Bearing down is the powerful, expulsive effort a person makes during the final phase of childbirth to push the baby through the birth canal. This action, often involuntary, marks the transition into the second stage of labor, following full cervical dilation. It combines the body’s natural reflex with voluntary muscular effort, enabling the final descent and emergence of the infant.
The Physiology of Bearing Down
The physical act of bearing down relies on multiple muscle groups working in concert to generate immense intra-abdominal pressure. This force begins with a deep inspiration, followed by the contraction of the diaphragm and the abdominal muscles. The diaphragm moves downward while the abdominal muscles contract inward, effectively squeezing the abdominal contents.
This coordinated action significantly raises the pressure inside the abdominal cavity, acting downward on the uterus. This adds an expulsive force to the involuntary uterine contractions. Simultaneously, the pelvic floor muscles must relax and stretch to allow the baby’s head to pass through the vaginal opening.
The involuntary urge to push is often triggered by the Ferguson Reflex, a neurohormonal feedback loop. As the baby’s head presses against the sensory nerve endings in the pelvic floor and cervix, a signal prompts a surge of oxytocin. This increased oxytocin release intensifies contractions and creates a powerful, often irresistible, reflex to bear down.
Recognizing the Second Stage Urge
The onset of the urge to bear down signals the shift from the first stage of labor (cervical dilation) to the second stage (active pushing and delivery). This sensation is distinctly different from earlier labor contractions, manifesting as a deep, primal pressure originating low in the pelvis.
Many people describe the feeling as a sudden, overwhelming need to have a large bowel movement. This intense rectal pressure occurs because the baby’s head compresses the nerves and structures surrounding the rectum. The urge typically builds with the peak of a contraction and recedes, allowing for rest.
The presence of this powerful, expulsive feeling indicates that the cervix has likely reached full dilation (10 centimeters). Following the body’s natural cues ensures that pushing efforts are most effective and coordinated with the peak strength of the uterine contractions.
Directed Versus Physiologic Pushing
Historically, care providers commonly employ directed pushing, often referred to as the Valsalva maneuver. This method involves the birthing person taking a deep breath, holding it, and pushing forcefully for a count of 10, typically repeated multiple times with each contraction.
While directed pushing may shorten active pushing time, it has physiological trade-offs. Holding the breath and straining reduces blood return to the heart, which can temporarily decrease oxygen flow to the placenta and baby. This strenuous effort can also lead to maternal exhaustion, increased risk of perineal tearing, and elevated blood pressure.
In contrast, physiologic pushing encourages the birthing person to follow their body’s innate urge to bear down. This approach uses an open glottis, allowing the person to exhale or make noise while pushing, preventing prolonged breath-holding. Pushing efforts are guided by the natural reflex rather than external instruction.
Evidence suggests that spontaneous pushing often results in better outcomes for both mother and baby, including lower rates of maternal fatigue and improved oxygenation. This technique allows the body to conserve energy and coordinates voluntary efforts with involuntary uterine forces more efficiently.
When to Wait Before Bearing Down
Traditional guidance recommends waiting until the cervix is completely dilated to 10 centimeters before beginning active, forceful pushing. This rule was established out of concern that pushing against a partially dilated cervix could cause swelling, laceration, or injury. If the urge occurs before this point, the person is often instructed to use short, panting breaths to resist the sensation.
A practice known as laboring down is often utilized, particularly when an epidural is in place and the person does not feel a strong urge to push immediately. After full dilation, the person rests for a period, allowing natural uterine contractions and gravity to move the baby further down the birth canal. This passive descent can shorten the duration of active pushing later, conserving maternal energy.
While some experts still recommend waiting until 10 centimeters to prevent injury, research shows that following an earlier, instinctive urge to push, even before full dilation, may not increase the risk of adverse maternal or neonatal outcomes. Management of this early urge is becoming more individualized, allowing the birthing person to gently follow their body’s signal as long as the baby is tolerating the labor well.