Vaginal Delivery (Normal Delivery)

Birth is defined as the process of expulsion of the baby and its tissues (such as placenta, cord, amniotic membrane) from the uterus (37-42 weeks of gestation) when the time comes.

Characteristics of birth

The diagnosis of labour is important as it indicates the beginning of the labor process.

The diagnosis of labour is based on regular painful uterine contractions accompanied by opening of the cervix (cervical canal), effacement (effacement) and expulsion of the cervical mucus plug (engorgement).

There are three phases of labor.

1. First stage - From the beginning of labor until the full opening of the cervix.

2. Second stage - From the full dilatation of the cervix until the baby comes out of the vagina.

3. Third stage - From the baby's exit from the vagina until the placenta is expelled.

It is characterized by softening, wiping and then dilatation (opening and dilation of the cervix) in the cervix, which we call cervical maturation.

The cervical canal, which is normally tubular, is erased and dilated and becomes the lower segment of the uterus. These cervical changes are caused by regular uterine contractions.

Mechanical features of labor

There are three basic mechanical features of labor.

1-Power

It is the force created by contraction to expel the baby from the uterus. In labor, active uterine contractions occur every 2-3 minutes and last 40-60 seconds.

These contractions (labor pains) cause the cervix to dilate and dilate, allowing the presenting part of the baby to descend downwards.

In general, contractions are less regular and more irregular in women who have not given birth before than in women who have.

2- Pathway

In labor, the baby crosses the pelvis (pelvic bone) transversely.

Therefore, pelvic diameters should be evaluated in detail.

There are two diameters of the pelvic inlet:

a. The transverse diameter is usually 13 cm.

b. The anteroposterior (AP) diameter is 11 cm on average.

The pelvic outlet is the opposite of 11 cm transverse diameter and 13 cm anteroposterior diameter.

The protrusions of the ischiadic bone, which we call the spina ischialis, can also be palpated vaginally.

The descent and position (above or below in cm) of the fetal presenting part relative to the spina

ischialis line is indicated.

The 3rd passenger is the baby.

The diameter of the baby's head is important for the baby's head to move downwards.

A normal sized fetal head rarely causes an obstruction.

The baby's head has a wiggling structure and the bony junction lines may overlap each other to adapt to the birth canal as the head moves through the birth canal and this can be palpated during vaginal examination. During labor, the head is affected by cervical pressure and swells and edematous, a condition called hooding.

Progression of labor

The most important step in the progression of labor is cervical dilation and the baby's head descending downwards. The progression of labor differs between primiparous (first time laborers) and multiparous (previous laborers). Labor is often slow in primiparous women, but labor can also progress slowly in multiparous women.

Progression of labor in primiparous women

Primiparous women have at least 1 cm cervical dilatation in 1 hour.

Therefore, the first phase lasts for 10 hours and the second phase for 2 hours.

Prolonged labor is considered when labor lasts more than 12 hours.

In primiparous women, contractions and progression of labor are said to be ineffective because the uterus has no previous experience of labor, and although contractions are frequent and severe, cervical dilation is minimal.

In the early period, while the membranes have not yet opened, labor can be accelerated when

oxytocin infusion (artificial labor) is given to open the amniotic membrane and support labor.

Close NST monitoring should be done to ensure that contractions are not more frequent than 2 minutes. Excessive uterine contraction may cause fetal hypoxia by decreasing placental blood flow in the mother.

If 12 hours have passed and full cervical dilation has not yet occurred, cesarean delivery is appropriate to reduce the risk of increased fetal hypoxia and to relieve maternal exhaustion that prevents progression of labor. The critical indicator of progression of labor is the partogram, the birth chart.

Progression of labor in multiparous women

The multiparous uterus contracts sufficiently because of previous labor experience. However, in some multiparous cases, despite previous labor, it does not contract sufficiently, just like in the primiparous uterus (previous cesarean section). Multiparous women may also have slow progression of labor, the main cause of which may be a large baby or malposition. A multiparous uterus is more prone to obstetric complications and therefore the use of oxytocin should only be decided after careful evaluation.

Assessment of fetal well-being in labor

The main purpose of fetal monitoring in labour (NST) is to determine the oxygen adequacy of the fetus.

Each fetus responds differently to stress during labor, depending on its own reserve.

A fetus that is stressed in the womb is more likely to be stressed during vaginal labor.

1-Amniotic Fluid Quantity and Color; It is important in labor monitoring to determine the oxygen levels and well-being of the baby.

Absence of amniotic fluid may be associated with intrauterine growth retardation (IUGR). Meconium is when the fetus passes its first stool in the womb.

Babies pass their first stool after birth. Babies can also make meconium while in the womb if the baby is exposed to any stress while in the womb or during labor. Meconium is one of the indicators that the baby has been exposed to stress inside the womb. If the labor is short and the baby's heart rate is within normal limits, vaginal delivery is continued. If not, cesarean delivery is performed quickly.

Grade 1 meconium is when the amniotic fluid is stained with light meconium (well diluted with amniotic fluid),

Grade 2 moderate staining,

Grade 3 is defined as heavy, thick staining and the appearance of fresh meconium fragments with decreased amniotic fluid, a sign of fetal hypoxia.

2-Follow-up on NST

NON STRESS TEST is a test that evaluates the relationship between the baby's heart rhythm and labor pains and assesses the baby's well-being in the womb.

During vaginal labor, the NST is connected at regular intervals to assess the baby's heart rhythm and the strength and frequency of labor pains.

Third stage of labor

The third stage of labor is the time from the birth of the baby to the exit of the placenta.

In the normal physiological process, the uterus continues to contract with the birth of the baby, reducing its surface area and facilitating the separation of the placenta from the uterine wall.

Some bleeding during this period often indicates that the placenta has detached.