Premature detachment of the placenta

The etiology of premature placental abruption is not fully understood. A number of predisposing factors have been identified:
– high maternal blood pressure – chronic arterial hypertension (ie from before pregnancy) or pregnancy-related hypertension (pre-eclampsia).
– trauma;
– smoking;
– short umbilical cord – relatively or absolutely short. In the relatively shortened umbilical cord, it has wrapped around parts of the fetus. In the case of the absolutely short, its length is initially smaller – under 30-35 cm when it is attached to the bottom of the uterus, and under 20 cm when it is attached low.
– sudden decompression of the uterus – e.g. with premature rupture of the amniotic sac, birth of the first twin in a multiple pregnancy.
– myoma near the place of attachment of the placenta.
– a case of premature detachment of the placenta in a previous pregnancy.
– abortions – the endometrium is damaged.
– age under 20 or over 35

Pathoanatomy: Premature placental abruption can be partial or complete. When detachment occurs around the edge of the placenta, external bleeding occurs – the blood flows between the fetal membranes and the inner uterine surface. This is the more common option (80%). When central parts of the placenta detach, a hematoma forms between it and the uterus – retroplacental hematoma. In this case, there is no external bleeding, and the risk of coagulation disorders is higher. With complete premature detachment of the placenta, it is freely mobile in the uterine cavity together with the fetal membranes and the dead fetus.

Clinical picture of premature placental abruption:

The clinical symptoms of premature placental abruption are manifested differently depending on the localization, the amount of bleeding, etc.
The most characteristic symptoms are:
– vaginal bleeding (in 80%).
– pain – severe, stabbing pain in the uterus, pain in the abdomen or lower back. When the placenta detaches from the back wall of the uterus, localized pain may be absent.
– accelerated uterine contractions, constant tone of the uterus.
– lack of child movements – suffering/death of the fetus.
– manifestations of shock – pallor of the skin and mucous membranes, rapid heart rate, low blood pressure, collapse, impaired kidney function, etc. It is caused by blood loss, impaired coagulation (blood clotting), severe pain. Often the degree of shock does not correspond to the size of the hematoma – e.g. a small hematoma can lead to a serious condition.

Classification:

Placental abruption can be classified based on the degree of detachment (complete/partial), the site of detachment (marginal/central), according to the clinic. Clinical classification includes:

Grade 0 – no symptoms.

Class 1 – mild symptoms:
– mild to absent vaginal bleeding;
– slightly sensitive uterus;
– normal blood pressure and normal heart rate of the mother;
– no blood coagulation disorders;
– without suffering to the fetus.

Class 2 – moderate symptoms:
– moderate to absent vaginal bleeding;
– moderately to highly sensitive uterus with possible tetanic contractions;
– tachycardia in the mother, orthostatic hypotension (sudden drop in blood pressure when standing up);
– fetal distress;
– reduced fibrinogen (0.5-2.5g/l).

Class 3 – severe symptoms:
– heavy to absent vaginal bleeding;
– very painful tetanic shortened uterus;
– severe condition of the mother – shock;
– low fibrinogen (<1.5 g/l);
– impaired blood coagulation;
– fetal death.

Complications of premature placental abruption:

On the mother’s side:
– hemorrhagic diathesis (reduced blood clotting) – to DIC syndrome (disseminated intravascular coagulopathy). Placental thromboplastin is released, which activates the extrinsic pathway of blood coagulation. Coagulation factors are depleted (consumptive coagulopathy), platelets and fibrinogen decrease, plasminogen is activated, and fibrin degradation products appear.
– complications from blood loss – shock.
– complications related to blood transfusion.
– performing a caesarean section in the current and subsequent pregnancies.
– Couvelaire’s uterus (utero-placental apoplexy) – a life-threatening condition in which blood enters the musculature of the uterus and makes it less flexible.
– removal of the uterus (hysterectomy).
– death.

From the side of the fetus:
– insufficient intake of oxygen and nutrients – the transport surface of the placenta is reduced.
– premature birth.
– stillbirth.

Diagnosis: The diagnosis of premature detachment of the placenta is based on:
– history – presence of risk factors, characteristic clinical symptoms;
– examination – examination with valves to guide for the source of bleeding;
– ultrasound examination – exclusion of placenta previa, detection of hematoma. Not all cases of abruption are distinguishable sonographically;
– determining the state of the mother – number of erythrocytes, hemoglobin, hematocrit, fibrinogen test, coagulogram, fibrin degradation products;
– determination of blood group, Rh-typing;
– determination of the condition of the fetus – nonstress test (late decelerations, impaired reactivity and variability are detected on the recording, which indicate fetal distress).

Differential diagnosis: It is made with:
– placenta previa – with it, the bleeding is painless, the uterus is calm, the condition of the fetus is good;
– premature birth;
– vasa previa – presenting vessels – presence of fetal vessels in the fetal membranes, which are in the path of the presenting part of the fetus;
– rupture of the uterus;
– pregnancy accompanied by another acute condition – acute appendicitis, acute pyelonephritis, etc.

Treatment:

The behavior of the premature detachment of the placenta is determined depending on the severity of the condition and the duration of the pregnancy:

– in the case of weak to stopping bleeding, an immature but healthy fetus, delivery is postponed and the therapy is aimed at suppressing uterine activity, correction of anemia and hypovolemia (blood substitutes, blood in the relevant indications, volume-replacement solutions), treatment of concomitant disease – hypertension, etc., increasing fetal lung maturity (corticosteroids). These measures should be applied against the background of daily monitoring of the condition of the mother and the fetus.

– in case of uncontrollable bleeding or suffering of the fetus, a caesarean section is performed.

– in the case of a mature fetus, delivery is carried out – vaginal birth or caesarean section, the method being chosen depending on the severity of the condition.

In case of Rh-incompatibility, prophylaxis is carried out.

Prevention: The prevention of premature detachment of the placenta consists in reducing the risk by combating the predisposing factors:
– stopping smoking and alcohol consumption during pregnancy;
– avoiding activities that pose a risk of injury;
– treatment and monitoring of hypertension in pregnant women;
– follow-up of women with previous episodes of placental abruption, etc.