Childbirth is divided into three stages, with delivery encompassing the final two: the expulsion of the baby and the subsequent delivery of the placenta. This sequence, known as a vaginal birth, requires a coordinated effort between the mother’s body and the medical team supporting her. This information offers an educational overview of the physiological sequence.
Preparing for the Delivery Phase
The delivery phase begins once the cervix reaches full dilation, which is 10 centimeters, marking the end of the first stage of labor. The cervix is fully open, allowing the baby to pass from the uterus into the birth canal. The baby’s descent is tracked using “station,” which describes the position of the baby’s head relative to the mother’s ischial spines in the pelvis.
Some individuals may feel a powerful, involuntary urge to push, often described as a fetal ejection reflex, which signals the passive phase of the second stage. For those who have received an epidural, the sensation may be muted. In these cases, “laboring down” is encouraged, involving waiting for contractions to move the baby further down the birth canal before active pushing begins.
The mother and her support team choose optimal birthing positions that leverage gravity and open the pelvis. Positions like squatting, side-lying, or semi-reclined help align the baby for a smoother passage. The medical team continuously monitors the baby’s heart rate and descent to ensure the well-being of both the mother and child before active pushing begins.
The Pushing and Birth Sequence
The active second stage of labor is characterized by the mother’s expulsive efforts, guided by the healthcare provider or the mother’s own physiological urges. Two main techniques are commonly used: directed pushing and open-glottis pushing. Directed pushing, also called the Valsalva maneuver, involves holding the breath and bearing down forcefully during a contraction.
Open-glottis pushing, often called physiologic pushing, encourages the mother to follow her natural urge to bear down while exhaling or making noise. This method may reduce maternal fatigue and promotes a slower descent of the baby, which can reduce the risk of perineal tearing. The baby’s journey through the pelvis involves precise maneuvers known as the cardinal movements of labor, including descent, flexion, and internal rotation.
As the baby’s head moves deeper, it rotates internally to align its widest diameter with the widest part of the mother’s pelvis. The head then extends as it passes beneath the pubic bone, and the widest part of the head becomes visible at the vaginal opening, known as crowning. To manage intense stretching and prevent severe tearing, the provider may apply warm compresses or gentle counter-pressure to the perineum, referred to as “guarding.”
Once the head is delivered, it performs restitution, or external rotation, turning to align with the baby’s shoulders still inside the pelvis. The provider applies gentle downward traction to help the anterior shoulder slide under the pubic bone. Upward traction then delivers the posterior shoulder, and the rest of the baby’s body quickly follows, marking the moment of birth.
Immediate Post-Birth Procedures
The moments immediately following the baby’s expulsion focus on the initial assessment and stabilization of the newborn. The first action is typically to dry the baby thoroughly with warm towels; this tactile stimulation helps clear the airway and prevent rapid heat loss. Once dried, the baby is placed directly onto the mother’s chest for skin-to-skin contact, which aids in stabilizing the newborn’s heart rate, breathing, and temperature.
Attention then turns to the umbilical cord, which connects the baby to the placenta. Delayed cord clamping is often employed, meaning the cord is not clamped and cut until at least one minute after birth, or until pulsations have ceased. This allows a final transfer of oxygenated, iron-rich blood from the placenta to the newborn.
A standardized tool called the Apgar score is used to quickly evaluate the baby’s transition to life outside the womb. This scoring system assesses five factors:
- Appearance (skin color)
- Pulse (heart rate)
- Grimace (reflexes)
- Activity (muscle tone)
- Respiration (breathing effort)
The score is calculated at one minute and again at five minutes after birth; a score of seven or above indicates a good condition.
Simultaneously, the mother receives immediate care, including a thorough inspection of the perineum and vagina. Any tears or lacerations that occurred during birth are assessed and repaired with sutures by the healthcare provider. This tissue repair is performed promptly to control bleeding and promote optimal healing.
The Final Stage: Placental Delivery
The third stage of delivery is the expulsion of the placenta, often called the afterbirth. This stage begins immediately after the baby is born and concludes with the complete delivery of the placenta and its attached membranes. The uterus must contract strongly to shear the placenta from the uterine wall, indicated by several observable signs.
Signs of separation include a fresh gush of blood from the vagina, a lengthening of the umbilical cord, and the uterus changing shape to a firmer, globular mass. Healthcare providers employ active management to reduce the risk of postpartum hemorrhage. This involves administering a uterotonic medication, typically oxytocin, to encourage the uterus to contract forcefully.
Once signs of separation are observed, the provider may apply gentle, controlled traction on the umbilical cord while placing counter-pressure above the pubic bone to support the uterus. This action, combined with the mother’s mild pushes, guides the detached placenta out of the birth canal. After delivery, the placenta is inspected to ensure it is whole and that no fragments remain inside the uterus, which could cause infection or bleeding.
The final step involves the provider performing a firm fundal massage, manually rubbing the top of the uterus through the abdominal wall. This technique stimulates the uterine muscles to maintain a firm, contracted state. This action clamps down on the blood vessels where the placenta was attached and prevents excessive blood loss.