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CHAPTER 8 conditions can be exacerbated by pregnancy and can result in adverse repro-

HEMATOLOGY DURING ductive outcomes as well as maternal venous thromboembolism. The stron-
gest evidence for an association between a thrombophilia and recurrent fetal
PREGNANCY loss exists for antiphospholipid antibody syndrome; however, evidence is
mounting for a connection between inherited thrombophilias and the severity
of some complications of pregnancy. These thrombophilias increase the risk
of maternal venous thromboembolism in pregnancy and the puerperium.
Martha P. Mims Treatment of hematologic malignancies in pregnancy can present a difficult
dilemma both in terms of staging studies and management. In many cases
of Hodgkin lymphoma, treatment can be delayed safely until after delivery.
SUMMARY In contrast, in aggressive lymphomas and acute leukemias rapid initiation of
chemotherapy is often necessary to save the life of the mother. In general, the
Normal pregnancy involves many changes in maternal physiology, including teratogenic effects of chemotherapy are greatest in the first trimester; how-
alterations in hematologic parameters. These changes include expansion in ever, care must be taken in later trimesters to avoid cytopenias of both mother
maternal plasma volume. The increase in plasma volume is relatively larger and fetus at delivery. Hemorrhagic and thrombotic complications associated
than the increase in red cell mass resulting in a decrease in hemoglobin con- with pregnancy in females with essential thrombocythemia and polycythemia
centration. An increase in the levels of some plasma proteins alters the bal- vera present a unique challenge because of the lack of controlled trials in these
ance of coagulation and fibrinolysis. Worldwide, the predominant cause of situations.
anemia in pregnancy is iron deficiency. Fetal requirements for iron are met
despite maternal deficiency, but maternal iron deficiency has a number of
adverse consequences including an increased frequency of preterm delivery
and low-birth-weight infants. Bleeding disorders in pregnancy are a common BLOOD VOLUME, ERYTHROPOIETIN
reason for hematologic consultation and evoke concern for both the mother
and child. Life-threatening bleeding caused by disseminated intravascular LEVEL, AND HEMOGLOBIN
coagulation is seen with some complications unique to pregnancy, including CONCENTRATION
placental abruption, retained dead fetus, and amniotic fluid embolism. von
Willebrand disease is the commonest inherited bleeding disorder, but because Maternal blood volume increases by an average of 40 to 50 percent above
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of increases in factor VIII level and von Willebrand factor during pregnancy, the nonpregnant level. Plasma volume begins to rise early in pregnancy,
excessive bleeding at delivery is rarely a problem in such patients. Factor levels with most of the escalation taking place in the second trimester and
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fall rapidly postpartum, and serious hemorrhage can occur during this period. prior to week 32 of gestation. Red cell mass increases significantly
Carriers of hemophilia A and B should be monitored during pregnancy to beginning in the second trimester and continues to expand throughout
pregnancy, but to a lesser extent than plasma volume. Erythropoietin
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determine if factor levels will be adequate for delivery at term. Caution should levels increase throughout pregnancy, reaching approximately 150 per-
be exercised at delivery and during the first few days of life with offspring of cent of their prepregnancy levels at term. The overall effect of these
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hemophilia carriers until hemophilia testing is completed and the infant’s sta- changes in most women is a slight drop in hemoglobin concentration,
tus is known. Acquired hemophilia as a result of factor VIII autoantibodies is which is most pronounced at the end of the second trimester and slowly
rare, but can occur during pregnancy or the puerperium. Thrombocytopenia improves approaching term.
is not uncommon in pregnancy, and its causes include several conditions that
are unique to pregnancy, such as preeclampsia. Idiopathic thrombocytopenic PLATELET AND WHITE CELL COUNTS
purpura (ITP) is common, it is often exacerbated in pregnancy, and is managed The effect of pregnancy on maternal platelet count is somewhat more
conservatively if possible; close followup of newborns of mothers with ITP is controversial; some studies demonstrate a mild decline in platelet count
essential. HELLP (hemolysis, elevated liver enzymes, and low platelet count) over the course of gestation, whereas others do not. In general, white
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syndrome and TTP (thrombotic thrombocytopenic purpura)/hemolytic uremic cell counts rise during pregnancy with the occasional appearance of
syndrome are also seen in pregnancy and the puerperium. HELLP syndrome myelocytes or metamyelocytes in the blood. During labor and the early
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is managed by immediate delivery, if possible, whereas TTP, usually, can be puerperium, there is a rise in the leukocyte count. Leukocytosis appears
managed with plasma exchange. Inherited and acquired prothrombotic to be linearly related to the duration of labor. 8
PLASMA PROTEINS
The levels of some plasma proteins also increase during pregnancy.
Acronyms and Abbreviations: DDAVP, desmopressin acetate, a synthetic analogue In particular, C-reactive protein concentration is higher in pregnant
of the pituitary hormone vasopressin; DIC, disseminated intravascular coagulation; women and rises even further during labor. Erythrocyte sedimentation
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ESR, erythrocyte sedimentation rate; ET, essential thrombocythemia; HELLP, hemoly- rate (ESR) rises during pregnancy, and is affected by both hemoglobin
sis, elevated liver enzymes, low platelets syndrome; ITP, idiopathic thrombocytopenic concentration and gestational age. The rise in ESR during pregnancy,
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purpura; PNH, paroxysmal nocturnal hemoglobinuria; PT, prothrombin time; PTT, in large part a result of an increase in levels of plasma globulins and
partial thromboplastin time; PV, polycythemia vera; TTP, thrombotic thrombocy- fibrinogen, makes its use as a marker of inflammation difficult. The
topenic purpura; VTE, venous thromboembolism; VWD, von Willebrand disease; VWF, levels of many of the procoagulant factors increase during pregnancy
von Willebrand factor. whereas activity of the fibrinolytic system diminishes in preparation for
the hemostatic challenge of delivery. Plasma levels of von Willebrand

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