Normal Spontaneous Vaginal Delivery
|Normal Spontaneous Vaginal Delivery a.k.a. Vaginal Birth, Spontaneous Vaginal Delivery (SVD), Normal Vaginal Delivery, is the term used to describe any delivery of the baby through the vagina. The baby typically comes through head first. If the baby is not head first, (e.g., breech) it may need to be delivered by c-section.|
Stages of Labor
First stage of labor
A typical human childbirth will begin the onset of the first stage of labor: contractions of the uterus, at first every 10-30 minutes and lasting about 40 seconds each. Occasionally the labor will begin with a rupture of the amniotic sac, the paired amnion and chorion (“breaking of the water”). The contractions will accelerate until they happen every two minutes. Each contraction dilates the cervix until it reaches 10 centimeters (4″) in width.
The duration of labor varies wildly, but averages some 13 hours for women giving birth to their first child (“primiparae”) and 8 hours for women who have already given birth.
Second stage of labor
In the second stage of labor, the baby is expelled from the womb through the birth canal by both the uterine contractions and by powerful abdominal contractions (“bearing down”). The baby is most commonly born head-first. With difficulty, babies can be delivered in the “breech” position where the baby’s buttocks or feet are delivered first and the legs are folded onto the baby’s body. Babies in a “footling breech” position should not be delivered via vaginal birth.
Immediately after birth, the child undergoes extensive physiological modifications as it acclimatizes to independent breathing. Several cardiac structures start regressing immediately after birth, such as the ductus arteriosus and the foramen ovale.
The medical condition of the child is assessed with the Apgar score, based on five parameters. A “good start” refers to higher scores, while a child doing poorly will have low scores that do not improve rapidly over time.
Third stage (placental)
After the birth
When the amniotic sac has not ruptured during labor or pushing, the infant can be born with the membranes intact. This is referred to as “being born in the caul.” The caul is harmless and easily wiped away by the doctor or person assisting with the childbirth. In medieval times, a caul was seen as a sign of good fortune for the baby, in some cultures was seen as protection against drowning, and the caul was often impressed onto paper and stored away as an heirloom for the child. With the advent of modern interventive obstetrics, premature artificial rupture of the membranes has become common and it is rare for infants to be born in the caul in Western births.
Due to the relatively-large size of the human skull and the shape of the human pelvis forced by the erect posture, childbirth is more difficult and painful for human mothers than other mammals. Many methods are available to reduce the pain of labor, including psychological preparation, emotional support, epidural analgesia, spinal anesthesia, nitrous oxide and opioids, the Lamaze Technique. Each method has its own advantages and disadvantages.
Complications occasionally arise during childbirth; these generally require management by an obstetrician.
Non-progression of labor (longterm contractions without adequate cervical dilation) is generally treated with cervical prostaglandin gel or intravenous synthetic oxytocin preparations. If this is ineffective, Caesarean section may be necessary.
Fetal distress is the development of signs of distress by the child. These may include rising or decreasing heartbeat (monitored on cardiotocography/CTG), shedding of meconium in the amniotic fluid, and other signs.
Non-progression of expulsion (the head or presenting parts are not delivered despite adequate contractions): this can require interventions such as vacuum extraction, forceps extraction and Caesarean section.
In modern times, participation of the father during childbirth is now the norm. However, before the 1960’s, in most cultures the father was forbidden to enter childbirth area, as were other men with the exception of the doctor.