The process of childbirth, known as labor, is divided into four distinct stages that facilitate the delivery of a baby through the birth canal. This guide outlines the steps of a vaginal delivery, beginning with preparatory changes in the cervix and culminating in immediate postpartum recovery. Understanding these stages offers insight into the body’s coordinated effort to bring pregnancy to its conclusion.
The First Stage of Labor: Dilation and Effacement
The longest stage of labor begins with the onset of regular contractions and concludes when the cervix is fully dilated to 10 centimeters. This phase is characterized by effacement, the thinning of the cervix, and dilation, the opening of the cervix. The first stage is divided into three progressive phases, marked by changes in contraction intensity and cervical progress.
Latent Phase
The latent phase is the initial period, during which the cervix dilates slowly from zero to about six centimeters. Contractions are mild, short, and can be irregular, typically lasting 30 to 50 seconds and occurring every five to 20 minutes. Because this phase can last for many hours, most people remain at home, focusing on rest and light activity. Effacement, the softening and shortening of the cervix, is often completed during this early stage.
Active Phase
The active phase is marked by an increase in the strength and frequency of contractions. Contractions become more regular, generally occurring every three to five minutes and lasting between 50 and 60 seconds. The cervix dilates more quickly, progressing from six to eight centimeters. This is often the time to move to a hospital or birthing center, as the intensity of the contractions makes coping more challenging.
Transition Phase
The transition phase is the final part of the first stage, progressing from eight to 10 centimeters of dilation. This is the shortest but most intense period. Contractions are powerful and long, lasting 60 to 90 seconds with only a brief rest period in between. A person may experience symptoms like nausea, shaking, or a strong sensation of pressure in the rectum. Once the cervix reaches 10 centimeters of dilation, the first stage is complete, and the body is ready for delivery.
The Second Stage of Labor: Pushing and Delivery
The second stage begins when the cervix is fully dilated and ends with the birth of the baby. The baby begins descent through the pelvic bones and into the vaginal canal. The contractions, which focused on dilation in the first stage, now become expulsive, helping to move the baby downward.
Many people feel an involuntary urge to bear down, often described as an intense need for a bowel movement. This reflex, sometimes called the fetal ejection reflex, is triggered by the baby’s head pressing on the nerves in the pelvic floor. The healthcare team may encourage either directed pushing, where the person holds their breath and pushes on instruction, or spontaneous pushing, where the person follows their body’s natural urge.
As the baby descends, the head moves into view at the vaginal opening, known as crowning. Crowning can cause a temporary, burning sensation as the perineal tissue stretches around the largest diameter of the baby’s head. The team may ask for slow, controlled pushing or panting to allow the tissues to stretch gradually, minimizing the risk of tearing.
Once the head is delivered, the provider gently guides the head to allow the shoulders to rotate and pass through the pelvis. A final push is typically all that is needed to deliver the rest of the baby’s body, which slips out quickly after the shoulders are free. The second stage concludes the moment the baby is fully delivered.
The Third Stage of Labor: Delivery of the Placenta
Immediately following the baby’s birth, the third stage of labor commences, focusing on the expulsion of the placenta and its membranes, known as the afterbirth. This stage is significantly shorter than the first two, typically lasting five to 30 minutes. The uterus continues to contract, causing the placenta to detach from the uterine wall.
Signs that the placenta has separated include a sudden gush of blood from the vagina, the umbilical cord lengthening outside the body, and the uterus changing shape and becoming firmer. The person delivering the baby may be asked to give a gentle push to help expel the placenta once it is fully detached.
The umbilical cord is clamped and cut during this stage. Delayed cord clamping involves waiting for the cord to stop pulsating, typically one to three minutes after birth, to allow for a beneficial transfer of blood to the newborn. After the placenta is delivered, the healthcare provider examines it to ensure it is complete and that no fragments remain inside the uterus, which could cause excessive bleeding.
The Fourth Stage of Labor: Immediate Postpartum Recovery
The final stage of labor encompasses the first one to four hours following the delivery of the placenta, focusing on stabilizing the body and initiating bonding. The primary concern is monitoring the risk of postpartum hemorrhage, which is controlled by ensuring the uterus contracts firmly. The large blood vessels that connected the placenta to the uterine wall must be compressed by the muscle fibers to prevent excessive bleeding.
To stimulate these contractions, a healthcare provider performs a fundal massage, which involves firmly rubbing the top of the uterus through the abdomen. This technique helps the uterus “clamp down” and return to a firm state, and it is performed frequently in the first hour or two after birth. The provider also assesses the amount of vaginal bleeding, called lochia, to ensure it remains within a normal range.
This stage is the optimal time for skin-to-skin contact, often called kangaroo care, where the baby is placed directly on the chest. This contact helps regulate the newborn’s temperature and blood sugar and promotes the release of oxytocin, which aids in uterine contraction and bonding. The initial attempt at breastfeeding often occurs during this window, further stimulating oxytocin release and encouraging the uterus to continue its shrinking process.