Delivering a baby “sunny side up” refers to a specific fetal position during labor. Medically known as occiput posterior (OP), this position means the baby is head-down but faces the mother’s abdomen instead of her spine. While this orientation can introduce challenges, it is a common variation, and many babies are still delivered vaginally.
Understanding the Occiput Posterior Position
The occiput posterior (OP) position means the baby’s head is down, with the back of their skull (occiput) facing the mother’s back or spine. This orientation causes the baby to face the mother’s abdomen, visualized as “sunny side up” or looking upwards.
The ideal position for vaginal birth is occiput anterior (OA), with the baby’s head down and face towards the mother’s spine. While up to 34% of babies may be in an OP position at labor onset, most spontaneously rotate. Only 5% to 8% remain OP at delivery.
Factors Contributing to Occiput Posterior
Several factors can influence a baby’s position, contributing to the occiput posterior presentation. The mother’s pelvic shape, such as anthropoid and android types, can increase the likelihood of an OP position. Maternal posture and activity levels during pregnancy also influence fetal positioning.
Spending time reclining or slouching, instead of maintaining an upright posture, may contribute. An anterior placenta is another potential factor. Other contributors include nulliparity (first-time mothers), advanced maternal age, obesity, and longer gestational age.
Impact on Labor and Delivery
The occiput posterior position significantly influences labor and delivery. A common impact is prolonged labor, especially the second stage, as the baby’s head may not fit easily through the birth canal. The head’s largest diameter often presents, making descent and rotation challenging.
Mothers often experience intense lower back pain, or “back labor,” as the baby’s head presses against the sacrum. This position can also increase the need for medical interventions, like oxytocin augmentation. There is a higher chance of requiring assisted vaginal delivery with forceps or a vacuum device if the baby doesn’t rotate or descend adequately.
Persistent OP position may necessitate a cesarean section if labor fails to progress despite interventions. Increased pressure and prolonged pushing with an OP delivery can also lead to a higher risk of perineal tearing, including more severe third and fourth-degree lacerations.
Strategies for Management
Managing labor with an occiput posterior baby involves strategies to encourage rotation and facilitate vaginal delivery. Non-medical approaches focus on maternal positioning and movement. Remaining upright and mobile during labor can help open the pelvis and encourage rotation. Common positions include:
Hands-and-knees
Rocking
Lunges
Side-lying positions
Using a birthing ball
If the baby does not rotate spontaneously, medical interventions may be considered. A healthcare provider might perform a manual rotation, gently attempting to turn the baby’s head internally. Studies suggest manual rotation can increase spontaneous vaginal delivery rates.
If rotation is unsuccessful or labor stalls, assisted vaginal delivery with forceps or vacuum extraction may be used. A cesarean section is typically considered when the baby’s position prevents safe progress or poses significant risks, despite other interventions.