Actress/singer Mandy Moore is pregnant with her second child, which is due this October. The This is Us co-star recently revealed that she will have an unmedicated birth with this child as she did with her first, a boy named Gus. She is unable to receive epidural anesthesia during delivery because she has immune thrombocytopenic purpura (ITP), an autoimmune disease that depletes platelets.
During her first pregnancy, her platelet count and she required weekly platelet count checks. The birth was difficult and required vacuum extraction, but mother and child did fine. Now Moore , "My platelets are too low for an epidural.... It was awful. But I can do it one more time. I can climb that mountain again."
On , Moore shared that "I am fine. I just have to continue to get my blood checked -- my platelet levels checked -- throughout pregnancy. They're low, but they've always been low. But I'm all good. Everything's good."
After finishing This is Us, which ended its 6-season run in May, Moore had planned to concentrate on her singing career and had started a North American tour to promote her In Real Life album. However, she recently cancelled the remainder of the tour, writing on : "When we booked these shows, I wasn't pregnant and although I truly thought I could power through, the way we are traveling (long hours on the bus and not getting proper rest) has caught up, taken its toll, and make it feel too challenging to proceed. I know that I have to put my family and my health (and the health of my baby) first and the best place for me to be right now is at home."
Immune Thrombocytopenic Purpura
ITP is an acquired thrombocytopenia caused by autoantibodies against platelet antigens. It is characterized by low platelet count, purpura and hemorrhagic episodes. Immunoglobulin G (IgG) autoantibodies cause sensitization of circulating platelets. These platelets are then removed by antigen-presenting cells such as macrophages, promonocytes and their precursors, found in the spleen, liver, lung, and bone marrow. The diagnosis is usually made by the exclusion of other causes of thrombocytopenia.
ITP can be acute or chronic, with the delineation between the two at about 6 months. Acute ITP occurs more commonly in children of both sexes and is the most common type of ITP. It is frequently preceded by a viral infection. Chronic ITP affects individuals 20-50 years old and women three times more often than men. Preceding viral infection is not typically present.
It is estimated that annual ITP incidence is approximately 1 to 6 per 100,000 adults worldwide. In the U.S., the prevalence is approximately 8 per 100,000 children and 12 per 100,000 adults.
Symptoms
Many patients with ITP are asymptomatic and otherwise appear healthy. However, ITP can cause bleeding that is difficult to stop. Bleeding may be internal, subcutaneous, or from a break in the skin.
Signs of bleeding may include:
- Petechiae
- Purpura
- Hematomas
- Nosebleeds or gingival bleeding
- Blood in urine or stool
- Heavy menstrual bleeding
- Extreme tiredness
Laboratory Findings
Laboratory findings may include:
- Low platelet count, usually <100,000 µmole/L. The greatest concern is for patients with platelet counts <20,000 µmole/L who are more likely to have clinically significant bleeding.
- Peripheral blood smear: the morphology of red blood cells and leukocytes is normal. Platelets can be normal in size, but there are varying numbers of large platelets as well.
- Bone marrow examination shows an increase in the number of megakaryocytes.
- Platelet Coombs test can identify antibodies that bind to the surface of platelets.
Treatment of ITP
For most children and adults, ITP is not a serious condition. Acute ITP in children often goes away on its own within a few weeks or months and does not return.
Chronic ITP varies from person to person and can last for many years. Even people who have serious types of chronic ITP can live for decades. Most people who have chronic ITP can stop treatment at some point and maintain a safe platelet count.
Treatment depends upon a patient's platelet count and whether there are any symptoms. In mild cases, no treatment is necessary if there is periodic monitoring.
For patients with extremely low platelet counts and/or active bleeding and/or upcoming surgical procedures, medications may be used to elevate platelet levels. The most commonly used are corticosteroids such as prednisone and dexamethasone. Other medications that have been used to raise platelet counts include , intravenous immune globulin (IVIG), , , and .
Splenectomy is typically reserved for adult patients with ITP who have persistent symptomatic thrombocytopenia. Splenectomy is associated with a lifelong increased risk of sepsis with encapsulated bacteria. The risk in adults is estimated at about 1%, with a fatal outcome in approximately 1 per 1500 patient-years.
Pregnancy and Platelet Disorders
Thrombocytopenia, defined as platelet counts of <150 x 109/L, is relatively common in pregnancy, occurring in 7%-12% of pregnancies at the time of delivery. Gestational thrombocytopenia accounts for 70%-80% of cases, hypertensive disorders (such as preeclampsia or ) for 20%, and ITP for about 3%-4%.
Gestational thrombocytopenia is due to a combination of hemodilution, increased consumption of platelets in peripheral tissues, and higher levels of thromboxane A2, leading to increased aggregation of platelets. It is usually mild (platelets between 130-150,000) and does not have a significant impact on mother or fetus. It typically requires no treatment except for periodic monitoring of the platelet and blood count.
Risks from low platelet counts in pregnancy include:
- Inability to have an epidural during labor due to a risk of epidural hematoma which can cause spinal cord damage
- Increased bleeding at the time of vaginal or cesarean section delivery
- Premature delivery if the reduction in platelets is due to severe preeclampsia
- Fetal-neonatal alloimmune thrombocytopenia (rare)
Current guidelines for platelet count for safe delivery/anesthesia are as follows:
- Vaginal delivery: 30,000
- Operative vaginal or caesarian delivery: 50,000
- Epidermal anesthesia: 75,000-80,000
ITP in pregnancy
For women with pre-existing ITP, thrombocytopenia often worsens during pregnancy. Nearly half will require treatment. The decision to begin treatment is dependent on the stage of pregnancy, the platelet count, and whether there are any signs of bleeding. In the first and second trimesters, platelets can be safely maintained at 20,000 unless signs of bleeding or a procedure is required. When in the third trimester, a platelet count >50,000 is preferred. Fortunately, most women will not have major bleeding during delivery.
The first-line treatment is similar to that of non-pregnant patients -- IVIG and glucocorticoids. They have the same efficacy as in nongravid patients and have little risk to the fetus.
The method of delivery for women with ITP is based on obstetrical management. Ideally, the platelet count should be >50,000 for vaginal delivery and >70,000 for a caesarean section or epidural anesthesia. An emergency C-section can be performed under general anesthesia with a platelet count >30,000. Women with ITP are at increased risk for venous thrombosis and routine prophylaxis should be used as indicated. ITP can worsen postnatally and women should be closely monitored for signs of hemorrhage.
After delivery, the neonate should be closely monitored for thrombocytopenia, which develops in 21%-28% of cases, presumably from passive transport of maternal autoantibodies against platelet antigens. A cord blood platelet count can be obtained, and if <100,000, a peripheral blood count should be obtained from the newborn and followed until it surpasses that threshold.
Most women with ITP can breastfeed their infant, although rarely it may cause persistent neonatal thrombocytopenia. This resolves after breastfeeding is stopped. The mother may continue to pump milk to maintain milk supply and resume breastfeeding after the neonatal thrombocytopenia has resolved.
Michele R. Berman, MD, is a pediatrician-turned-medical journalist. She trained at Johns Hopkins, Washington University in St. Louis, and St. Louis Children's Hospital. Her mission is both journalistic and educational: to report on common diseases affecting uncommon people and summarize the evidence-based medicine behind the headlines.