Bleeding In Pregnancy Flashcards
Etiologies of Pregnancy Bleeding First Trimester
- Miscarriage (threatened, inevitable, incomplete, complete)
- Ectopic pregnancy
- Implantation bleeding
- Vaginal, cervical, uterine causes
- Gestational trophoblastic disease
Etiologies of Pregnancy Bleeding Second and Third Trimester
- Placenta previa
- Abruptio placenta
- Labor or cervical dilation
- Uterine rupture
Epidemiology
- Common antepartum complication
- Occurs in 20-40% of women in the first trimester of pregnancy
- Outcomes vary.
- Bleeding is less common in the second and third trimester
- Potentially more troublesome
- The fetus is likely viable.
- A common cutoff for viability (ability to survive outside the uterus) =
- 24 weeks gestational age
- 500g
Implantation Bleeding
- Implantation bleeding is light, physiologic bleeding that occurs 7-10 days after ovulation and reflects implantation of the fertilized egg into the uterus.
- It is often mistaken for menses, and is not experienced by all women.
- Implantation bleeding is not worrisome in and of itself, and workup and treatment are usually deferred.
Vaginal, cervical, uterine and other causes of bleeding
- It is important to verify the source of bleeding in any patient.
- Lacerations to the external genitalia, vagina, or cervix may cause bleeding.
- Cervical or vaginal polyps may bleed, and the cervical ectropion is frequently friable during pregnancy.
- Light postcoital bleeding is common.
- Other causes include infection and trauma.
- Hemorrhoids or urinary infections may also present with bleeding.
- Treatment varies with etiology.
Spontaneous Abortion (MIscarriage)
- SAB is subdivided into clinical categories
- Threatened abortion
-+ bleeding, cervical os closed
•Inevitable abortion
-+ bleeding , cervical os dilated
•Incomplete abortion
-some products of conception have passed
•Completed abortion
- all products of conception have passed
- cervical os is again closed
- [] of clinically recognized pregnancies under 20 week gestation end in spontaneous abortion
- [] weeks of pregnancy
- Less than [] loss rate after a fetal heartbeat is seen
- 8-20% of clinically recognized pregnancies under 20 week gestation end in spontaneous abortion
- 80% < 12 weeks of pregnancy
- Less than 5% loss rate after a fetal heartbeat is seen
- [] the gestational age at SAB = Higher the incidence of abnormal fetal karyotype.
- Maternal genetic abnormalities may lead to SAB
- []
- []
- []
•Etiology of SAB in healthy women often unclear.
- Earlier the gestational age at SAB = Higher the incidence of abnormal fetal karyotype.
- Maternal genetic abnormalities may lead to SAB
- Microdeletions
- Point mutations
- Turner’s Syndrome (45 XO)
•Etiology of SAB in healthy women often unclear.
Risk Factors for SAB
•Advancing maternal age = #1 in healthy women
-Up to 20% of women at age 35 undergo SAB.
•Previous SAB
- Up to 20% after a prior SAB
- 28% after two consecutive SAB
- 43% after three or more consecutive SAB
- Smoking (>10 cigarettes daily = RR 3)
- Alcohol consumption (moderate to high)
- Cocaine use
- Increasing gravidity
- Short interpregnancy interval
- Maternal endocrinopathies
- Diabetes
- Thyroid disorders
•Maternal infection
- Listeria monocytogenes
- Toxoplasma gondii
- Parvovirus B19
- Rubella
- Herpes simplex
- Cytomegalovirus
•Anatomic disorders
- Congenital (bicornuate uterus)
- Acquired (uterine fibroids)
•Hypercoagulable states
-Inherited or acquired thrombophilia
•Immune diseases
- Lupus
- Antiphospholipid syndrome
SAB Treatment
- Treatment varies
- <12 weeks gestational age, common for all products of conception to pass spontaneously
- 12 weeks, less common for complete passage of tissue
-significant amounts of placental tissue may be retained
•Need to evacuate uterus
- dilation and evacuation
- induction of labor
Ectopic Pregnancy Definition
- Any pregnancy occurring outside of the uterine cavity.
- 2% of pregnancies are ectopic.
- Implantation site varies
- 97% fallopian tube
- Abdomen
- Cervix
- Ovary
- Uterine cornua
Ectopic Pregnancy Risk Factors
•Previous ectopic is the major risk
- 15% recurrence after 1 ectopic pregnancy
- 30% recurrence after 2
- STD & PID
- Endometriosis
- Previous tubal surgery
- 10% of ectopic
- Assisted reproductive techniques.
- Increased age
- Smoking
- No risk factors present in 50% of ectopics
Ectopic Pregnancy Presentation
•Presentation:
- Abdominal pain
- Bleeding
- Report an early pregnancy (usually <14 wks)
•Ultrasound may confirm an ectopic gestation. Diagnosis = ectopic, if
- Do not see intrauterine pregnancy
- bhCG level appropriately elevated
Ectopic Pregnancy Treatment
- Treatment: surgical or conservative
- Surgical = removal of the ectopic tissue
- Conservative = methotrexate.
-Methotrexate is a chemotherapeutic agent
*Folic acid antagonist
*Administered as 1 or 2 IM injections
*Dosage of 50mg/m2.
*Doses are a fraction of chemotherapeutic tx
Cervical DIlation
- Cervix well vascularized during pregnancy
- Change in the cervix will cause the friable blood vessels to bleed
- Occurs in a number of settings
- Labor
- Uterine contractions accompanied by cervical dilation
- Cervical insufficiency (Not so good)
*Dilation outside the setting of labor
Placenta Previa
Placenta Previa Presentation
- Present as painless vaginal bleeding after 20 weeks of pregnancy
- Suspicion should be high in any woman with bleeding in the second or third trimester
- Avoid digital cervical exam if can not confirm normal placentation — > BLEEDING
Placenta Previa Pathologic Mechanisms
•Placenta migrates away from the cervical os occurs as pregnancy progresses.
- Development of lower uterine segment relocates lower edge of placenta away from the internal os.
- Early ultrasound commonly shows previa
•Endometrial scarring in the upper uterine segment of the uterus
-promotes trophoblastic growth into the unscarred lower uterine segment
- Deficient uteroplacental oxygen or nutrient delivery
- Placental surface area expands(over the os) to compensate
Complete Previa
- placenta completely covers the internal os
- Up to 30% of previas
Partial Previa
•placenta partially covers os.
Marginal Previa
- Placental edges adjacent to the os
- as cervix dilates, placenta may cover os.
Low lying Placenta
- placenta within 2-3 cmof os.
- Lower risk of bleeding, but still a concern.
Placenta Previa Risks
- Correspond with pathophysiologic mechanism.
- Early gestational age
- Risk factors associated with endometrial scarring -Prior cesarean deliveries
- Increased maternal age
- Previous uterine surgeries curettage
- Multiple gestation
- Smoking
- Poor nutrition
Placenta Previa Treatment
•Treatment varies according to
- Severity of bleeding
- Status of fetus and mother
- Gestational age
- Minimal spotting –> managed expectantly *
- Hemorrhaging previa –> delivery at any gestational age.
- Delivery mode:
- Cesarean delivery
- Low-lying placenta may be offered vaginal delivery *
* = pending clinical consideration
Placental Abruption
•Complicates about 1 in 100 births
-peak incidence 24 - 26 weeks
- “Decidual hemorrhage leading to the premature separation of the placenta prior to delivery of the fetus”
- Vaginal bleeding with abdominal pain.
- Sustained uterine contraction
- Nonreassuring fetal heart rate patterns
Placental Abruption Pathologic Mechanism
- Rupture of maternal vessels in decidua basalis at interface with anchoring villi in placenta –>
- accumulating blood splits the decidua from attachment in uterus –>
- hematoma
- May be small and self-limited
- May continue to dissect placental-decidual interface
- Leads to complete or near complete placental separation.
- Detached portion of the placenta unable to exchange gases and nutrients –>
- Fetal compromise
Placental Abruption Risk Factors
- Acute mechanical force
- Abdominal trauma
- Rapid uterine decompression
- Preterm premature rupture of membranes
-(2-5% risk)
- Hypertension (5-fold risk)
- Pre-eclampsia
- Smoking (5-fold risk)
- Cocaine use (10% risk)
- Previous bleeding in the pregnancy
Uterine Rupture
•Detachment of the placenta – > Compromised blood flow to the fetus –> Fetal asphyxia and acidemia –> Fetal death.
*Significant hemorrhage
*Maternal status compromised
*Massive transfusions may be needed to avoid maternal death.
Uterine Rupture Risk Factors
•Previous uterine surgery
- Transfundal uterine incisions
- Previous cesarean deliveries
*Low-transverse uterine incision (most common uterine incision in term cesarean deliveries)
-1-2% risk of rupture
*1 or 2 prior low transverse incisions
- Permitted to labor and attempt a trial at vaginal delivery
- Rupture risk may exceed 3%.
*A previous uterine incision other than low transverse (includes vertical and fundal incisions)
- Rupture risk approaches 4%.
- Repeat cesarean delivery recommended
Uterine Rupture Treatment
- Immediate delivery
- ontrol hemorrhage
- Women have higher risk of:
- Immediate hysterectomy
- ICU admission
