Early amniotomy has long been championed in the manage ment of placental abruption. his ostensibly achieves better spi ral artery compression to diminish implantation site bleeding and reduce thromboplastin infusion into the maternal vascular system. Although evidence supporting this theY is lacking, membrane ruprure may hasten delivery. However, if the fetus is small, the intact sac may be more eicient in promoting cervical dilation. If rhythmic uterine contractions are not superimposed on baseline hypertonus, then oxytocin is given in standard doses. No data indicate that oxytocin augments thromboplas tin escape into the maternal circulation to worsen coagulopathy (Clark, 1995; Pritchard, 1967). In light of hypertonus associ ated with abruption, misoprostol may be a less favored induc tion agent due to its association with uterine tachysystole.
In the past, some had set arbitrary time limits to permit vaginal delivery. Instead, experiences illustrate that maternal outcome depends on the diligence with which adequate luid and blood replacement therapy are pursued rather than on the interval to delivery. Observations from Parkland Hospital described by Pritchard and Brekken (1967) are similar to those from the University of Virginia reported by Brame and associates (1968). Specifically, women with severe abruption who were transfused during 18 hours or more before delivery had similar outcomes to those in whom delivery was accomplished sooner.
Expectant Management with a Preterm Fetus
If possible, delaying delivery may benefit an immature fetus. Bond and colleagues (1989) expectantly managed 43 women with placental abruption before 35 weeks' gestation, and 31 of them were given tocolytic therapy. he mean interval-todelivery for all 43 was approximately 12 days. Cesarean delivery was performed in 75 percent, and there were no stillbirths. As discussed earlier, women with a very early abruption may develop chronic abruption-oligohydramnios sequence. In one report, Elliott and coworkers (1998) described four women with an abruption at a mean gestational age of 20 weeks who developed oligohydramnios and delivered at an average gestational age of 28 weeks. In a description of 256 women with an abruption at <28 weeks' gestation, Sabourin and colleagues (2012) reported that a mean of 1.6 weeks was gained. Of the group, 65 percent were delivered <29 weeks, and half of all women underwent emergent cesarean delivery.
Unfortunately, even continuous fetal heart rate monitoring does not guarantee universally good outcomes. For example, a normal tracing may precede sudden further separation with instant fetal compromise. In some of these, if the separation is suicient, the fetus will die before it can be delivered. Tocolysis is advocated by some for suspected abruption if the fetus does not display compromise. Some investigators have observed that tocolysis improved outcomes in a highly selected cohort of women with preterm pregnancies (Bond, 1989; Combs, 1992; Sholl, 1987). In another study, Towers and coworkers (1999) administered magnesium sulfate, terbutaline, or both to 95 of 131 women with abruption diagnosed before 36 weeks. The perinatal mortality rate was 5 percent in both groups with or without tocolysis. Similar results were reported from a randomized trial (Colon, 2016). We are of the opinion that suspected placental abruption contraindicates use of tocolytic agents.
The Latin previa means going bore-and in this sense, the placenta goes before the fetus into the birth canal. In obstetrics, placenta previa describes a placenta that is implanted somewhere in the lower uterine segment, either over or very near the internal cervical os. Because these anatomical relationships cannot always be precisely deined, and because they frequently change across pregnancy, terminology can sometimes be confusing.