Ordinarily the myometrial fibers of the uterus contract and retract causing
kinking of the blood vessels at the placental site. The kinked vessels
cease providing blood to the placental site and bleeding is controlled.
Uterine atony is responsible for 80 percent to 90 percent of postpartum
hemorrhage cases. This failure may be due to uterine dysfunction,
anesthesia, ineffective first and second stage contractions, overdistention
of the uterus, exhaustion due to a long labor, multiparity, myomas and
operative deliveries which traumatize the uterus, and mismanagement of the
placental stage of labor. Most of these causes can be anticipated and the
appropriate management taken to lessen the risks of a hemorrhage.
Third stage hemorrhage can be caused by overzealousness on the part of the
attendant to get the placenta out. Massaging a uterus with an as-yet
unseparated placenta attached may cause a partial separation with the
resultant bleeding by vessels that still have maternal blood coursing
through them. Pulling on the cord to remove a still-adhered placenta may
accomplish the same effect. -Yvonne Lapp Cryns, Midwifery Today Issue 34,
excerpted
Reprinted from Midwifery Today E-News (Vol 2 Issue 20 May 19, 2000)
To subscribe to the E-News write: enews@midwiferytoday.com
For all other matters contact Midwifery Today:
PO Box 2672-940, Eugene OR 97402
541-344-7438, midwifery@aol.com, Midwifery Today
|
|