Postpartum Hemorrhage - Causes and Symptoms

Definition

Postpartum hemorrhage is a very dangerous complication, which can occur during or after the last stage of birth (also called secondary or third stage of labor).

In women, excessive bleeding may have more or less serious results. The consequences of this massive loss can involve palpitations, dizziness, weakness, sweating, pallor and signs of hypovolaemia, such as low blood pressure, oliguria and tachycardia. If left untreated, hemodynamic instability could also lead to the death of the patient.

Specifically, postpartum hemorrhage is defined as:

Blood loss equal to or greater than 500 ml (considered serious if it exceeds 1000 ml) after a vaginal birth (during or immediately after the third stage of labor, in which the expulsion of the placenta and fetal appendages occurs);
Blood loss equal to or greater than 1000 ml in case of caesarean section .

Postpartum hemorrhage can be precocious (or acute) when it occurs within 24 hours of the child's birth or, less often, late (or secondary) when it occurs from one day to the 12th week after birth.

Postpartum hemorrhage may depend on various conditions, which, for the most part, are avoidable.

The most common cause is uterine atony (90% of the cases), which can be favored by an excessive activity of the organ, secondary to prolonged labor (over 12 hours), or to a too rapid birth (ex. emergency cesarean section or induced delivery) or dystocic.

Other factors that can predispose to this problem include uterine overdistension (due to a multiple pregnancy, a polydramnios or a large fetus for gestational age), high multiparity (birth of? 5 viable fetuses), the use of myorelaxant anesthetics and corioamnionite.

Postpartum hemorrhage can also be caused by cervical and / or perineum-vaginal lacerations, uterine rupture and retention of placental material (placenta accreta). Other causes include the extension of an episiotomy, the reversal of the uterus (a rare medical emergency in which the uterine body topples outwards and protrudes into the vagina or beyond the introit) and the incomplete involution of the placental insertion (which usually occurs early, but can also occur up to 1 month after birth).

A previous puerperal hemorrhage, uterine fibroids, retained or previous placenta, pre-eclampsia, obesity and maternal coagulopathies can contribute to postpartum blood loss. Predisposing conditions should be identified before birth and, when possible, corrected.

Treatment depends on the etiology of the bleeding. To reduce blood loss and uterine contractions after expelling the placenta, administration of oxytocin (intravenously or intramuscularly) or other urotonics (eg prostaglandins or methylergonovans) may be indicated.

The volume must be restored with 0.9% saline intravenously, sometimes associated with erythrocyte concentrates. In the presence of post-partum hemorrhage, genital lacerations must be repaired and any placental tissues retained must be removed. Sometimes, bleeding can be stopped by uterine tamponade or Bakri balloon placement until hemostasis is reached. In some cases, catheter drainage of the bladder can reduce uterine atony. On the contrary, uterine rupture requires surgical repair.

In any case, the magnitude of vaginal bleeding should be monitored for 1 hour after completion of the third stage of labor.