Antiphospholipid Syndrome: Causes, Symptoms & Diagnosis

By Babygest Staff
Last Update: 01/21/2021

Antiphospholipid syndrome (APS) is an autoimmune disease that affects blood clotting. This can lead to complications during pregnancy, but also to complications in anyone's health.

The cause of APS is the production of antibodies (antiphospholipid antibodies) which act against the phospholipids in the blood cell membranes, causing a state of hypercoagulation.

This state of hypercoagulation can lead to thrombosis or the formation of clots in veins and/or arteries. However, it is not the only characteristic symptom of APS.

Definition of antiphospholipid syndrome

The antiphospholipid syndrome (APS), also known as Hughes Syndrome, is an immunological disorder characterized by hypercoagulability. This syndrome is caused by the creation of antibodies in the wrong way, which makes the blood more likely to clot.

Antiphospholipid syndrome can occur at any age and has a low incidence in the general population. Its frequency is 40 cases per 100,000 inhabitants, although most of these cases are women.


Phospholipids are necessary for the proper functioning of the blood system and coagulation mechanisms. When there are antibodies that attack these phospholipids, the blood clotting function is altered.

There are mainly two types of APS:

Primary APS
appears in isolation, that is, in the absence of other immune pathologies. However, over time, most patients with primary SAP develop lupus. A risk factor for this type of syndrome is the genetic marker HLA-DR7.
Secondary APS
when the syndrome is associated with other pathologies such as lupus or other immune disorders The genetic markers HLA-B8, HLA-DR2 and HLA-DR3 are some of the risk factors for developing secondary APS.

In any case, APS is a multisystemic disease, i.e. it affects several parts and organs of the body and even causes widespread thrombosis. In these cases, the term used is Catastrophic Anti-Phospholipid Syndrome, which is really dangerous for the patient's life.


One of the main signs of APS is thrombosis in the body's arteries or veins. However, it is not the only symptom associated with this disease.

The following are some additional clinical manifestations of the Anti-Phospholipid Syndrome:

  • Blood clots in the legs.
  • Recurrent miscarriages.
  • Stroke.
  • Transient ischemic attack.
  • Rash.

Symptoms related to the neurological system are also common. This is the case with chronic headaches, migraines and seizures. In addition, if there is unexplained bleeding from the nose or gums and/or heavy menstruation, it would be advisable to visit a doctor.

Causes of ASP

The specific reason for the Anti-Phospholipid Syndrome is not known exactly. It is a disease in which antibodies are mistakenly produced and this may be the result of other autoimmune diseases, infection, or certain medications.

However, some factors that increase the risk of ASP have been described:

  • Gender, as there is a higher incidence of ASP in women than in men.
  • Immune system disorders such as lupus or Sjogren's syndrome, for example.
  • Infections such as syphilis or HIV.
  • Family history.

It should be noted that antiphospholipid antibodies can remain in the blood of patients diagnosed with the syndrome for long periods of time, even though episodes of thrombosis only occur occasionally.

Diagnosis and Treatment

The first diagnostic test for the Anti-Phospholipid Syndrome consists of a blood test where it will be revealed if there is any alteration in the coagulation. In addition, this test will also reflect the presence of antiphospholipid antibodies. If these antibodies are detected, the test will need to be repeated at 12 weeks for confirmation.

On the other hand, the first phase of treatment of this disease will consist of the administration of anticoagulants to dissolve these blood clots. Normally, the most commonly used anticoagulant is heparin. Another option is to use vitamin K inhibitors, such as Warfarin, as these drugs block the activation of clotting factors.

However, Warfarin is not recommended in pregnant patients, since this drug is able to cross the placenta and is harmful to the fetus.

It is of utmost importance that APS patients have rigorous, multidisciplinary medical management. In addition, it is essential that patients know the details of the disease, as well as the possible risks attached to it.

Antiphospholipid syndrome during pregnancy

Currently, treatments for APS are usually effective and the vast majority of women with this disease achieve pregnancy.

Although it is not a contagious or terminal pathology, it can be especially serious during pregnancy because of its action on fetal development. Among the most common complications of APS in pregnancy are the following:

  • Arterial or venous thrombosis, especially in the placenta.
  • Decreased maternal platelets.
  • Problems in placental circulation
  • Recurrent pregnancy loss.
  • Delayed fetal growth.
  • Premature births.
  • Fetal death.
  • Maternal high blood pressure (severe pre-eclampsia).

As we have said, antiphospholipid antibodies interfere with blood clotting, leading to the appearance of thrombi or intravascular clots. If this occurs during pregnancy, the uterine arteries that "feed" the placenta would be affected and as a consequence, the arrival of nutrients and oxygen to the fetus would be deficient and could trigger the problems already mentioned.

In other cases, the only solution for women with APS who want to have a child is to resort to surrogacy. This would be the option for those women where pregnancy is completely contraindicated because it would pose a serious danger to their life.

FAQs from users

Does antiphospholipid syndrome run in the family?

By Marta Barranquero Gómez (embryologist).

Most patients with this syndrome have developed it sporadically, i.e. without any family history of the syndrome. However, it is true that an increasing number of studies indicate a genetic association.

This means that there is a greater likelihood of developing APS if the parents have the disease.

Is antiphospholipid syndrome contagious?

By Marta Barranquero Gómez (embryologist).

The answer is no. Antiphospholipid syndrome is an immune disease caused by the presence of antibodies that act against phospholipids, which are necessary to regulate the clotting process. For this reason, this pathology is characterized by a situation of hypercoagulation.

Which tests do I need to undergo for an APS diagnosis?

By Marta Barranquero Gómez (embryologist).

The fundamental test for the diagnosis of APS consists of a blood test. The parameters to be studied in the laboratory are anticardiolipin, lupus anticoagulant, and Anti-beta2-glycoprotein-1.

If a positive result is obtained in any of these three tests, it will be necessary to repeat the tests a second time after about 3 months.

What are antiphospholipid antibodies?

By Marta Barranquero Gómez (embryologist).

Antiphospholipid antibodies are antibodies whose action is to attack phospholipids, proteins in the membrane of blood cells. When the antibodies attack the phospholipids, a hypercoagulable situation occurs, i.e. an excess of blood coagulation.

Suggested for you

If you are interested in learning about other autoimmune diseases that can affect pregnancy, we recommend visiting the following article: What are autoimmune diseases and how do they affect fertility?

As mentioned, pregnancy may be contraindicated in some women with the syndrome. In these cases, it will be necessary to resort to surrogacy in order to become mothers. If you want to get information about the whole process, you can visit this link: How does surrogacy work - Advice and steps to follow.

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Carmi O, Berla M, Shoenfeld Y, Levy Y. Diagnosis and management of catastrophic antiphospholipid syndrome. Expert Rev Hematol. 2017 Apr;10(4):365-374. doi: 10.1080/17474086.2017.1300522.

Cervera R. Antiphospholipid syndrome. Thromb Res. 2017 Mar;151 Suppl 1:S43-S47. doi: 10.1016/S0049-3848(17)30066-X.

Garcia D, Erkan D. Diagnosis and Management of the Antiphospholipid Syndrome. N Engl J Med. 2018 May 24;378(21):2010-2021. doi: 10.1056/NEJMra1705454.

Ruiz-Irastorza G, Crowther M, Branch W, Khamashta M. Antiphospholipid syndrome. Lancet. 2010 Oct 30;376(9751):1498-509. doi: 10.1016/S0140-6736(10)60709-X.

Sammaritano L. Antiphospholipid syndrome. Best Pract Res Clin Rheumatol. 2020 Feb;34(1):101463. doi: 10.1016/j.berh.2019.101463.

Schreiber K, J Hunt B. Managing antiphospholipid syndrome in pregnancy. Thromb Res. 2019 Sep;181 Suppl 1:S41-S46. doi: 10.1016/S0049-3848(19)30366-4.

FAQs from users: 'Does antiphospholipid syndrome run in the family?', 'Is antiphospholipid syndrome contagious?', 'Which tests do I need to undergo for an APS diagnosis?' and 'What are antiphospholipid antibodies?'.

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