outlet. Standing while leaning forward onto a support, or assuming the hands-and-knees position during contractions, can help shift the baby’s back away from the spine.
Asymmetrical positions, such as lunging or placing one foot up on a chair, help open one side of the pelvis more than the other, encouraging rotation through the space created. If an epidural is used, movement is still possible using a peanut ball—an oblong exercise ball placed between the legs—to open the pelvis and encourage rotation while lying down. The knee-chest position, where the chest is low and the hips are elevated, is another technique shown to increase the spontaneous rotation rate of the OP fetus.