What is ICP - Risks

What is ICP?


Risks

Risks of Intrahepatic Cholestasis of Pregnancy (ICP)

Meconium staining

The first stool produced by a baby after birth is known as meconium. It is thick, sticky, and dark green in color. Sometimes, as a result of stress, the baby passes this stool before birth, which can contaminate the amniotic fluid, staining it a green color. If this fluid is inhaled during practice breathing, it can lead to respiratory issues after birth. Meconium staining is common in late pregnancy, however, in an uncomplicated pregnancy it is quite rare at 37 weeks. In an ICP pregnancy, it is common at 37 weeks, affecting 44-58% of women at this gestation. Discovery of meconium staining (e.g. in an amniocentesis) warrants immediate delivery during Intrahepatic Cholestasis of Pregnancy as it is highly associated with the risk of stillbirth in these pregnancies.

Preterm labor and delivery

Preterm labor is very common during Intrahepatic Cholestasis of Pregnancy. This is due to the fact that the high levels of bile acids make uteruses more sensitive to the hormone oxytocin. This is the hormone which is responsible for stimulating uterine contractions (it is also known by the brand name Pitocin, and is a hormone which is produced naturally in our bodies). Because of this increased sensitivity, it takes less of this natural hormone to create productive contractions. Preterm delivery occurs spontaneously (meaning not induced) in about 20-40% of ICP pregnancies. While it is considered a part of active management to induce early, delivering the baby too soon comes with considerable risks. If there are signs of preterm labor prior to scheduled induction, seek medical attention immediately.

Fetal distress

Fetal distress is characterized by changes in heart rhythms which may indicate that the baby is not coping well with the stresses of pregnancy. These rhythms can be measured by a test known as a Non-Stress Test (NST). Abnormal heart rhythms may include prolonged decelerations (low heart rates), prolonged accelerations (high heart rates), or rhythms with too little variability (not enough ups and downs). A doctor or technician can correctly interpret an NST.

Maternal hemorrhage

Older studies prior to active treatment of Intrahepatic Cholestasis of Pregnancy showed a high risk of maternal hemorrhage following delivery. This was speculated to be due to decreased vitamin K absorption, which is associated with cholestasis. Newer studies since the condition has been actively treated have not shown any increase in risk of hemorrhage. If vitamin K malabsorption is of concern (especially if pale stools or abnormal bruising is noted), the tests Prothrombin Time (PT) and Partial Thromboplastin Time (PTT) can be performed to check whether blood is clotting normally. If abnormalities are found, they can be corrected with oral vitamin K supplements.

Respiratory Distress Syndrome (RDS) and failure to establish breathing (fetal asphyxia)

ICP babies are at higher risk of respiratory issues at birth. These issues are considered a part of the disease process and are not necessarily due to the practice of early delivery, since they occur even when the lungs are known to be mature and they also occur in much higher rates than in non-ICP babies who are born at the same gestational age. One of the ways Intrahepatic Cholestasis of Pregnancy is known to cause respiratory issues is through a process known as bile acid pneumonia, wherein the bile acids in the amniotic fluid are breathed in through practice breaths and cause damage to the lungs.

Stillbirth (Intrauterine Fetal Demise)

Without active management the risk of stillbirth during an Intrahepatic Cholestasis of Pregnancy can be as high as 15%. However, with active management, including the medication Ursodeoxycholic Acid and early delivery (typically by 36-37 weeks gestation), the risk is thought to be about the same as an uncomplicated pregnancy, meaning less than 1%. The mechanisms that lead to stillbirth are not fully understood, and it is impossible to predict which pregnancies are at risk. While studies have found that higher bile acid levels appear to bring higher risk of certain complications such as respiratory distress and fetal distress, studies have not been able to identify the same relationship for stillbirth. Therefore, all ICP pregnancies are recommended to be delivered early. Research has identified several ways in which the disorder may potentially lead to stillbirth, including premature aging of the placenta, changes to the fetal heart induced by bile acids, and abnormal contraction of umbilical blood vessels.