Features of management of labor with placenta previa

Placenta previa is one of the most common causes of bleeding in women during late pregnancy and during childbirth.

Placenta previa is a complication that is associated with an improper placement of a child's place in the uterus. In normal conditions, the placenta is located within the uterine body on the anterior or posterior wall of the uterus with a partial transition to the right or left surface of the uterus. The lower edge of the placenta is located above the inner pharynx of the cervix by 7-10 cm. This distance corresponds to the width of the lower segment of the uterus.

With at least partial location of the placenta in the region of the lower segment, the increasing stretching of the latter, observed during the period of preparation for the forthcoming birth and especially in the process of childbirth, leads to a detachment of its low-lying area. Progressive detachment of the placenta located in the region of the lower segment of the uterus leads to an increasingly increasing and often recurring bleeding.

Placenta previament affecting the inferior segment of the uterus is found in the following variants:

• low placental location, or low placenta - the placenta is located in the region of the lower segment of the uterus, and its margin is within 3-4 cm from the internal cervical pharynx;

• marginal placenta previa - the child's place is located in the lower segment, and its edge reaches the inner throat;

• lateral presentation of the placenta - the child's place does not completely cover the area of ​​the internal throat;

• complete, or central placenta previa - the inner throat is completely blocked by the placenta.

The marginal and lateral presentation of the child's place is designated as incomplete, or partial presentation of the placenta. Low attachment of the placenta is clinically manifested in the form of bleeding that occurs after the onset of regular birth pain. Bleeding in partial and especially full placenta previa usually begins long before the onset of labor - in the third trimester of pregnancy.

If, with an internal obstetrical examination performed necessarily with a deployed operating room, a complete placenta previa is diagnosed, then the delivery of the woman is performed exclusively by an operative route.

If the placenta previa is partial, then in the longitudinal position of the fetus and with uncommon uterine bleeding, it is possible for the birth to occur naturally. In this case, the shells that are not occupied by the placental tissue are opened to stop the further detachment of the present placental segment. If the head of the fetus is present, then after opening the fetal membranes, it enters the entry of the mother's pelvis, pressing the exfoliated portion of the placenta against the wall of the uterus and to the bone base of the entrance to the small pelvis. This usually leads to the cessation of bleeding. Sometimes, in order to obtain the effect, dermal head tongs are laid on the head of the fetus according to Wilt-Ivanov with a small weight suspended( no more than 200-300 g), which should facilitate the entry of the fetal head into the plane of the entrance to the small pelvis. A similar effect can be obtained with the lowering of the fetal pedicle with the pelvic presentation of the fetus. In this case, a gauze braid is hung on the lowered leg to enhance the effect and a small weight is suspended( 200-300 g).In the absence of effect from these measures and the continuation of bleeding according to vital indications, a cesarean section is performed.

If partial delivery of the placenta is carried out through the natural birth canal, then very carefully should resort to various delivery operations and benefits( applying obstetrical forceps to the head of the fetus, removing it from the pelvic end, removing the shoulder girdle and head with breech presentation, etc.).With the placenta previa, the tissues of the uterus at the place of attachment of the child's place are considerably thinned and loosened, and are therefore easily torn. Because of this, forced delivery, especially with incomplete opening of the uterine throat, can lead to deep ruptures of the cervix with a transition to the lower segment of the latter and, in the future, to the death of the parturient woman from profuse uterine bleeding.

In the case of deliveries through the natural birth canal in the presence of placenta previa, it is necessary to manually remove the placenta, to isolate the placenta and to examine the walls of the uterus immediately after the fetus is born for possible damage to the placenta. Allocated last carefully examined for confirmation of the diagnosis of placenta previa and clarification of the variant of this pathology. The exfoliated site of the placenta( in the place of its location above the internal pharynx) does not function. Depending on the area of ​​the exfoliated placenta, the intrauterine state of the fetus is deteriorating to some extent, and with a large area of ​​detachment, its death occurs. With the detachment of the present placenta, the villi of the chorion and the capillaries in which the fetal blood circulates are often damaged. Therefore, babies born with placenta previa are often anemic( anemic) and need blood transfusion to compensate for blood loss.

In physiological conditions, the normally located placenta begins to exfoliate only after the birth of the fetus, i.e.in the third, or consecutive, period of labor. Premature detachment of the normally located placenta, i.e.separation of it even before the onset of labor or during the first or second of their periods is a pathological phenomenon.