MANAGEMENT OF SICKLE CELL DISEASE

NIH Publication No. 02-2117. Revised May28, 2002 (Forth Edition) National Institutes of Health, National Heart, Lung, and Blood Institute. Download the entire PDF  file for Adobe   Click Here to return to Contents

Chapter 23 CONTRACEPTION AND PREGNANCY

In a large multicenter observational study (1), the most common complication during pregnancy for women with sickle cell disease (SCD) was hypertension (table 1). A high percentage of the pregnancies resulted in preterm deliveries and infants that were small for gestational age. Pain episodes were not increased during pregnancy, and of the pregnancies carried to 28 weeks gestation, 99 percent resulted in live deliveries. This study demonstrated that pregnancy is not contraindicated for women with SCD. However, prenatal care for women with SCD should be managed by a multidisciplinary team that includes an obstetrician, nutritionist, primary care physician, and hematologist. The team must decide who will be responsible for each aspect of the patient’s care. Close monitoring, combined with prompt diagnosis and aggressive treatment of complications during the prenatal and neonatal period by a multidisciplinary team, will contribute to better outcomes.

Oral contraceptives, contraceptive agents administered intramuscularly, and barrier methods are all acceptable choices for women with SCD. Few studies have evaluated oral contraceptives in this population; however, there is no evidence of adverse effects (2).

Intrauterine devices are not optimal, since they may be associated with uterine bleeding and infection, regardless of the presence of SCD.

IMPACT OF HYDROXYUREA ON PREGNANCY

Women and men who are taking hydroxyurea should use contraceptive methods and discontinue the drug if they plan to conceive a child, since hydroxyurea has been shown to be teratogenic in animal models. If conception accidentally occurs when either partner is taking hydroxurea, the couple should be told that there is a paucity of information on which to determine the effect of hydroxyurea on the fetus. However, in the 14 or 15 cases in which hydroxyurea was taken throughout pregnancy, no fetal malformations occurred (3,4).

The prenatal assessment visit serves to provide counseling and outline continued care for the duration of the pregnancy. The primary focus is to identify maternal risks for low birth weight, preterm delivery, and genetic risks for fetal abnormalities. At this time, the physician reviews and discusses the behavior and social patterns that place the patient at risk for sexually  transmitted diseases, illicit drug use, alcohol and tobacco use, and physical abuse. A history of previous cesarean section and uterine curettage should be obtained at prenatal evaluation because of the correlation of the occurrence of placenta previa in patients with previous uterine surgery. Adequate nutritional assessment and the avoidance of precipitating factors that cause painful events should be outlined with this initial visit as well as all subsequent visits. The patient’s prepregnant weight, height, and optimal weight gain in pregnancy will be recorded. Physical exam should also include determination of splenic size.

Initial comprehensive laboratory studies include complete blood count with a reticulocyte index, hemoglobin electrophoresis, serum iron, total iron binding capacity (TIBC), ferritin levels, liver function tests, urine examination and culture, electrolytes, blood ureanitrogen (BUN), creatinine, blood type andgroup, red cell antibody screen, and measurement of antibodies to hepatitis A, B, and C, as well as to HIV. Rubella antibody titre, tuberculin skin test, Pap smear, cervical smear, and gonococcus culture and screening for other sexually transmitted diseases, and bacterial vaginosis also should be performed.

Hepatitis vaccine should be administered when appropriate for patients who are negative for hepatitis B. If asymptomatic bacteriuria is  found, the patient should receive antibiotics in order to prevent urinary tract infection and pyelonephritis.

Return visits are recommended 2 weeks after the initial visit. Low-risk patients are scheduled for monthly visits until the second trimester, when they should be seen every two weeks; in the third trimester, they should be seen every week.

RECOGNITION OF PREGNANCY-INDUCED HYPERTENSION AND DIABETES

For women with SCD, preeclampsia and severe anemia have been identified as risk factors for delivering infants that are small fortheir gestational age (1). In the study summarized in table 1, the incidence of preeclampsia (defined as blood pressure >140/90 mmHg, proteinuria of >300 mg/2 hours, and pathologic edema), and eclampsia (seizures in addition to features of preeclampsia) in pregnant women with SCD was 15 percent (1). The mechanisms for the high incidence of hypertension in this patient population remain unclear; multiple factors such as placental ischemia and endothelial injury have been implicated. Other known risk factors for preeclampsia, even in women without SCD, are nulliparity, a history of renal disease or hypertension, multiple gestation, and diabetes.

Pregnant women with SCD should be observed closely if blood pressure rises above 125/75 mmHg, if the systolic blood pressure increases by 30 mmHg, or diastolic blood pressure increases by 15 mmHg, in association with edema and proteinuria in the second trimester. Preeclampsia, which requires frequent monitoring, can be treated with bed rest at home or in the hospital, if needed.

If preeclampsia is worsening, delivery of the fetus may be required if the gestational age is greater than 32 weeks. Expedited delivery is recommended for uncontrolled hypertension.

INDICATIONS FOR BLOOD TRANSFUSION DURING PREGNANCY

The role of prophylactic transfusions in pregnancy is controversial. One randomized trial (5) and a retrospective study (6) concluded that routine prophylactic transfusions from the onset of pregnancy do not alter the outcome for the fetus or mother. However, one additional study, also retrospective in nature, concluded that prophylactic transfusions, if initiated at about 20 weeks, may be beneficial (7). A realistic approach may be to avoid routine prophylactic transfusions for uncomplicated pregnancies but to consider initiation of transfusions for women who have complications such as preeclampsia, severe anemia, or increasing frequency of pain episodes (8).

Women who have had previous pregnancy losses or who have multiple gestations may benefit from the early use of transfusions to maintain a hemoglobin level above 9 g/dL (8). Women should receive leukoreduced packed red blood cells that have been phenotyped for major and minor antigens. If the primary goal of transfusions is to reduce the percent of sickle hemoglobin (Hb S), and the hemoglobin level is high, one approach is to remove 500 mL of whole blood and transfuse 2 units of packed red blood cells. This procedure can be done manually or by automated methods to obtain a posttransfusion hemoglobin level ranging between 10 and 11 g/dL and to reduce the percentage of Hb S to between 30 and 40 percent of the total hemoglobin concentration.

SICKLE CELL-RELATED EVENTS DURING PREGNANCY

The clinical problems of SCD, such as new onset seizures, hepatopathy, acute anemia, and painful episodes should be evaluated and managed for pregnant women in the same fashion as for women who are not pregnant.

The frequency of previous acute vaso-occlusive painful events is usually predictive of the events during pregnancy, although some patients may experience an increased frequency of pain episodes (9,10). Patients with a chronic pain syndrome should be identified; they may benefit from an individualized care plan.

If interruption of pregnancy is considered at less than 13 weeks, analgesia rather than anesthesia is usually all that is required for suction curettage. Beyond 13 weeks, hypertonic urea solutions are injected into the uterus and contractions are stimulated with prostaglandin F2.

Hypertonic sodium chloride should not be injected because it can cause sickling. Rh-negative women should receive Rh immunoglobulin after therapeutic or spontaneous abortion.  Newer methods for medical termination of pregnancy are available, but their use has not been extensively described in women with SCD (11).

LABOR, DELIVERY, POSTPARTUM CARE, AND COUNSELING

Cardiac function can be compromised because of chronic hypoxemia and anemia. During labor, fetal monitoring is useful to detect fetal distress, which can trigger prompt delivery by cesarean section. If surgery appears imminent, simple transfusion or rapid exchange transfusion can be of benefit depending on the baseline hemoglobin levels. The postpartum patient may require transfusion if she has undergone extensive blood loss during parturition. Venous thromboembolism can also complicate the postpartum course. To prevent this, early ambulation is initiated. 

Counseling is also an important component of postpartum care. Results of the screen for SCD in the infant should be made available to the mother and father, as well as to the pediatrician. Contraception and plans for future pregnancies also should be discussed. If a woman is considering no future pregnancies, she can receive preliminary counseling about tubal ligation for permanent birth control.

1. Smith JA, Espeland M, Bellevue R, et al. Pregnancy in sickle cell disease: experience of the cooperative study of sickle cell disease. Obstet Gynecol 1996;87:199-203.

2. Freie HMP. Sickle cell disease and hormonal contraception. Acta Obstet Gynecol Scand 1983;62:211-7.

3. Diav-Citrin O, Hunnisett L, Sher GD, et al. Hydroxyurea use during pregnancy: A case report in sickle cell disease and review of the literature. Am J Hematol 1999;60:148-50.

4. Byrd DC, Pitts SR, Alexander CK. Hydroxyurea in two pregnant women with sickle cell anemia. Pharmacotherapy 1999;19:1459-62.

5. Koshy M, Burd L, Wallace D, et al. Prophylactic red cell transfusion in pregnant patient with sickle cell disease. A randomized cooperative study. N Engl J Med 1988;319:1447-52.

6. Tuck SM, James CE, Brewster EM, et al. Prophylactic blood transfusion in maternal sickle cell syndromes. Br J Obstet Gynaecol 1987;94:121-5.

7. Morrison JC, Morrison FS, Floyd RC, et al. Use of continuous flow erythrocytapheresis in pregnant patients with sickle cell disease. J Clin Apher 1991;6:224-9.

8. Koshy M, Chisum D, Burd L, et al. Management of sickle cell anemia and pregnancy. J Clin Apher 1991;6:230-3.

9. Koshy M, Burd L, Dorn L, et al. Frequency of pain crisis during pregnancy. Prog Clin Biol Res 1987;240:305-11.

10. Koshy M, Leikin J, Dorn L, et al. Evaluation and management of sickle cell disease in the emergency department (an 18-year experience): 1974-1992. Am J Therap 1994;1:309-20.

11. Christin-Maitre S, Bouchard P, Spitz I. Medical termination of pregnancy. N Engl J Med 2000;342:946-56.

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Last modified: November 09, 2002