A vaginal delivery is the birth of offspring in mammals (babies in humans) through the vagina (also called the "birth canal"). [1] It is the most common method of childbirth worldwide. [2] It is considered the preferred method of delivery, with lower morbidity and mortality than caesarean sections (C-sections). [3]
70% of births in the United States in 2019 were vaginal deliveries. [4]
80% of births globally in 2021 were vaginal deliveries, with rates varying from 95% in sub-Saharan Africa to 45% in the Caribbean. [2]
Benefits for the mother include
Benefits for the infant include:
Different types of vaginal deliveries have different terms:
A normal vaginal delivery (NVD) is defined as any vaginal delivery, assisted or unassisted. [13]
Labor is characterized by uterine contractions which push the fetus through the birth canal and results in delivery. [14] Labor is divided into three stages.
Complications of vaginal delivery can be grouped into the following criteria; failure to progress, abnormal fetal heart rate tracing, intrapartum hemorrhage, and post-partum hemorrhage.
Failure to progress occurs when the labor process slows or stops entirely, indicated by slowed cervical dilation. [3] Factors that place a woman's pregnancy at higher risk include advanced maternal age, Premature Rupture of Membranes (PROM) and induction of labor. [17] Pitocin, a synthetic version of oxytocin, is often administered to induce labour. [1] Oxytocin is a natural hormone and a uterotonic agent which stimulates the uterine muscles to contract and initiate labour. [18] Cesarean section is also commonly considered when the pregnancy fails to progress. [19] With a cesarean section, there is a higher chance that the uterus will become infected or that thromboembolic complications will occur. [12] There is also a higher chance of death. [19]
Abnormal fetal heart tracing suggests that the fetus's heart rate has slowed during labor due to head compression, cord compression, hypoxemia or anemia. [3] Uterine tachysystole, the most common adverse effect of oxytocin (usually as a result of a problematic dosage), can result in nonreassuring fetal heart tracing. It can usually be reversed when oxytocin infusion is decreased or stopped. [20] If the abnormal fetal heart rate persists, and uterine tachysystole continues, tocolytic remedies, such as terbutaline, may be used. Afterward, if beneficial and uterine tone has returned to baseline and fetal status is stable, oxytocin as a labor augmenting agent may be resumed. [21] The persistence of an abnormal fetal heart rate may also indicate that a cesarean section is necessary. [22]
Intrapartum hemorrhage is characterized by the presence of copious blood during labor. The bleeding may be due to placental abruption, uterine rupture, placenta accrete, undiagnosed placenta previa, or vasa previa. [3] Cesarean section is indicated.
Post-partum hemorrhage is defined by the loss of at least 1,000 mL of blood accompanied with symptoms of hypovolemia within 24 hours after delivery. Typically, the first symptom is excessive bleeding accompanied by tachycardia. Significant loss of blood may also result in hypotension, nausea, dyspnea, and chest pain. [23] It is estimated that between 3% and 5% of women giving birth vaginally will experience post-partum hemorrhage. Risk factors include fetal macrosomia, pre-eclampsia, and prolonged labor. [23] Prevention consists of administering oxytocin (Pitocin) at delivery and early umbilical cord clamping. [24] Post-partum hemorrhage is usually attributed to uterus atony, when the uterus fails to contract after delivering the baby. [25]
As a result of discrepancies in diagnostic criteria and human variability, there is wide variation in data on maternal and fetal death associated with poor progress. [19]
More than 1 in 10 women with assisted vaginal births develop an infection. [26] Preventive antibiotics are recommended to women who have had an assisted vaginal birth by the World Health Organization. [27] An analysis has showed that preventive antibiotics reduce the risk of infection after an assisted vaginal birth, irrespective of whether a woman has had a perineal tear, an episiotomy, or both. Delays in receiving antibiotics also increases the risk of infection. [28] [29]
Spontaneous vaginal delivery at term is the preferred outcome of pregnancy, and according to the International Federation of Gynecology and Obstetrics, will be recommended if there are no evidence-based clinical indications for Cesarean section. [30] However, there are some contraindications for vaginal delivery that would result in conversion to Cesarean delivery. The decision to switch to Cesarean delivery is made by the health care provider and mother and is sometimes delayed until the mother is in labor.
Breech birth presentations occur when the fetus's buttocks or lower extremities are poised to deliver before the fetus's upper extremities or head. The three types of breech positions are footling breech, frank breech, and complete breech. These births occur in 3% to 4% of all term pregnancies. [31] They usually result in Cesarean sections because it is more difficult to deliver the baby through the birth canal and there is a lack of expertise in vaginal breech delivery and therefore fewer vaginal breech deliveries performed. It is also associated with cord prolapse and an elevated risk for birth defects in breech babies. [31] Controversy and debate surround the topic due to different views on the preferred route of delivery when breech presentation occurs. [31] [32] Some health professionals believe that vaginal breech delivery can be a safe alternative to planned Cesarean in certain instances. [31]
Complete placenta previa occurs when the placenta covers the opening of the cervix. If placenta previa is present at the time of delivery, vaginal delivery is contraindicated because the placenta is blocking the fetus's passageway to the vaginal canal.
Herpes simplex virus with active genital lesions or prodromal symptoms is a contraindication for vaginal delivery so as to avoid mother-fetal transfer of HSV lesions.
Untreated human immunodeficiency virus (HIV) infection is a contraindication for vaginal delivery to avoid mother-fetal transfer of human immunodeficiency virus. [33]
Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen. It is often performed because vaginal delivery would put the mother or child at risk. Reasons for the operation include obstructed labor, twin pregnancy, high blood pressure in the mother, breech birth, shoulder presentation, and problems with the placenta or umbilical cord. A caesarean delivery may be performed based upon the shape of the mother's pelvis or history of a previous C-section. A trial of vaginal birth after C-section may be possible. The World Health Organization recommends that caesarean section be performed only when medically necessary.
Childbirth, also known as labour, parturition and delivery, is the completion of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million human births globally. In the developed countries, most deliveries occur in hospitals, while in the developing countries most are home births.
A breech birth is when a baby is born bottom first instead of head first, as is normal. Around 3–5% of pregnant women at term have a breech baby. Due to their higher than average rate of possible complications for the baby, breech births are generally considered higher risk. Breech births also occur in many other mammals such as dogs and horses, see veterinary obstetrics.
Placenta praevia is when the placenta attaches inside the uterus but in a position near or over the cervical opening. Symptoms include vaginal bleeding in the second half of pregnancy. The bleeding is bright red and tends not to be associated with pain. Complications may include placenta accreta, dangerously low blood pressure, or bleeding after delivery. Complications for the baby may include fetal growth restriction.
A hysterotomy is an incision made in the uterus. This surgical incision is used in several medical procedures, including during termination of pregnancy in the second trimester and delivering the fetus during caesarean section. It is also used to gain access and perform surgery on a fetus during pregnancy to correct birth defects, and it is an option to achieve resuscitation if cardiac arrest occurs during pregnancy and it is necessary to remove the fetus from the uterus.
Placental abruption is when the placenta separates early from the uterus, in other words separates before childbirth. It occurs most commonly around 25 weeks of pregnancy. Symptoms may include vaginal bleeding, lower abdominal pain, and dangerously low blood pressure. Complications for the mother can include disseminated intravascular coagulopathy and kidney failure. Complications for the baby can include fetal distress, low birthweight, preterm delivery, and stillbirth.
Antepartum bleeding, also known as antepartum haemorrhage (APH) or prepartum hemorrhage, is genital bleeding during pregnancy after the 28th week of pregnancy up to delivery.
Bloody show or show is the passage of a small amount of blood or blood-tinged mucus through the vagina near the end of pregnancy. It is caused by thinning and dilation of the cervix, leading to detachment of the cervical mucus plug that seals the cervix during pregnancy and tearing of small cervical blood vessels, and is one of the signs that labor may be imminent. The bloody show may be expelled from the vagina in pieces or altogether and often appears as a jelly-like piece of mucus stained with blood. Although the bloody show may be alarming at first, it is not a concern of patient health after 37 weeks gestation.
Obstetrical bleeding is bleeding in pregnancy that occurs before, during, or after childbirth. Bleeding before childbirth is that which occurs after 24 weeks of pregnancy. Bleeding may be vaginal or less commonly into the abdominal cavity. Bleeding which occurs before 24 weeks is known as early pregnancy bleeding.
Uterine rupture is when the muscular wall of the uterus tears during pregnancy or childbirth. Symptoms, while classically including increased pain, vaginal bleeding, or a change in contractions, are not always present. Disability or death of the mother or baby may result.
Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.
Cervical effacement or cervical ripening refers to the thinning and shortening of the cervix. This process occurs during labor to prepare the cervix for dilation to allow the fetus to pass through the vagina. While this a normal, physiological process that occurs at the later end of pregnancy, it can also be induced through medications and procedures.
Placenta accreta occurs when all or part of the placenta attaches abnormally to the myometrium. Three grades of abnormal placental attachment are defined according to the depth of attachment and invasion into the muscular layers of the uterus:
Uterine atony is the failure of the uterus to contract adequately following delivery. Contraction of the uterine muscles during labor compresses the blood vessels and slows flow, which helps prevent hemorrhage and facilitates coagulation. Therefore, a lack of uterine muscle contraction can lead to an acute hemorrhage, as the vasculature is not being sufficiently compressed. Uterine atony is the most common cause of postpartum hemorrhage, which is an emergency and potential cause of fatality. Across the globe, postpartum hemorrhage is among the top five causes of maternal death. Recognition of the warning signs of uterine atony in the setting of extensive postpartum bleeding should initiate interventions aimed at regaining stable uterine contraction.
In case of a previous caesarean section a subsequent pregnancy can be planned beforehand to be delivered by either of the following two main methods:
A shoulder presentation is a malpresentation at childbirth where the baby is in a transverse lie, thus the leading part is an arm, a shoulder, or the trunk. While a baby can be delivered vaginally when either the head or the feet/buttocks are the leading part, it usually cannot be expected to be delivered successfully with a shoulder presentation unless a cesarean section (C/S) is performed.
A uterotonic, also known as an oxytocic or ecbolic, is a type of medication used to induce contraction or greater tonicity of the uterus. Uterotonics are used both to induce labor and to reduce postpartum hemorrhage.
Uterine Tachysystole is a condition of excessively frequent uterine contractions during pregnancy. It is most often seen in induced or augmented labor, though it can also occur during spontaneous labor, and this may result in fetal hypoxia and acidosis. This may have serious effects on both the mother and the fetus including hemorrhaging and death. There are still major gaps in understanding treatment as well as clinical outcomes of this condition. Uterine tachysystole is defined as more than 5 contractions in 10 minutes, averaged over a 30-minute period.
Prolonged labor is the inability of a woman to proceed with childbirth upon going into labor. Prolonged labor typically lasts over 20 hours for first time mothers, and over 14 hours for women that have already had children. Failure to progress can take place during two different phases; the latent phase and active phase of labor. The latent phase of labor can be emotionally tiring and cause fatigue, but it typically does not result in further problems. The active phase of labor, on the other hand, if prolonged, can result in long term complications.
Emergency childbirth is the precipitous birth of an infant in an unexpected setting. In planned childbirth, mothers choose the location and obstetric team ahead of time. Options range from delivering at home, at a hospital, a medical facility or a birthing center. Sometimes, birth can occur on the way to these facilities, without a healthcare team. The rates of unplanned childbirth are low. If the birth is imminent, emergency measures may be needed. Emergency services can be contacted for help in some countries.