Why do you only press during contractions

 General information about normal childbirth


The triggering cause of the birth is still unknown. It is believed that certain hormonal changes at the end of pregnancy triggered the birth. In any case, normal birth begins when the child is optimally adapted to life outside the uterus. Heralds that point to the approaching birth are, for example, a lowering of the body, which reduces the pregnant woman's shortness of breath, as well as a change in position of the child, in which the head enters the small pelvis. When labor begins, there is often a discharge of mucus from the cervix. The woman is mentally unstable, sleeps poorly and has felt increased pressure on the bladder and intestines. The child's movements subside and regular contractions every 10 minutes for at least 2 hours can be observed. At this stage the amniotic sac cracks and the cervical canal begins to widen. Although childbirth is a functional unit, it is useful for explanation to break it down into individual sections:


  1. Opening period
  2. Expulsion period
  3. Placental period
  4. Postplacental period

The course of these stages of normal birth is essentially determined by the following factors:

  • the child (birth object)
  • the path to be covered (birth canal)
  • the driving forces (labor pains).

Normal birth ends 2 hours after the placenta, i.e. the placenta, is expelled.


A birth is considered normal if the child is born from the anterior occipital position (see below) after a gestation period of 259 to 293 days and a birth period of 3 to 18 hours. In addition, the amniotic sac jumps during the opening period, the mother's blood loss does not exceed 500 ml and the mother and child are not significantly endangered during childbirth.

Birth object

The examination of the pregnant woman by the obstetrician, this can be a doctor or a midwife, allows a statement to be made about the position of the child. For example, the height of the uterus, the position of the head, the axis in which the child is located (lengthways or crossways) are assessed. The most important part in obstetrics, because it is the most extensive part of the child, is the head. It can only deform a little and adapt to the narrow birth canal. Flat gaps in the bones, the fontanelles, which can be felt by the obstetrician during the internal examination, provide important orientation information on the position of the head. The large fontanel behind the forehead is square, while the small fontanel on the back of the head is triangular in shape. The head bent with the chin on the chest has the smallest circumference and requires the least space. If the small (triangular) fontanel can be felt in the woman giving birth, the child has correctly positioned itself in the birth canal with its head bent. The other parts of the child are more malleable and take on the shape of a cylinder (birth roller) due to the forces acting during the birth. The arms are crossed in front of the chest, the shoulders are pushed up towards the neck and the thighs are strongly bent, crossed and pressed against the stomach.

Depending on the alignment of the child's body axis to the mother's axis, a distinction is made between longitudinal positions (99.5% of all births) and oblique and transverse positions (0.5% of all births). Within the longitudinal positions there are the cranial positions and the breeches (very rare). A normal birth is possible from the longitudinal positions, while oblique and transverse positions represent positions incapable of childbearing. In this case, the woman should be admitted to the hospital 2 weeks before the due date. Fig .: Fetus in the 28th week of pregnancy

Birth canal

The birth canal consists of the bony pelvis and a so-called soft tissue attachment tube (cervix, vagina, pelvic floor). Most important for the mechanics of childbirth are the bony conditions in the small pelvis. The pelvic entrance is transversely oval, the center of the pelvis is round and the pelvic exit is then again longitudinally oval. During the passage through the birth canal, the child adapts to these requirements by turning it like a screw. The width of the pelvic entrance determines whether a normal birth is possible at all. You orient yourself here by the distance between the rear edge of the pubic bone and the upper edge of the sacrum, which should be 11 cm. During the birth, the sacroiliac joints and the two pubic branches have become mobile within certain limits due to hormonal influences. This loosening of the pelvic ring can increase the distance mentioned above by up to 1 cm. The tailbone can also move backwards by approx. 2 cm during birth.


Labor pains


The rhythmic contractions of the uterus during pregnancy are known as labor. Contractions that occur before the 30th week of pregnancy are called pregnancy contractions. They are painless and the pregnant woman feels them as hardening. After the 30th week of pregnancy, pre- or sinking pains occur, which occur irregularly and are slightly painful. They cause the lower parts of the uterus and the cervix to expand. The transition into labor pains during childbirth is fluid. In normal birth, the frequency and strength of labor increases with the opening of the cervix. After each contraction, the muscle fibers of the uterus no longer return to their original length, but remain somewhat shortened. In the opening period 1-3 contractions per 10 minutes, in the expulsion period up to 5 contractions per 10 minutes are observed. During the opening period, pressures of approx. 6.6 kPa (50 Torr) occur in the uterus, whereas during the expulsion period pressures of up to 20 kPa (150 Torr) are achieved due to the additional involvement of the abdominal muscles (abdominal press). After labor is over, there is after-labor that leads to the expulsion of the placenta.

Periods of childbirth

Opening period The opening period begins with the onset of regular labor and lasts until the cervix is ​​fully opened. It lasts between 10 and 12 hours for primiparous women, and is shortened to 6 to 7 hours for multiparous women. In this phase, the membranes tear (timely rupture of the bladder). The rupture of the bladder creates a suction effect on the child's head, which can lead to the development of a so-called birth tumor. This harmless swelling disappears within a few days after the birth. If the amniotic sac ruptures before labor begins, it is a premature rupture of the bladder. If the rupture of the bladder is delayed until the expulsion period, one speaks of a delayed rupture of the bladder. Most women go to hospital at this stage or call their midwife if a home birth is planned. It is the job of the obstetrician to use the questioning and examination of the pregnant woman to clarify whether a normal or a high-risk birth is to be expected and to take the appropriate precautions. The following nursing measures should be carried out in preparation for the birth:

  • Bowel movement (possibly through enema)
  • Body cleansing with a warm full bath or shower
  • Shortening or shaving the pubic hair (location of germs!)
  • Disinfection of the external genital organs
  • comfortable positioning of the woman in labor



Expulsion period The expulsion period begins with the full opening of the cervix and ends with the birth of the child. It lasts between 60 and 75 minutes for primiparous women, and is shortened to 20 to 30 minutes for multiparous women. When the child's head is kicked so deep that it presses on the pelvic organs, the urge to press is triggered. This compulsion to press along during labor drives the child forward. The expulsion period is the most dangerous phase during childbirth for the child. The child's heartbeat should be checked continuously, at least after each contraction. The danger is a reduction in the oxygen supply to the child due to reduced placental blood flow and increased intracerebral pressure due to compression of the head due to the high resistance of the pelvic floor. At this point, an episiotomy may be necessary because it protects the pelvic floor from overstretching and tearing, as well as reducing the pressure on the child's head and shortening the expulsion period. In any case, perineal protection must be carried out manually by the midwife or obstetrician in order to prevent the head from being pushed out too quickly, as the child's skull should be relieved of pressure slowly (risk of cerebral hemorrhage). After the head is born, the trunk follows without any problems, as it has a smaller diameter than the head and can be deformed very well. The nasopharynx is then suctioned off and the child is cut off.

Placental period The placental period begins with the birth of the child and ends with the expulsion of the placenta. This postpartum period is the most dangerous part of the birth for the mother because of the high risk of bleeding. The afterbirth pains lead to a constant shrinking of the uterus, which leads to a decrease in the placental attachment point. This shift in area causes the placenta to become detached from the uterus. This detachment begins mainly in the center, less often at the edge of the placenta. There are classic signs that indicate a solution of the placenta:

Edging mark according to Schröder: The previously spherical uterus becomes narrow and angular and stands with its fundus 2 to 4 transverse fingers above the navel.

Umbilical cord signs according to Ahlfeld: A ribbon attached to the umbilical cord at the level of the external genitals immediately after birth slides approx. 10 cm lower.

Solution according to Küster: If you press the abdominal wall above the pubic bone with the edge of your hand, the umbilical cord does not retract into the vagina.

When the placenta has completely loosened, it is born by the woman pressing along with it. This process takes about 20 minutes in total. If the woman's abdominal press is insufficient, the obstetrician can help expel the placenta by compressing the abdominal wall from the outside or by pulling on the umbilical cord. During the placental period, blood loss should not exceed 500 ml. It is now more and more common to observe the so-called active management of the placental period. It includes the drug-based stimulation of the after-pains up to expulsion of the placenta and then the drug-based support of the permanent contraction of the uterus in order to achieve hemostasis. In this way the placental period is shortened to approx. 10 minutes and the blood loss can generally be reduced to 200 ml. It is very important to check the placenta for completeness, as residues left in the uterus can lead to severe bleeding and infections.

Post-placental period After the placenta has been expelled, the woman should be observed for about 2 hours, at which point the birth is considered to have ended. During this time, the hemostasis in the uterus is monitored. In any case, an examination of the soft tissues of the birth canal (cervix, vagina, pelvic floor, perineum) is recommended in order to diagnose and treat injuries as early as possible.