1229 Exam 5: Placenta Previa and Abruptio Flashcards
Life support system for the unborn baby
Supplies oxygen and nutrients to the fetus
Removes wastes
Produces hormones
Protects from infections/harmful substances
Placenta
Placenta has implanted in the lower uterine segment near or over the internal cervical os
Occurs in about 1 out of every 500 births or 0.5%
3 Types:
-Complete
-Partial
-Marginal
Placenta Previa
When placenta completely covers the internal os
Complete Placenta Previa
Incomplete coverage of the internal os by the placenta
Partial Placenta Previa
Placenta is near the edge of the internal os (2-3 cm from internal os)
Also called low-lying placenta in the second trimester
-Because it can move upward as the pregnancy progresses
Marginal Placenta Previa
Cause of Placenta Previa
No actual cause known
Risk Factors for Placenta Previa
Endometrial scarring from -Previous Placenta Previa -Previous C-Section -Suction Curettage --From miscarriage or abortion -Multiple gestation -Multiparity Maternal age over 35 African or Asian ethnicity Smoking
Anytime vaginal bleeding occurs after 20 weeks of gestation
Bleeding often occurs as the lower uterine segment stretches and thins during the third trimester of pregnancy. This causes the area of the placenta over the cervix to bleed.
Bleeding is bright red
Previa should be suspected
Signs and Symptoms of Previa
Painless, bright red vaginal bleeding
VS may be normal
-Can loose 40% blood volume before S/S shock
-Clinical picture and decrease urine output are more accurate
Soft, relaxed non-tender uterus with normal tone
Fundal height usually greater than gestational age
-Low placenta hinders descent of presenting part
S/S continued
Leopold’s maneuvers may reveal breech or transverse position
-Manual manipulation to define fetal position
Most common symptoms:
sudden, painless, minimal to severe bright red vaginal bleeding during third trimester
How is Previa diagnosed?
Ultrasound can diagnose and pinpoint location of pre via
Transabdominal ultrasound
Transvaginal ultrasound
-Used with exact location cannot be seen with abd ultra
-BUT…only if no other option
Vaginal exams are avoided d/t risk of causing more bleeding
If vaginal exam must be done:
-Anticipate need for immediate cesarean birth
-Will usually do in a surgical suite set up for a c-section
-Hemorrhage can occur during the exam
Possible Complications for Previa
Premature Rupture of Membranes Preterm labor/birth Blood transfusion reactions Over-infusion of fluids Abdominal placental attachments Vasa previa -Umbilical Vessels below the presenting part C-section related complications -Surgery related trauma -Anesthesia complication
Complications continued
Postpartum hemorrhage Anemia Thrombophlebitis Infection Fetal risks: -Fetal death r/t preterm labor/birth -Malpresentation --Breech/transverse -Congenital anomalies -Small for gestational age --Poor placental exchange --Hypovolemia from blood loss and maternal anemia
Management of Previa
Depends -on the stage of pregnancy -on the severity of the bleeding -on the condition of baby and mother Cesarean section is usually recommended
Active Management
Admit to L&D Continuous fetal/uterine monitoring MOM -Carefully watch BP, HR, LOC, Output C-Section if term and bleeding -37 weeks Partial/Marginal Previa -With minimal bleeding -May attempt vaginal birth
Expectant Management
less than 36 weeks, not in labor, bleeding mild or stopped
Admit to hospital Continued fetal/uterine monitor - BPP & NST Bed rest with BRP Monitor bleeding -# of pads/weigh pads -No vag or rectal exams Ultrasound q 2-3 days Monitor labs -H&H, coagulation factors IV infusion or saline lock -Blood and blood products Antepartum steriods -Betamethasone (< 34 weeks)
Treatment for previa
Home Care
- Must be stable
- No evidence of active bleeding
- Must be able to return to hospital immediately for active bleeding
- Close supervision by family and friends
- Taught to assess fetal and uterine actively and bleeding
- Must avoid intercourse, douching, and enemas
- Limit activity according to physician
- Keep all appointments for fetal testing/lab assess/prenatal care
- Perinatal home care nurse will visit
treatment continued…
Previa is always considered a potential emergency
-massive blood loss resulting in hypovolemic shock can occur rapidly
Possible continued hemorrhage after birth due to inability of the uterus to contract in that location
-Upper portion of uterus
Has interfacing muscle bundles around vessels to the placenta
Forms a “living ligature” to stop the bleeding after birth
This is absent in the lower part of the uterus
Prognosis for Previa
Probable outcome
-Very good if the condition is managed appropriately
Fetal Distress
-Not usually present unless a cord accident occurs
-Or blood loss heavy enough to cause maternal shock
-Or placenta abruptio
Other Types of Previas
Vasa Previa
Placenta accreta
Placenta increta and percreta
Umbilical vessels are not covered with Wharton’s jelly so they are fragile and cross the internal os below the presenting part
Teraring and hemmorrhage is frequently seen with ROM
Vasa Previa
Placenta implants too deeply into uterine wall
Placenta accreta
Placenta that imbeds itself even more deeply into uterine muscle
Or through the entire thickness of the uterus
Often extending into nearby structures such as the bladder
Placenta increta and percreta
The detachment of part of all the placenta detaches from the implantation site in the uterine wall, partially or almost completely after 20 weeks and before delivery
Mild cases:
-only cause a few problems
Severe cases:
-can deprive the fetus from oxygen and nutrients
-also cause bleeding in the mother
-endangers both mother and baby
Abruptio Placenta
