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Problems with coagulation during pregnancy

Maternal pregnancy complications


Some women have blood that clots poorly and are often said to have “thin” blood. 


This condition may be present from birth, develop later in life, or be caused by side effects of a drug.

In particular, there are coagulation problems with the following conditions:

  • Von Willebrand Disease
  • Haemophilia
  • Deficiency of specific coagulation factors
  • Thrombocytopenia (lack of platelets)
  • Platelet function disorder
  • Ingested anticoagulants

This problem can also be found in women who have had hemorrhages as a result of surgery, childbirth, or an accident.

Pregnancy and childbirth can be problematic for these women since their risk of hemorrhage increases and the unborn child may also have developed a coagulation problem.


The most common manifestations of a blood clotting problem are heavy menstruation and anemia due to iron deficiency.

Tests and procedures

In many cases, pregnancy monitoring in a tertiary centre is recommended to ensure optimal outcomes for both the mother and the fetus. Follow-ups with the Women’s Hemostasis Program team allows comprehensive management by obstetrics, gynecology, hematology, anesthesia, the laboratory and blood bank teams, and pediatrics.

Treatment and follow-up care

Proper preparation allows safe delivery for the mother and baby. Sometimes, however, pregnancy improves the woman’s condition and she has normal coagulation for delivery. In these cases, simple monitoring is necessary. In cases where the woman’s blood remains too thin for delivery, drugs or blood products can be given to protect against bleeding.

For some pregnant women, there is a concern for the baby. Genetic tests can sometimes be done during pregnancy to see if the fetus also has a problem with coagulation. If such a risk is identified, to avoid bleeding in the baby, special care should be taken during delivery such as not using instruments like the vacuum extractor or not taking samples from the scalp. In some situations, it may even be recommended that a Caesarean section be performed to protect the child. After birth, more blood tests can be conducted from umbilical cord blood to check for a coagulation problem.

Resources and useful links

Page by

Dre Catherine Taillefer

About this page
Updated on 1/25/2021
Created on 12/19/2017
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