1
Forth stage
Obstetric
Lec-11
د . احمد جاسم
1/1/2014
Immunological disorder during pregnancy
Autoimmune disease refers to various disorders characterized by immune mediated
damage to various tissues .
Normally the immune system discriminates between self and non self antigen and is
tolerant of non-self antigen ,however failure of self tolerance can lead to sever ,debilitating
illness.
Pregnancy with autoimmune disease can be risky because the fetus can be affected by
maternal autoimmunity.
Autoimmune disease can include:
Antiphospholipid syndrome
Systemic lupus erythematosis
Autoimmune thrombocytopenia
Mysthenia gravis
Rheumatoid arthritis
Autoimmune thyroid disease
Autoimmune diabetes mellitus
Antiphospholipid syndrome :
Autoimmune condition characterized by the production of moderate to high level of Anti-
phospholipid antibodies and certain thrombotic features as thrombotic phenomena (
venous or arterial including stroke) , autoimmune thrombocytopenia and pregnancy loss .
Others are :
-livedo reticularis .
-coombs positive haemolytic anaemia .
-cardiac valvular lesion .
APS can be classified as :
Primary APS. (unrelated to underlying Auto-immune disease).
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Secondary APS . (with underlying autoimmune disease as SLE ).
Patient diagnosed as having Antiphosphlipid Syndrome should have at least one clinical
feature of the syndrome along with moderate to high levels of aPL .
There are three aPL for which well established assay are available :
-Biological false – positive test for syphilis (BF-STS).
-Lupus anticoagulant (LA).
-Anticardiolipin antibody (aCL).
Serial assessment of the antibodies testing (6 weeks apart) to confirm the high level of
antibody in patients with initial negative or low positive level of antibody.
Maternal risks :
1.Thrombosis and stroke:
Venous thrombosis accounts for 65-70% of episodes .
lower limbs is the single most common site of involvement ,but no part of
vasculature is immune.
aPL are the only identifiable factor predisposing to 4-28% of cases of stroke in other
wise healthy women under age of 50 years .
Over half of cases of thrombotic episode in APS patient occurs in relation to
pregnancy or the use of COC that warrant treatment with heparin .
2,Pre-eclampsia : there are high rate of cases of PE in APS and not reduced by either
treatment of APS.
Fetal risk :
Pregnancy loss:
About 50% of pregnancy loss in women with APS are fetal death ,there is high rate of aPL
inwomen with recurrent pregnancy. The importance of identifying APS lies not in it’s
prevalence but in it’s implication for the patient and that it is a potentially treatable cause
of pregnancy loss
.
Fetal growth restriction : aPL are associated with fetal growth restriction even in
treated pregnancies fetal growth restriction is up to 30% .
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Fetal distress : FD appears relatively commonin aPL , and occurs in half of patients (
even in treated pregnancy).
Preterm birth : 1/3 of patients delivered preterm even in treated patients.
Management options:
Prepregnancy:
-confirm the high level of aPL.
-inform the mother of the potential fetal and maternal problems.
-If the patient has SLE then the risk of exacerbation can also be discussed ,and risk of
anaemia ,thrombocytopenia , and underlying renal disease.
-anticoagulant therapy is given to prevent thrombosis during pregnancy and 1 month
postpartum.
Prenatal :
-Antenatal visit twice weekly in the 1
st
trimester, weekly in the 2
nd
trimester .
-Fetal ultrasound every 3-4 weeks after 17-18 weeks to detect IUGR , oligohydramnios ,
doppler recording .
-Fetal surveillance : daily fetal movement counts , once weekly non stress tests , amniotic
fluid volume measurements are started at 26-28 weeks.
-Treatment options :
Glucocorticoid with low dose aspirin :
There are numerous minor adverse effects as DM and PIH , increased neonatal morbidity
(preterm delivery ,low birth weight ). High dose prednisone (40 mg/day)
Heparin and low dose aspirin :
It’s now the preferred option for improving outcome . It prevent placental thrombosis and
infarction . Heparin prophylactic dose 5000 -10000 U twice daily.
Heparin therapy is started after demonstration of a live embryo by ultrasound (5-7 week
gestation) .
Heparin therapy is not without risk , the most common are :
Bleeding .
Heparin induced osteoporosis . (Ca suppl.)
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Uncommon ideosyncratic thrombocytopenia.
(independent from the dose and route occur in <5%). Occasionally associated with
thromboembolic events or DIC .
Heparin is preferred over prednisone because has fewer side effects and can provide
prophylaxis against thrombosis .
Heparin and high dose prednisone should not used simultaneously will predispose to
osteopenic fractures and combination of the drugs is no better than either drugs alone.