Terminology for Two Mid-Trimester Spontaneous Abortions
Two mid-trimester spontaneous abortions is termed "recurrent spontaneous abortion" (RSA), which is classically defined as three or more consecutive pregnancy losses prior to 20 weeks' gestation, though some definitions include two or more losses.
Standard Definition
- Recurrent spontaneous abortion (RSA) is traditionally defined as three or more consecutive spontaneous abortions prior to 20-28 weeks' gestation 1, 2
- This condition affects approximately 2-5% of all women of childbearing age 2
- The term "spontaneous abortion" is synonymous with miscarriage, with miscarriage being the preferred patient-facing term 3
Clinical Context for Two Mid-Trimester Losses
While the classical definition requires three losses, two mid-trimester spontaneous abortions represents a clinically significant pattern that warrants investigation:
- Second-trimester losses (after the first trimester) are particularly significant risk factors for subsequent pregnancy loss 4
- Women who experience loss after the first trimester have odds ratios ranging from 1.4 to 5.6 for being a "repeater" (experiencing recurrent losses), depending on associated characteristics 4
- Loss of a chromosomally normal conception in the second trimester is a specific risk factor for recurrent spontaneous abortion 4
Important Clinical Distinctions
Mid-trimester losses carry different implications than first-trimester losses:
- Fetal loss occurs predominantly in the first trimester in most pregnancy series 3
- Second and third trimester losses have distinct etiologies and higher rates of complications in certain conditions 3
- Second-trimester abortion (13 or more weeks' gestation) represents approximately 10% of all abortions in the United States 5
Risk Stratification
After two mid-trimester losses, specific risk factors should be evaluated:
- Cervical incompetence diagnosis 4
- History of very low birthweight deliveries 4
- Chromosomal abnormalities (causative in approximately 50% of spontaneous abortions overall) 6
- Anatomical, endocrine, immunologic, and thrombophilic factors 1, 2
The term used depends on clinical context: while "recurrent spontaneous abortion" traditionally requires three losses, two mid-trimester losses warrant the same comprehensive evaluation given their prognostic significance.