Pregnancy and Hematology

Women with hematologic (blood) conditions, including inherited and acquired blood disorders, can face unique challenges during pregnancy. Pregnancy increases the risk of clotting, and delivery can increase risks of hemorrhage in patients with coagulation disorders. Iron and folate needs also change during pregnancy, which can complicate anemia and other blood disorders.

Pregnancy and Hematology Topics

Hematologic Condition Types

Pre-existing blood conditions and conditions arising during pregnancy may include:

Bleeding and coagulation disorders

Clotting disorders

  • Factor V Leiden
  • Prothrombin gene mutation
  • Protein C and S deficiencies
  • Antiphospholipid antibodies
  • Antithrombin III deficiency
  • Other disorders


  • Hemoglobinopathies like sickle cell disease or thalassemias
  • Iron deficiency anemia
  • Anemia of chronic disease
  • Bone marrow disorders
Optimal Care for Hematologic Conditions and Pregnancy

Women with blood disorders require specialized pregnancy care. Pregnancy hormones impact many hematologic conditions, causing an increased risk of blood clots with some disorders. Other blood conditions can result in increased bleeding at the time of delivery. Some women may require transfusions or frequent blood tests during and after the pregnancy. For many women, safe childbirth necessitates close, interdisciplinary care with complex plans for monitoring and treatment in labor.

Common Hematology Tests

Complete blood count (CBC), which includes:

  • White blood cell count (WBC)
  • Red blood cell count (RBC)
  • Platelet count
  • Hematocrit red blood cell volume (HCT)
  • Hemoglobin concentration (HB). This is the oxygen-carrying protein in red blood cells.
  • Differential white blood count
  • Red blood cell indices (measurements)

To aid in diagnosing anemia, certain cancers of the blood, inflammatory diseases, and to monitor blood loss and infection

Platelet count (usually done as part of the CBC)
To diagnose and/or to monitor certain types of bleeding and clotting disorders.

Prothrombin time (PT), Partial Thromboplastin Time (PTT), International Normalized Ratio (INR)
To evaluate bleeding and clotting disorders and to monitor anticoagulation (anticlotting) therapies.

Preconception Planning

For women with known blood disorders, a consultation with the medical team before conception (pregnancy) can help families understand how pregnancy may impact the disease, how the blood disorder will impact the pregnancy, and whether there are any risks to the baby. This consultation will address what medications are safe in pregnancy, and whether any medications should be changed to optimize pregnancy outcomes. A plan for surveillance and management of mother and baby during and after the pregnancy will be developed. For women with inherited blood disorders, genetic counselors can provide important information regarding the risk that the baby will also develop these disorders.

Prenatal Care

A detailed prenatal care plan will address the mother’s individual health issues, as well as surveillance for the baby. Your maternal fetal medicine physician and hematologist will work together to optimize outcomes and begin planning for a safe birth. For some patients, anticoagulation (blood thinners) will be adjusted, and others may require blood tests or transfusions. Families can meet with genetic counselors to discuss the risk that the baby will be affected, and testing of the baby is available for some disorders.

Delivery and Postpartum Care

A thorough birth plan will be developed by your team, including experts in maternal-fetal medicine, hematology, and anesthesiology. Close monitoring through birth and the postpartum period is essential for mothers with hematologic disorders, and many complications can be avoided through advance planning for this period.

We work as a team to provide the best outcomes for mothers, babies, and families, in the setting of complicated hematologic disorders.

Maternal-Fetal Medicine and Hematology

At Brigham and Women’s Hospital, experts in maternal-fetal medicine have formed an innovative collaboration with specialists in hematology to provide multidisciplinary care for patients with blood disorders. The team, in conjunction with anesthesiologists and genetic counselors, provides preconception consultations, as well as advanced prenatal, delivery, and postpartum care. In addition, these specialists also work closely with the BWH Blood Bank to ensure the safety during pregnancy, birth, and postpartum course.

Appointments and Locations

To schedule an appointment or to learn more about our services, please contact us at (617) 732-4840.

Our program is located at:

Brigham and Women’s Hospital
75 Francis Street
Boston, MA 02115

Pregnancy and Hematology Program Leaders

Nicole A. Smith, MD, MPH
Division of Maternal-Fetal Medicine

Jean Marie Connors, MD
Hematology Division

Elisabeth M. Battinelli, MD, PhD
Hematology Division

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