Lecture 9 Labor and birth complications Flashcards
(48 cards)
Placenta previa
- Implantation of the placenta in the lower uterine segment such that it completely or partially covers the cervix or is close enough to the cervix to cause bleeding when the cervix dilates or the lower uterine segment effaces.
- Unique features: Painless, bright red vaginal bleeding; fundal height greater than expected for gestational age; fetus is commonly transverse, breech or oblique with a high, non-engaged presenting part.
- Cesarean birth is preferable.
Complete placenta previa
Placenta previa in which the placenta totally covers the internal cervical os.
Marginal placenta previa
Placenta previa in which the edge of the placenta is seen on transvaginal ultrasound to be less than 2.5 cm or closer to the internal cervical os.
Low-lying placenta
- Placenta previa in which the exact relationship of the placenta to the internal cervical os has not been determined.
- Apparent placenta previa in the second trimester.
Placenta previa is commonly diagnosed using _
A transvaginal ultrasound.
The major maternal complication associated with placenta previa is _, and in some cases _ may be necessary.
Hemorrhage; a hysterectomy.
“Expectant management” refers to _
Observation and bed rest (“watchful waiting”).
For a patient with placenta previa experiencing signs of preterm labor, _ can be administered for tocolysis.
Magnesium sulfate.
Abruptio placentae
- The detachment of part or all of a normally implanted placenta from the uterus (premature separation of the placenta; placental abruption). Marked by painful, dark red vaginal bleeding.
- Difficult to diagnose - sometimes seen as a retroplacental mass on an ultrasound; hypofibrinogenemia and evidence of DIC support the diagnosis. Should be highly suspected in the woman who experiences a sudden onset of intense, usually localized, uterine pain, with or without vaginal bleeding.
- Vaginal birth is preferable.
Placental abruption - grade 2 moderate separation (20%-50%)
Absent to moderate vaginal bleeding, 1000-1500 mL total blood loss, painful, increased uterine tone, gestational or chronic hypertension commonly present. Abnormal FHR and pattern.
Placental abruption - grade 3 severe separation (>50%)
Absent to moderate vaginal bleeding, >1500 mL total blood loss, agonizing, unremitting uterine pain, tetanic, persistent uterine contractions with boardlike uterus, DIC frequently present, shock is common and may occur suddenly, gestational or chronic hypertension commonly present. Abnormal FHR and pattern. Fetal death can occur.
Couvelaire uterus
Associated with placental abruption; occurs when blood accumulates between the separated placenta and the uterine wall. The uterus appears purple or blue rather than its usual “bubblegum pink” color, and contractility is lost.
A positive Apt test result indicates _
Blood in the amniotic fluid.
Kleihauer-Betke (KB) test
May be ordered in cases of placental abruption; determines the presence of fetal-to-maternal bleeding. Does not diagnose placental abruption but is useful for purposes of guiding RhoGAM administration.
Fetal concerns related to placental abruption
- The two primary risks to the fetus are IUGR and preterm birth.
- Corticosteroids are given to accelerate fetal lung maturity.
Vasa previa
- Occurs when fetal vessels lie over the cervical os and are implanted into the fetal membranes rather than into the placenta.
- The umbilical vessels are not surrounded by Wharton jelly and have no supportive tissue. The umbilical blood vessels thus are at risk for laceration at any time, but laceration occurs most frequently during ROM.
Disseminated intravascular coagulation (DIC)
- A pathologic form of clotting that is diffuse and consumes large amounts of clotting factors, causing widespread external bleeding, internal bleeding, or both and clotting.
- Obstetric population - most often triggered by the release of large amounts of tissue thromboplastin, which occurs in placental abruption.
- Lab findings: Decreased platelets, presence of fibrin split products, prolonged PT and PTT.
In caring for the woman with DIC, which order should the nurse anticipate?
Administration of blood. [Primary medical management in all cases of DIC involves a correction of the underlying cause, volume replacement, blood component therapy, optimization of oxygenation and perfusion status, and continued reassessment of laboratory parameters.]
Preterm birth
Any birth that occurs before 37 0/7 weeks gestation.
Low birth weight
An infant born weighing 2500 g or less.
The most common cause of spontaneous preterm labor is _
Infection: Bacterial cervical or urinary tract infections; infection of the amniotic fluid, placenta, and membranes; periodontal disease.
Magnesium sulfate (neuroprotection)
- Administered for fetal neuroprotection against cerebral palsy in women anticipating preterm birth at less than 32 weeks of gestation.
- Also administered on a short-term basis (up to 48 hours) from 24 to 34 weeks in conjunction with betamethasone for lung maturity.
Major interventions for preterm labor
- Transfer of the mother before birth to a hospital equipped to care for her preterm infant.
- Giving antibiotics during labor to prevent neonatal group B streptococci infection.
- Administering glucocorticoids to prevent or reduce infant respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis.
- Administering magnesium sulfate to women giving birth before 32 weeks of gestation to reduce the incidence of cerebral palsy in their infants.
Tocolytic agents
Medications given to arrest labor after uterine contractions and cervical change have occurred. Rationale for use is to allow time for maternal transport and for corticosteroids to reach maximum benefit for the neonate.
- Magnesium sulfate.
- Terbutaline (Brethine), ritodrine - β₂-adrenergic agonists.
- Nifedipine (Procardia) - a calcium-channel blocker.
- Indomethacin (Indocin) - a NSAID.