11/5- Complications of Late Pregnancy Flashcards
What are the 4 common complications of late pregnancy?
- Hypertensive disorders of pregnancy
- Preterm labor
- Fetal death/stillbirth
- Amniotic fluid abnormalities
Case 1)
- Mrs. Williams presents to your office at 32 weeks gestation for a routine prenatal visit. Her pregnancy has been uncomplicated so far.
- Today she complains of ankle swelling and a mild headache. Your nurse reports the patient’s blood pressure as 155/92.
- Urinalysis reveals 2+ proteinuria.
- Should you send the patient home or to the hospital?
To the hospital!
- There are many hypertensive disorders in pregnancy to think about
How does blood pressure change in pregnancy?
- At the beginning, it goes down a little
- In 3rd TM, it begins to rise
What are some hypertensive disorders that may be present in pregnancy?
- Chronic hypertension
- Preeclampsia/eclampsia
- Gestational hypertension
Define: chronic hypertension
- Present before conception
- Dx before 20 wk, or persists > 6 wk postpartum
Define: preeclampsia/eclampsia
Hypertension appearing after 20 wk gestation in association with proteinuria
Define: gestational hypertension
Hypertension appearing after 20 wk with no other evidence of preeclampsia (e.g. preeclampsia without the signs)
What is the epidemiology of preeclampsia?
- Prevalence
- More common in what populations/conditions
5-6% of pregnant pts
More common in:
- Maternal age < 20 or > 35
- African-Americans
- Nulliparas (never given birth before)
- Diabetes
- Obesity
- Systemic Lupus Erythematosus
- Multiple gestations
What are the diagnostic criteria for preeclampsia?
Hypertensive criteria
- Systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg
- On 2 occasions at least 4 hours apart
- After 20 weeks pregnant with previously normal blood pressure
OR
- Systolic blood pressure ≥ 160 mm Hg or diastolic blood pressure ≥ 110 mm Hg
PLUS Protein/symptomatic criteria
- Proteinuria > 300 mg/day (protein/creatinine ratio 0.3, urine dipstick +1 if no other method available)
OR
- Thrombocytopenia (Platelets < 100,000/microliter)
- Renal insufficiency (Cr >1.1, or doubling of serum cr)
- Impaired liver function (transaminases 2x normal)
- Pulmonary edema
- Cerebral or visual symptoms
What are the diagnostic criteria for preeclampsia with severe features?
- Systolic bp >160 mm Hg or diastolic bp >110 mm Hg on two occasions at least 4 hours apart
- Thrombocytopenia (Platelets under 100,000/microliter)
- Impaired liver function (transaminases twice normal)
- Severe persistent right upper quadrant or epigastric pain unresponsive to medication and not accounted for by other diagnosis
- Renal insufficiency (Cr >1.1, or doubling of serum creatinine in absence of other renal disease)
- Pulmonary edema
- Cerebral or visual symptoms
Describe the pathogenesis of preeclampsia
- Endothelial cell injury
- “Rejection” phenomenon (insufficient blocking antibodies)
- Abnormal placentation (incomplete invasion of trophoblast as placenta implants in uterus)
- Imbalance between thromboxane and prostacyclin
- Dietary factors
- Genetic factors
T/F: Preeclampsia is a multisystem disorder
True
What systems are affected in preeclampsia? How?
- CNS: arteriolar thrombosis, microinfarcts, petechial hemorrhages
- Pulmonary: pulmonary edema, ARDS
- Cardiovascular: depleted intravascular volume
- Liver: hepatocellular damage, hemorrhage, rupture
- Renal: decreased GFR, swollen and leaky glomerular capillaries, acute tubular necrosis
- Hematologic: low platelets, hemolytic anemia, DIC, HELLP
- Placental: poor intervillous blood flow, infarctions, IUGR
What is the prevalence of eclampsia?
- Occurs when
- Occurs in 0.2-0.5% of pregnancies
- Approximately 75% occur antepartum
What are the symptoms of eclampsia?
- Cause
- Etiology
- Tonic-clonic (grand mal) seizure activity
- Poor correlation between severity of HTN and occurrence of seizures
- Precise etiology of seizures is unknown (perhaps vasospasm)
What is shown here?
MRI findings with posterior reversible encephalopathy
How is preeclapmsia managed?
- Delivery is the only cure (think it has to do with placenta; got to get it out of there)
- Control hypertension:
- Hydralazine
- Labetolol
- Nifedipine
- Prevent seizures:
- Parenteral magnesium sulfate
- Optimize fetal outcome
Case 2)
- C.N. is a 23 year old G1 at 30 weeks gestation, and presents to your office complaining of lower abdominal pain and pelvic pressure.
- She is currently unemployed and is “stressed out” over financial issues. She is found to be having contractions every 4 minutes, and her cervix is partially dilated.
- Appropriate management includes admission to L/D and what additional measures?
____ is the #1 killer of neonates?
- Prevalence?
Prematurity is the #1 killer of neonates
- Difficult to detect and treat
- Multiple etiologies
- Affects ~10% of US pregnancies
The preterm birth rate is _______ (increasing/decreasing)? Why?
Preterm birth rate is increasing
- Multiple gestation rate is increasing
- Increased obstetric interventions (to prevent fetal death)
- Increased use of US-dating of pregnancies
What is the mortality rate with prematurity?
- Pretty much 100% before 24 wks
What are risk factors for high mortality with prematurity?
- Low gestational age
- Low birth weight
- Male
- No steroids
What is the neurologic morbidity of prematurity? (table)
- At 22 wks, none born live were alive at 6 mo
- At 24 wks, 56% were still alive at 6 mo but only 21% did not have severe brain abnormalities
- At 25 wks, 79% were alive at 6 mo and 72% did not have severe brain abnormalities (pic 494)
What is a big risk with prematurity?
- Risk factors?
Intraventricular hemorrhage
- Higher risk with lower infant weight
(50% if under 1kg but only 2% if > 2 kg)
How is preterm labor diagnosed/defined?
Painful uterine contractions with progressive cervical change at gestational age between 20 weeks and 36+6 weeks.
What are risk factors for preterm labor?
- Maternal
- Genetic
Maternal
- Low maternal weight gain
- Low socioeconomic status
- Substance abuse
- Young maternal age
- Psychologic stress
- Previous preterm labor
Genetic
- Collagen defects
- Uterine anomalies
T/F: most cases of preterm labor are of unknown etiology
True
What is the role of infection in preterm labor?
In the decidua and/or amnion:
- Bacteria products may activate monocytes to produce IL-1, IL-6, and TNF
- These cause release of arachidonic acid (platelet activating factors)
- Release of PGE2 and F2a
- Results in myometrium and uterine contractions
What is PROM?
- Describe the process
- How to manage
Premature Rupture of Membranes
- Loss of mechanical barrier to infection
- Release of prostaglandins secondary to inflammatory change
- Majority will deliver within 48 hours of PROM
- Management dependent on suspicion of intra-amniotic infection
What are complications of PROM?
- Fetal
- Maternal
Fetal
- Prematurity
- Pulmonary hypoplasia
- Infectious complications
- Structural deformities
Maternal
- Uterine infection
- Sepsis
How to manage preterm labor?
- Admission to L/D
- IV hydration/urinalysis
- Tocolytic agents
- Maternal corticosteroids to induce fetal lung maturity
- Antibiotics if delivery likely or with PPROM
Describe the effects of giving the mother corticosteroids to induce fetal lung maturity
- How long does this take
- Corticosteroids enhance surfactant production by type 2 alveolar cells
- Increase neonatal lung compliance
- Decreased alveolar protein leakage
- Stabilization of cellular architecture
- REQUIRES 48 HOURS FOR OPTIMAL EFFECT
What are tocolytic agents?
- Beta mimetics
- Magnesium sulfate
- CCBs
- Prostaglandin synthetase inhibitors
What are the mechanisms of action/details of use for the following tocolytic agents?
- Beta mimetics
- Magnesium sulfate
- CCBs
- Prostaglandin synthetase inhibitors
- Beta mimetics: B2 recep agonists cause uterine relaxation (turbuteline)
- Not recommended for long-term/maintenance use
- Magnesium sulfate: unknown action; presumed interference with Ca role in contractile apparatus
- CCBs: block cellular entry of Ca, reducing contractility
- Prostaglandin synthetase inhibitors (indosin)
- Not used after 32 wks; may cause premature closure of ductus arteriosus in the heart
What are adverse side effects of the following tocolytic agents?
- Beta mimetics
- Magnesium sulfate
- CCBs
- Prostaglandin synthetase inhibitors
- Beta mimetics: tachycardia, hypotension, nausea/vomiting, hyperglycemia, hypokalemia
- Magnesium sulfate: flushing, N/V, headache, weakness, diplopia, pulmonary edema, chest pain, hypotension, respiratory depression
- CCBs: hypotension, tachycardia, headache, flushing, dizziness
- Prostaglandin synthetase inhibitors: GI upset, coagulation disturbances, renal failure
- Fetal: renal dysfunction, oligohydramnios, premature closure of ductus arteriosus
Case 3)
- A.S. is a 34 year old at 29 weeks gestation with her 3rd pregnancy. She has gestational diabetes and chronic hypertension.
- During her office visit, she reports decreased fetal activity, and has felt none since this morning.
- Ultrasound evaluation confirms fetal demise.
- What is the likely etiology in this case?
Risk factors of stillbirth include:
- Gestational diabetes
- Chronic hypertension
What is the definition of a stillbirth?
- How many are for unknown reasons
Antepartum or intrapartum death of fetus > 500g
- Determination of etiology requires rigorous investigation
- Unexplained in 25-30% of cases (kind of good, because less risk of recurrence in later pregnancies)
What are fetal causes of fetal death?
- Chromosomal abnormalities
- Other structural anomalies
- Non-immune hydrops
- Infection (think TORCH infections; Toxo, Parvo, CMV, Syphilis)
What are placental causes of fetal death?
- Abruption
- Fetal-maternal hemorrhage (if blood types don’t match)
- Cord accident (strangulation or knot)
- Placental insufficiency
- Intrapartum asphyxia
- Twin transfusion syndrome
- Chorioamnionitis
What are maternal causes of fetal death?
- Antiphospholipid antibodies
- Diabetes
- Hypertension
- Trauma
- Sepsis
- Uterine rupture
- Postdates pregnancy
How is a stillbirth managed?
- Delivery by usual means
- Autopsy and other investigation
- Allow for grieving
- Follow-up visit (high risk for post-partum depression)
Where should amniotic fluid be sampled?
All 4 quadrants
What are some amniotic fluid abnormalities?
Hydramnios (polyhydramnios)
- AFI > 90th%ile
Oligohydramnios
- AFI < 10th%ile
- Max vertical pocket < 2 cm
What are causes of polyhadramnios?
Excessive production:
- Maternal diabetes
- Twins Impaired swallowing
- Neurologic disorders GI obstruction
- Intestinal atresia
What are causes of oligohydramnios?
- Impaired production:
- Uteroplacental insufficiency
- Renal dysplasias
- Fetal renal obstruction
- Leaking amniotic membranes
