Hemolytic Uremic Syndrome


The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What is hemolytic uremic syndrome during pregnancy?

Hemolytic uremic syndrome (HUS) is a blood vessel and blood condition in which platelets (clotting cells) are destroyed, red blood cells are broken up (hemolysis) leading to anemia, with problems in small blood vessels (microangiopathy) causing kidney failure, and sometimes also damage to other organs, including the heart and brain. Outside of pregnancy, HUS typically is triggered by an intestinal infection with certain strands of Escherichia coli bacteria, and typically strikes children younger than 5 years. However, HUS also is one of several conditions with microangiopathy as the underlying mechanism that can develop in connection with pregnancy. Pregnancy-related HUS, which usually strikes during the three months following delivery (postpartum period) is called pregnancy-associated atypical HUS (p-aHUS) because it happens usually without an E. coli infection.

How common is hemolytic uremic during pregnancy?

One case of p-aHUS develops per every 25,000 pregnancies, usually in the postpartum period.

How is hemolytic syndrome after (or during) pregnancy diagnosed?

Diagnosis of p-aHUS can be extremely challenging, because the symptoms and signs overlap with those of other pregnancy small blood vessel complications, such as HELLP syndrome, acute fatty liver disease of pregnancy (AFLP), and thrombotic thrombocytopenic purpura (TTP). The diagnosis can be made through a combination of very specific results of laboratory testing on your blood and urine, and the timing of symptoms.

Does HUS cause problems during pregnancy?

You will experience kidney dysfunction, which potentially could lead to kidney failure. Women with HUS also have low platelet counts (thrombocytopenia), leading to bleeding (such as from the mouth and nose) bruising, and fatigue, due to the destruction of red blood cells. Other symptoms relating to kidney damage, and or blood cell damage, include fatigue, pallor (you look pale), swelling, decreased urine volume, breathing difficulty, and swelling of ankles, face, and hands. Blood pressure will be elevated, which, together with blood problems can lead to stroke and seizures.

Does HUS cause problems for the baby?

p-aHUS usually strikes in the postpartum period, but if it does occur during pregnancy, the health and life of the baby depends completely on the health and life of the mother, and thus on the success in managing her condition.

What to consider about taking medications when you are pregnant or breastfeeding:

  • The risks to yourself and your baby if you do not treat the HUS
  • The risks and benefits of each medication you use when you are pregnant
  • The risks and benefits of each medication you use when you are breastfeeding

What should I know about using medication to treat HUS during pregnancy?

The main treatment is a specially designed antibody called eculizumab. The effects of this medication on the fetus are not well understood, but the benefits must be weighed against the risk of not having treatment. However, as noted earlier, usually p-aHUS is a postpartum condition.

Who should NOT stop taking medication for HUS during pregnancy?

If you improve with treatment such as eculizumab, your doctor will recommend continuing the treatment.

What should I know about choosing a medication for my HUS during pregnancy?

It is important to stay in communication with your health care provider as the release of new studies over time can change the outlook on the role of specific medications during pregnancy.

You may find Pregistrys expert reports about the medications to treat this condition here. Additional information can also be found in the sources listed below.

What should I know about taking a medication for my HUS when I am breastfeeding?

Eculizumab does not enter breastmilk in large concentrations, so it is thought to be fairly safe in nursing mothers.

What alternative therapies besides medications can I use to treat my HUS during pregnancy?

Supportive measures, such as intravenous (IV) fluid and nutritional management of women with HUS constitute an important component of treatment. In some cases, a procedure called plasmapheresis (a kind of filtering of the blood) may be performed.

What can I do for myself and my baby when I have HUS during pregnancy?

Follow the instructions of your physician. Report any new symptoms and possible side effects of your treatments.

Resources for HUS in pregnancy:

For more information about HUS during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations:

Read the whole report
General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.

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