Thrombocytopenia is the second-most common type of blood disorder in pregnancy, according to Capt. Jeffrey Levy, a doctor of osteopathic medicine at DeWitt Army Community Hospital, in a 2002 Journal of the American Board of Family Medicine article. Thrombocytopenia is a condition in which platelet levels in the blood are lower than normal. Platelets help blood clot. Severe thrombocytopenia can cause bleeding problems at the time of delivery.
Physiologic thrombocytopenia is the normal drop in platelets of around 10 percent in pregnancy, according to the Platelet Disorder Support Association. Other causes include gestational thrombocytopenia, caused by increased destruction of platelets. Gestational thrombocytopenia affects 5 to 8 percent of pregnancies, adds the PDSA. Gestational thrombocytopenia normally occurs in the second or third trimester, generally causes no symptoms and doesn't affect mother or baby.
Immune thrombocytopenic purpura, an autoimmune disease that causes platelet destruction, affects 5 percent of pregnancies and can occur at any point in pregnancy. Immune thrombocytopenia purpura increases the risk of maternal hemorrhage if platelet levels fall below 50,000 platelets per microliter, and also can result in thrombocytopenia in the newborn. Pre-eclampsia, a triad of high blood pressure, edema and protein in the urine, leads to HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome in 10 percent of cases. According to the National Institutes of Health, HELLP syndrome can cause low platelet levels that lead to hemorrhage in the liver.
A blood count is the only way to diagnose thrombocytopenia. A normal platelet count is 150,000 to 450,000 platelets per microliter; levels below 150,000 ppm are called thrombocytopenia. Platelet levels between 100,000 and 150,000 are consider mildly decreased, while levels between 50,000 and 100,000 are considered moderate. Platelet levels below 50,000 are considered severe thrombocytopenia, Levy reports.
Thrombocytopenia normally does not cause symptoms until levels fall below 50,000, according to the Platelet Disorder Support Association. Low platelets can cause small pinpoint spots called petechiae or larger purple spots called purpura, according to the Mayo Clinic. Petechiae and purpura represent bleeding under the skin. Platelet counts below 10,00 can cause spontaneous and sometimes fatal bleeding into the brain or intestine, the Mayo Clinic also warns.
Treatment for thrombocytopenia depends on the cause. Gestational thrombocytopenia requires no treatment outside of regular blood draws to check platelet levels. Treatment for ITP begins when platelet levels fall below 50,000 and include steroid administration to suppress the immune system, according to Levy. Steroids cause remission in 25 percent of patients, while 66 percent respond to the therapy with improved platelet counts. Hypertensive disorders such as pre-eclampsia and HELLP syndrome are treated by delivering the fetus. Platelet counts start returning to normal within 72 hours of delivery, Levy reports.