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Immune Thrombocytopenia in Pregnancy

Essay 2016 9 Seiten

Medizin - Gynäkologie, Andrologie

Leseprobe

Abstract

Thrombocytopenia occurs mostly in pregnant women, in which immune thrombocytopenia is believed to be one of the least prevalent forms of thrombocytopenia. Clinical studies indicate that immune thrombocytopenia occurs at a low rate of 11% compared to gestational thrombocytopenia, which occurs at a rate of 59%. However, it is characterized with moderate and severe thrombocytopenia with platelet counts decreasing below 100x109/L. Ordinarily, immune thrombocytopenia is caused by auto-immune reactions against platelets by anti-platelet antibodies, which destroy glycoprotein membranes forming platelet membranes.

Immune thrombocytopenia in pregnancy causes several risks to women and newborns. ITP pregnant women experience high risks of maternal hemorrhage compared to those suffering from other forms of thrombocytopenia. Despite the low percentage of ITP rates in pregnant women, extensive monitoring and management are required, primarily during prenatal care to reduce the risks associated with the disorder.

On the other hand, immune thrombocytopenia in pregnancy presents numerous neonatal concerns. The notion that, immune thrombocytopenia influences delivery alternatives has been disapproved by the recent clinical reports, which are based on randomized clinical trials. In the past, cesarean delivery was considered as a significant obstetric indication in ITP pregnant women. Currently, vaginal birth has been found to reduce trauma in newborns born of ITP mothers.

Moreover, treatment provided to immune thrombocytopenic women prior or during pregnancy causes neonatal concerns. For instance, splenectomy treatment prior to pregnancy has been found to increase free anti-platelet antibodies in maternal circulation, causing a significant risk of anti-platelet reactions in the fetus.

It has also been confirmed that, IgG anti-platelet antibodies are transferred from maternal circulation into the fetal body, and this may predispose the fetus to neonatal alloimmune thrombocytopenia (NAIT), leading to neonatal hemorrhage.

In conclusion, maternal and neonatal concerns associated with ITP can be reduced through platelet count monitoring during prenatal care.

IMMUNE THROMBOCYTOPENIA IN PREGNANCY

Thrombocytopenia occurs mostly in pregnant women, and they are characterized by a low platelet count. Platelet levels below 150x109/l are associated with thrombocytopenia. However, thrombocytopenia is classified into three categories in accordance to the associated platelet level count. The main categories are mild, moderate and severe thrombocytopenia. In practice, pregnant women with platelet counts ranging between 100 – 150x109/l are said to be suffering from mild thrombocytopenia while those who record platelet levels ranging between 50 – 100x109/l suffer from moderate thrombocytopenia. Pregnant women whose platelet count decreases below 50x109/l are said to be suffering from severe thrombocytopenia (Kam, Liew & Thompson, 2004).

It has been identified that, thrombocytopenia are caused by decreased platelet production in the patient’s hematopoietic system. The second cause of thrombocytopenia is the accelerated destruction of platelets, primarily through autoimmune reactivity, owing to an autoimmune disorder. This condition has been found to be common in pregnant women with 10 percent of women experiencing thrombocytopenia (Kekomaki et al., 2000).

Immune thrombocytopenic purpura (ITP) is one of the most live-threatening forms of thrombocytopenia, and it is categorized as severe thrombocytopenia because it is characterized with platelet counts below 50x109/l. It occurs at a rate of 5 percent in pregnant women. McCrae and Stavrou (2009) report “immune thrombocytopenia (ITP) occurs in one or two of every 1,000 pregnancies, and accounts for 5% of cases of pregnancy-associated thrombocytopenia” (p. 2). Clinical research indicates that immune thrombocytopenia is caused by autoimmune reactions in the reticular endothelial system, in which platelet auto-antibodies destroy glycoprotein complexes forming the platelet membrane. As a result, platelet production in the reticular endothelial system decreases causing a significant decrease in platelet count in the circulatory system of the affected individual.

In most cases, immune thrombocytopenia causes a high risk of maternal hemorrhage. Therefore, treatment is required with extensive monitoring during the pre-natal and post-natal period to reduce the risks associated with the condition. However, it is worth noting that, immune thrombocytopenia causes minor risks on the newborn (Burstein et al. 2006).

Immune thrombocytopenia in pregnant women has been reviewed by researchers in the field of medicine to unravel the underlying mysteries related to the condition. In the last decade, several research studies advanced the clinical understanding on immune thrombocytopenia, and this has enhanced diagnosis, management and treatment approaches. For instance, immune thrombocytopenia was believed to cause significant risks on the infants who are born of immune thrombocytopenic women, but that issue has been clarified through advanced clinical trials (Cines & Blanchette, 2002). Currently, there is evidence that immune thrombocytopenia in pregnant women does not cause fatal risks to newborns.

In a clinical research study conducted, in 2005, by Burstein and his colleagues at Soroka University Medical Center, it was found out “there is a minor risk of thrombocytopenia in the newborn” (p. 2). This study was aimed at investigating obstetric risk factors, pregnancy outcomes and complications associated with immune thrombocytopenia in pregnant women. It studied the clinical implications of moderate to severe thrombocytopenia by comparing 199 pregnant participants whose platelet count levels were below 100x109/l, with 201 non-thrombocytopenia pregnant women. Their study included pregnant women who conceived between January 2003 to April 2004, and their methodology involved Mantel-Haenszel procedure (Burstein et al. 2006).

Clinical study results indicated that, immune thrombocytopenic women accounted for 11.05% of the study population while gestational thrombocytopenia was found to be the most common occurring form of thrombocytopenia with a total percentage of 59.3%. In regard to age of the participants, women without thrombocytopenia were found to be of younger ages compared to those suffering from thrombocytopenia. Their average age was estimated at 28 years while thrombocytopenic women recorded an age average of 30 years.

It was also identified that, immune thrombocytopenia was responsible for preterm deliveries, in which placental abruption occurred at higher rates in thrombocytopenic women than normal women. However, it is worth noting that, the high cases of preterm deliveries and placental abruption occurred after controlled labor induction, which was performed through the use of the Mantel–Haenszel procedure.

On the other hand, infants of thrombocytopenic women were recorded to have higher rates of Apgar scores, which were below 7 in 5 minutes, than infants born of non-thrombocytopenic women. Intra-uterine growth restriction was found to occur at a rate of 95 percent among thrombocytopenic women, in which women suffering from immune thrombocytopenia accounted for the highest percentage compared to those suffering from thrombotic thrombocytopenic purpura and anti-phospholipid antibodies (APLA) syndrome (Chehal et al.,2004). Conclusively, this research indicated that immune thrombocytopenia in women causes favorable perinatal complications compared to those suffering from HELLP syndrome and preeclampsia (Burstein et al. 2006).

The low prevalence of immune thrombocytopenia in pregnant women was also reaffirmed, in 2010, by a clinical study report released by the Cleveland Clinic Foundation. McCrae (2010) reported, “ITP is an uncommon cause of thrombocytopenia in pregnancy, occurring in between 1 in 1000 and 1 in 10,000 pregnant women as opposed to secondary ITP, which develops in association with viral infection” (p. 397). In addition, this study showed that an estimation of one-third of pregnancy-associated immune thrombocytopenia is diagnosed during pregnancy compared to two-thirds which is diagnosed first in non-pregnant women with preexisting diseases such as Human Immunodeficiency Virus (HIV), Helicobacter pylori and hepatitis c viral infection (McCrae, 2010).

On the other hand, immune thrombocytopenia has been found to become complicated during the third trimester of pregnancy, owing to a decrease in platelet count, primarily below 50x109/l, but most neonates record healthy outcomes. In a case study conducted in 2012, a woman with history of immune thrombocytopenia “delivered a healthy neonate with a platelet count of 125 × 109/L” (Gernsheimer, James & Stasi, 2012 p. 44).

In regard to the management of immune thrombocytopenia in pregnancy, it has been found out the mode of delivery among immune thrombocytopenic women does not depend on the condition. Instead, delivery modes in immune thrombocytopenic pregnant women should be based on obstetric indications. However, obstetric procedures, which increase hemorrhagic risk of the fetus such as vacuum extraction should be avoided (Gernsheimer, James & Stasi, 2012). In the past, immune thrombocytopenia in pregnant women was considered as a significant indication for cesarean delivery. However, recent clinical research reports do not indicate any significant association between immune thrombocytopenia with the modes of delivery among pregnant women suffering from the condition.

In contrast, investigators recommend the use of cesarean delivery in all pregnant women with history of immune thrombocytopenia. However, performing cesarean delivery is for the sake of the newborn, but not necessarily based on obstetric indications requiring safety measures to be observed to reduce the risk of the mother. This delivery is recommended for immune thrombocytopenic women to minimize to the newborns (Millar, 2012). In most cases, newborns delivered vaginally experience trauma during birth, and this raises a significant neonatal concern. Therefore, some investigators suggest that cesarean delivery can help to reduce trauma among newborns delivered by immune thrombocytopenic women.

In practice, these recommendations for performing cesarean delivery on immune thrombocytopenic women appear unrealistic. This was overruled after a comprehensive review of 474 newborns who were delivered by thrombocytopenic mothers using vaginal and cesarean deliveries. In this review, cesarean delivery was found to be associated with increased incidences of bleeding complications compared to vaginal delivery. Of the 474 newborns involved in the review, 30 % of newborns delivered by cesarean birth experienced bleeding complications compared to 29% of newborns delivered by vaginal birth. Millar (2012) remarks “Cesarean delivery has not been demonstrated to prevent bleeding complications in thrombocytopenic newborns” (par. 5).

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Details

Seiten
9
Jahr
2016
ISBN (eBook)
9783668576889
ISBN (Buch)
9783668576896
Dateigröße
406 KB
Sprache
Englisch
Katalognummer
v381239
Institution / Hochschule
Egerton University
Note
2
Schlagworte
pregnancy thrombocytopenia platalet

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Titel: Immune Thrombocytopenia in Pregnancy