Pregnancy, Menstruation & Blood Disorders
Women face several blood-related health issues. Pregnancy increases the risk of some blood problems. In addition, pre-existing blood disorders may become more problematic during pregnancy. Heavy menstruation can sometimes be caused by an underlying bleeding disorder.
Blood Clots During Pregnancy
Pregnant women are approximately five times more likely to develop a blood clot than other women. Blood clots remain a risk for a few weeks after delivery. Clots typically form in the legs or the internal veins of the pelvis or abdomen (deep vein thrombosis). Clots that migrate to the lungs (pulmonary embolism) can be a serious threat to the mother and her baby. Learn more about clotting disorders.
Causes of Blood Clots During Pregnancy
Normal pregnancy produces an increased tendency toward clotting as a natural defense against bleeding during childbirth. In addition, the pregnant uterus compresses several large veins, which increases the pooling of blood and raises the risk of a clot. As with the general population, immobility and long periods of bed rest can also make clots more likely. In addition, some women have an underlying tendency to clot due to a clotting disorder.
Signs of Blood Clot During Pregnancy
Swelling of the legs during pregnancy is normal. However, painful swelling or redness are not normal and could be symptoms of a deep vein thrombosis. Sudden shortness of breath or chest pain could be symptoms of pulmonary embolism.
Treating Blood Clots During Pregnancy
Blood clots that occur during pregnancy can be treated with heparin or low molecular weight heparin. Certain blood thinners, including warfarin, are contraindicated during pregnancy.
Preventing Blood Clots During Pregnancy
Pregnant women can reduce their risk of blood clots by staying active, avoiding long periods of immobility and avoiding excessive weight gain. It is important to drink enough water and take prenatal vitamins. For women with leg swelling, compression stockings can help return blood flow to the heart.
Bleeding During Pregnancy
Bleeding during early pregnancy is common, and it often is not a cause for concern. Bleeding during the second and third trimester is less common and can indicate a health problem. In some cases, late pregnancy bleeding is caused by a problem with the placenta. There are also several hematologic conditions that can lead to bleeding during pregnancy. Learn more about bleeding disorders.
Up to 15 percent of pregnant women develop thrombocytopenia (low blood platelet count). This condition usually develops in the third trimester. Gestational thrombocytopenia is generally very mild and does not need to be treated.
ITP During Pregnancy
Immune thrombocytopenia (ITP) is an autoimmune disease in which platelet cells are attacked by antibodies. If platelet counts become very low, this condition can put the mother’s health at risk (due to blood loss at birth) and sometimes put the baby’s health at risk as well. Symptoms include spotting late in the pregnancy and increased bruising. If platelet counts are very low, patients can experience petechial hemorrhaging, which appears as a bright red rash, particularly on the legs. ITP often does not need to be treated if platelet counts are low but the woman is not experiencing any bleeding problems. ITP that is producing bleeding symptoms can be treated with drugs or proteins that increase platelet counts.
Inherited Bleeding Disorders and Pregnancy
A small percentage of pregnant women have an inherited bleeding disorder such as Von Willebrand disease or an inherited platelet function disorder. These women have a baseline propensity to bleed, so it is important to manage the condition during pregnancy.
Anemia During Pregnancy
Anemia is caused by low red blood cell counts, resulting in lower levels of oxygen being delivered to the body. Symptoms of anemia in pregnant women can include tiredness, weakness, pale skin and rapid heartbeat. There are several causes of anemia during pregnancy:
The volume of plasma in the blood increases during pregnancy. This expansion dilutes the blood, resulting in anemia. Dilutional anemia is most noticeable during the third trimester. It is generally mild and does not need to be treated.
Iron and/or Folate Deficiency
Pregnant women require more dietary iron and folate (a natural form of vitamin B) than non-pregnant women, especially if they have had multiple pregnancies. Deficiency in either can cause anemia. Severe anemia can be treated with iron and folate replacement.
Inherited Anemia Disorders
Inherited anemia problems, such as sickle cell disease, can often become worse during pregnancy. Severe anemia caused by these disorders can pose a serious risk to both mother and baby. Women with congenital anemia disorders should receive close monitoring and careful management by an obstetrician and a hematologist.
Bleeding in the Fetus and Newborn
The fetus can be at risk of abnormal bleeding due to the mother’s inherited bleeding disorders or carrier state (e.g. von Willebrand’s disease or hemophilia). A fetus can also develop severe thrombocytopenia due to the mother becoming sensitized to platelet antigens. Depending on the cause of the fetal bleeding problem, blood or platelet transfusion, replacement coagulation factors, or other treatments are effective.
Abnormal Menstrual Bleeding
Heavy menstrual bleeding (also known as menorrhagia) is a very common problem. Symptoms include periods that last too long (more than 4 to 7 days), large amounts of blood and blood clots in the menstrual flow. Heavy periods may cause iron deficiency and anemia, as women lose blood faster than they can replace it. Women may also experience bleeding between periods (metorrhagia).
Menorrhagia can be caused by a structural reason, such as uterine fibroids. Many women with heavy periods have an unrecognized bleeding disorder such as Von Willebrand disease or a condition such as immune thrombocytopenia.