General Knowledge
What is the most common liver disease unique to pregnancy?
IHCP
What is the most common symptom?
Pruritus, worse in the evening, affecting palms and soles.
How is IHCP diagnosed?
Pruritus a/w elevated total serum bile acid levels, elevated aminotransferases, or both.
Of note, pruritus precedes lab findings, collect weekly.
Also, if you start tx, lab findings may not occur as they will normalize.
Name pathophysiology of disease.
Maternal bile acids cross the placenta. Transplacental gradients facilitate fetal clearance of bile acids in normal pregnancies, but are reversed in cholestatic pregnancies, which causes accumulation of bile acids in the fetus and amniotic fluid and carries significant risk for the fetus.
What are the two main management goals in IHCP?
1. Decrease maternal bothersome symptoms
2. Decrease fetal M&M
Incidence of IHCP in USA.
0.8
Fun fact: worldwide <1-27.6% (Araucanos Indians in Chile) and for unknown reasons, more common in the winter months in some countries (eg, Sweden, Finland, Chile).
Name other symptoms.
Right upper quadrant pain, nausea, poor appetite, sleep deprivation, or steatorrhea.
DDx: Name pre-pregnancy causes of pruritus.
- Atopic dermatitis
- Allergic/drug reaction
- Systemic disease (liver, renal, thyroid)
What are the fetal complications of IHCP?
- IUFD
- Meconium-stained fluid
- Preterm birth (iatrogenic or spontaneous)
- Neonatal respiratory distress syndrome
What is the preferred treatment for IHCP?
Ursodeoxycholic acid (300 mg 2-3 times per day, can titrate based on maternal sx not labs)
What is the etiology of IHCP?
Unknown. A combination of genetic susceptibility, hormonal influence, and environmental factors.
Name physical exam findings.
Typically, no rash but can patient can have excoriations. Jaundice (14-25%).
DDx: Name pre-pregnancy causes of hepatic impairment.
- Viral Hepatitis
- Autoimmune Hepatitis
- Primary biliary cirrhosis or primary sclerosing cholangitis
- Drug induced liver injury
- Biliary obstruction
- Venocclusive disease
What is severe IHCP defined as and what notable fetal effect is substantially increased?
40 and stillbirth
Stats:
<40 micromol/L: 0.13 %
40 to 99 micromol/L: 0.28 %
≥100 micromol/L: 3.44 %
What effect does ursodeoxycholic acid have on IHCP?
- Improves labs (so DO not change delivery plans)
- Decreases preterm birth
- No changes in IUFD
Name 4 risk factors for IHCP.
1. Personal (44% recurrence rate) or FH of IHCP
2. AMA
3. Multiple gestation
4. Chronic Hep C infection
*Patient with chronic liver disease/cirrhosis have a higher risk for IHCP.
Name the bile acids involved when obtaining labs.
Cholic and chenodeoxycholic acids.
DDx: Name pregnancy-specific causes of hepatic impairment.
- Acute fatty liver of pregnancy
- HELLP
- Hyperemesis gravidarum
Of note, IHCP a/w development of AFLP and PreE.
What is the pathophysiology of IUFD in IHCP?
Sudden development of a fetal arrhythmia or vasospasm of the placental chorionic surface vessels induced by high levels of bile acids.
1. Until diagnosis is made, need labs to be elevated before treatment with medications
2. During treatment, to monitor if BA are increasing requiring earlier delivery
3. Postpartum, if symptoms do not resolve
Name 5 reasons why estrogen is thought to play a major role in IHCP.
- Mainly in the second half of pregnancy when serum concentrations of estrogen reach peak levels
- More common in twin pregnancies, which are associated with higher levels of circulating estrogen
- Reported in early pregnancy after ovarian hyperstimulation (markedly high serum estrogen levels)
- Resolves in the days following delivery of the placenta, the major source of estrogen production second and third trimesters
- Occurs in individuals taking estrogen-progestin contraceptives
*Latter individuals who have IHCP, need to change to progesterone only contraceptives after birth.
Name other labs, ultrasound, and histopathology findings.
Labs:
- Elevated liver enzymes 60% (typically than 2x times upper limit)
- Elevated today and direct bilirubin (25%)
- Elevated GGT (30%)
US: no abnormalities
Liver bx: unnecessary but if done cholestasis without inflammation
DDx: Name pregnancy specific causes of pruritus.
- Pruritus gravidarum
- Atopic eruption of pregnancy
- Polymorphic eruption of pregnancy
- Pemphigoid gestationis
- Prurigo of pregnancy
- Pruritic folliculitis of pregnancy
What is the pathophysiology for SPONTANEOUS preterm birth that is seen in IHCP?
Bile acids appear to increase expression of myometrial oxytocin receptors.
Name antenatal monitoring and delivery timing per ACOG.
Delivery:
BA <100 36-39 wks
BA >100, at 36 wks