Recurrent Pregnancy Loss

Causes of recurrent pregnancy loss may be maternal, paternal, fetal, or placental.

Common maternal causes include

Acquired thrombotic disorders Thromboembolic Disorders in Pregnancy In the US, thromboembolic disorders— deep venous thrombosis (DVT) or pulmonary embolism (PE)—are a leading cause of maternal mortality. During pregnancy, risk is increased because Venous capacitance... read more (eg, related to antiphospholipid antibody syndrome Antiphospholipid Syndrome (APS) Antiphospholipid syndrome is an autoimmune disorder characterized by venous and arterial thrombosis or pregnancy complications (eg, recurrent miscarriage) and persistent autoantibodies to phospholipid-bound... read more with lupus anticoagulant, anticardiolipin [IgG or IgM], or anti-beta2 glycoprotein I [IgG or IgM]) are associated with ≥ 3 recurrent losses after 10 weeks, after other maternal and genetic causes have been excluded. Loss of one or more apparently normal pregnancies after 10 weeks can raise suspicion of antiphospholipid antibody syndrome (1 Etiology reference Recurrent pregnancy loss is ≥ 2 to 3 spontaneous abortions. Determining the cause may require extensive evaluation of both parents. Some causes can be treated. Causes of recurrent pregnancy... read more ). The association with hereditary thrombotic disorders is less clear but does not appear to be strong, except for possibly factor V Leiden mutation.

Paternal causes are less clear, but risk of miscarriage is higher if the father has certain semen analysis abnormalities. Paternal age > 35 has been studied, but data about increased risk of spontaneous abortion were conflicting.

Placental causes include preexisting chronic disorders that are poorly controlled (eg, systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic, multisystem, inflammatory disorder of autoimmune etiology, occurring predominantly in young women. Common manifestations may include arthralgias and... read more [SLE], chronic hypertension Hypertension Hypertension is sustained elevation of resting systolic blood pressure (≥ 130 mm Hg), diastolic blood pressure (≥ 80 mm Hg), or both. Hypertension with no known cause (primary; formerly, essential... read more ).

Fetal causes are usually

Chromosomal abnormalities Overview of Chromosomal Anomalies Chromosomal anomalies cause various disorders. Anomalies that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect sex chromosomes... read more in the fetus may cause 50% of recurrent pregnancy losses; losses due to chromosomal abnormalities are more common during early pregnancy. Aneuploidy is involved in up to 80% of all spontaneous abortions occurring at < 10 weeks gestation but in < 15% of those occurring at ≥ 20 weeks.

Whether a history of recurrent pregnancy loss increases risk of fetal growth restriction and premature delivery in subsequent pregnancies depends on the cause of the losses.

The diagnosis of recurrent pregnancy loss is clinical, based on history of 2 or 3 prior spontaneous abortions.

Evaluation for recurrent pregnancy loss should include the following to help determine the cause:

Cause cannot be determined in up to 50% of women. Screening for hereditary thrombotic disorders is not routinely recommended unless supervised by a maternal-fetal medicine specialist.

Some causes of recurrent pregnancy loss can be treated. If the cause cannot be identified, the chance of a live birth in the next pregnancy is 27 to 75% (1 Treatment references Recurrent pregnancy loss is ≥ 2 to 3 spontaneous abortions. Determining the cause may require extensive evaluation of both parents. Some causes can be treated. Causes of recurrent pregnancy... read more , 2 Treatment references Recurrent pregnancy loss is ≥ 2 to 3 spontaneous abortions. Determining the cause may require extensive evaluation of both parents. Some causes can be treated. Causes of recurrent pregnancy... read more ).