Risk factors for placental abruption

- Pre-eclampsia

- Chronic (pre-existing) hypertension

- Abruption of the placenta in previous births

-Hereditary and acquired hypercoagulability (Leiden's mutation, hyperhomocystinemia, protein deficiency C, protein S, antithrombin III, prothrombin mutation G20210A, hypo- and

dysfibrinogenemia, antiphospholipid syndrome).

- Diabetic angiopathy.

- Leiomyoma

- Age over 35 years old

- Chorionamnionitis

- Long anhydrous period (more than 24 hours)

- Low socioeconomic status

- Drug use, smoking

- Injury

- Sudden decompression (amniocentesis)

Clinical Features

Leading symptoms of placental abruption are: pain in the area of detachment of the placenta, hypertonicity of the uterus, fetal distress, bleeding (external, or signs of internal bleeding). Other clinical symptoms of premature separation of the placenta are dependant on severety of detachment and intensity of blood loss: alteration of the uterine shape, size, consistency.

In severe cases the woman complains of strong and persistant abdominal pain; the skin and mucosa are pale; the pulse is soft (pulsus mollis) and accelerated; the arterial blood pressure falls. General symptoms of internal bleeding may appear (ear noise, dizziness, etc. ), though external bleeding might be insignificant or even absent.

The progressing retroplacental hematoma increases the intrauterine pressure and causes excessive distension of the uterine wall. The uterus grows in size, its consistency becomes firm (may be as hard as wood), and the shape becomes ovoid or irregular. In total placental separation the uterus may become asymmetrical because of protrusion of its wall at the site of hematoma. The palpation of the uterus is very painful. Small fetal parts become impalpable because of the excessive strain of the uterine muscles; the fetal heart tones become irregular or discontinue; the fetus movements are absent. In a strong acute detachment of the placenta, sharp, knife-like pains appear, pains are constant, throughout the abdomen. Feelings arise that " something has torn in the abdomen”, complaints of a sharp " burning" in the area of separation appear. Pain can be irradiated to the hip, pubis, to the lower back.

Bleeding is often only internal, when the detachment occurs at the center of the placental area; a retrocolar hematoma. External bleeding occurs with placental abruption to edge. The blood flowing from the genital tract can be of different colors. If bleeding started immediately after detachment or blood was required pass a small distance from the peeling lower pole of the placenta to the vagina, it has a scarlet color. If after the detachment has passed for a while, the blood becomes dark, clots appear in it. With an abruption of 1/4 of the placenta and more, the mother shows signs of anemia and hemodynamic disorders. She complains of dizziness, weakness, a brief loss of consciousness is possible, a picture of shock develops due to rivovolemia and coagulopathy. The severity of the clinical picture depends on the variant of placental abruption.

Typical complications, particularly in case of development of placental abruption against the background of preeclampsia, include coagulopathy with disseminated intravascular coagulation, acute renal failure, and utero-placental apoplexy (Couvelaire uterus). Couvelaire uterus is dangerous by the absence of the possibility of contraction of the myometrium after delivery, the possibility of developing hemorrhagic and septic complications, up to the death of the mother after childbirth.

In mild degree the general condition of the patient is not changed. Pulse rate, blood pressure are normal, fetal heart sounds are not altered. Clinical signs are not so marked, and the diagnosis may be confused. One should pay attention to the local pain in the uterus, increased uterine tone, symptoms of fetal distress, etc. Pain occurs due to stretching of the uterine wall and irritation of the serous coat of the uterus with hematoma, formed at the site of placental abruption. The pain may be weak or more intense, first it is local, and then spreads throughout the abdomen.

The placental abruption (mild degree) may be diagnosed unexpectedly with transabdominal ultrasound (TAUS). In suach a case one should make repetitive sonography to evaluate retroplacental hematoma, if any, and its changes in dinamical sonographic observations (increase in size or not).

The fetus may show increased motor activity, or, conversely, become less active, then a woman ceases to feel fetus kicks.

If the woman is in labor, the fetal membranes are very tense both during the contractions and in the pauses. Pain in this case is not disappear in between contractions, and uterus may be not relaxed.

The separated placenta is delivered immediately after the fetus. Large amounts of liquid blood and clots are discharged together with the placenta. The overdistended uterus shrinks slowly and the bleeding therefore often continues during the first hours postpartum due to uterine atony and coagulopathy.

Management