Frequency of factors associated with habitual abortion in 197 couples.

OBJECTIVE

To determine the frequency of factors associated with habitual abortion in 197 couples.

DESIGN

Prospective cohort study.

SETTING

The British Columbia Recurrent Pregnancy Loss Program, located in a tertiary care academic center.

INTERVENTIONS: Diagnostic screening protocol.

MAIN OUTCOME MEASURES: Genetic, endocrine, infectious, anatomical, and autoimmune factors associated with habitual abortion.

RESULTS

A structural genetic factor was identified in 3.5% of the couples. An endocrine factor, including luteal phase deficiency and hypothyroidism, was identified in 20% and an infectious factor was identified in 0.5% of the couples. An anatomical factor, including various müllerian tract anomalies and severe intrauterine adhesions, was found in 16% and an autoimmune factor, including the antiphospholipid antibody syndrome and the undifferentiated connective tissue syndrome, was identified in 20% of the couples. Eighty-four couples who completed the diagnostic screening protocol were classified as having unexplained habitual abortion. Of these 84 couples, 65% were subclassified as primary, 27% were subclassified as secondary, and 7% had unclassified unexplained habitual abortion.

CONCLUSIONS

This large-scale study identified genetic, endocrine, infectious, anatomical, or autoimmune factors in approximately 60% of couples with habitual abortion.