Bleeding after midpregnancy is associated with several adverse outcomes. he Canadian Perinatal Network described 806 women with hemorrhage between 22 and 28 weeks' gestation (Sabourin, 2012). Placental abruption (32 percent), previa (21 percent), and cervical bleeding (6.6 percent) were the most frequent causes identified. In a third, no cause was found. Of all women, 44 percent were delivered before 29 weeks' gestation. In more than 68,000 women in Scotland, the incidence of antepartum hemorrhage after the irst trimester was 11 percent (Bhandari, 2014). hese women were at signiicantly higher risk for preterm birth, labor induction, and postpartum hemorrhage.
In most cases, the source of postpartum hemorrhage can and should be determined. Frequent causes are uterine atony with placental site bleeding, genital tract trauma, or both. Postpartum hemorrhage is usually obvious. Important exceptions are unrecognized intrauterine and intravaginal blood accumulation and uterine rupture with intraperitoneal or retroperitoneal bleeding. Another consideration is an expanding vulvar or vaginal hematoma (p. 764). Initial evaluation attempts to diferentiate uterine atony from genital tract lacerations. For this, risk factors are sought, the lower genital tract is examined, and uterine tone is assessed. Atony is identiied by a boggy, soft uterus during bimanual examination and by expression of clots and hemorrhage during uterine massage.
Persistent bleeding despite a firm, well-contracted uterus suggests that hemorrhage most likely is from lacerations. Bright red blood further suggests arterial bleeding. To conirm that lacerations are a source of bleeding, carful inspection of the vagina, cervix, and uterus is essential. Sometimes bleeding may be caused by both atony and trauma, especially after forceps or vacuum-assisted vaginal delivery. Examination is easier if conduction analgesia was given. If there are no lower genital tract lacerations and the uterus is contracted, yet supracervical bleeding persists, then manual exploration of the uterus is done to exclude a uterine tear (Kaplanoglu, 2016). his also is completed routinely after internal podalic version, breech extraction, or successful vaginal birth after cesarean.
Late pospartum hemorrhage describes bleeding after the irst 24 hours. Found in up to 1 percent of women, it may be serious and is discussed in Chapter 37 (American College of Obstetricians and Gynecologists, 2017 d).
As noted, visual estimates are notoriously inaccurate, especially with excessive bleeding. Instead of sudden massive hemorrhage, postpartum bleeding is frequently steady. If atony persists, bleeding may appear to be only moderate at any given instant but may continue until serious hypovolemia develops. Bleeding from an episiotomy or a vaginal laceration can also appear to be only minimal to moderate. But, constant seepage can lead to enormous blood loss relatively quickl)r . In some cases, ater placental separation, blood may not escape vaginally but instead may collect within the uterine cavity, which can become distended by 1000 mL or more of blood. In others, postpartum uterine massage is applied to a roll of abdominal fat mistaken for the uterus.