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Recurrent Pregnancy Loss

(Recurrent Abortion; Habitual Abortion)

By

Antonette T. Dulay

, MD, Main Line Health System

Last review/revision Oct 2022
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Recurrent pregnancy loss is 2 to 3 spontaneous abortions. Determining the cause may require extensive evaluation of both parents. Some causes can be treated.

Etiology of Recurrent Pregnancy Loss

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

Common maternal causes include

  • Uterine or cervical abnormalities (eg, polyps, myomas, adhesions, cervical insufficiency)

  • Maternal (or paternal) chromosomal abnormalities (eg, balanced translocations)

  • Poorly controlled chronic disorders (eg, hypothyroidism, hyperthyroidism, diabetes mellitus, hypertension, chronic kidney disease)

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.

Fetal causes are usually

  • Chromosomal or genetic abnormalities

  • Anatomic malformations

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.

Etiology reference

Diagnosis of Recurrent Pregnancy Loss

  • Clinical evaluation

  • Tests to identify the cause

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.

Treatment of Recurrent Pregnancy Loss

  • Treatment of the cause if possible

Treatment references

  • 1. Brigham SA, Conlon C, Farquharson RG: A longitudinal study of pregnancy outcome following idiopathic recurrent miscarriage. Hum Reprod 14 (11):2868–2871, 1999. doi: 10.1093/humrep/14.11.2868

  • 2. Edlow AG, Srinivas SK, Elovitz MA: Second-trimester loss and subsequent pregnancy outcomes: What is the real risk? Am J Obstet Gynecol 197(6):581.e1–581.e6, 2007. doi: 10.1016/j.ajog.2007.09.016

Key Points

  • Recurrent pregnancy loss is ≥ 2 to 3 spontaneous abortions.

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

  • Chromosomal abnormalities (particularly aneuploidy) may cause 50% of recurrent pregnancy losses.

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