Maternal age-specific fetal loss rates in Down syndrome pregnancies.
Level 3 - non-randomized controlled study
Observational follow-up cohort study with survival analysis
PubMed 16634111 · doi:10.1002/pd.1443
What was done
Estimated maternal age-specific spontaneous fetal loss rates in Down syndrome (DS) pregnancies using survival analysis on follow-up data from 5,177 prenatally diagnosed cases. The maternal age effect was subsequently evaluated by re-analyzing published comparisons of maternal age-specific DS prevalence at different gestational ages.
What was found
The average fetal loss rate between chorionic villus sampling (CVS) and term was 32% (95% CI: 26–38%), increasing from 23% (95% CI: 16–31%) for women aged 25 to 44% (95% CI: 33–56%) for women aged 45. Between amniocentesis and term, the average loss rate was 25% (95% CI: 21–31%), increasing from 19% (95% CI: 14–27%) at age 25 to 33% (95% CI: 26–45%) at age 45.
Why it matters
Quantifying how maternal age influences spontaneous loss in DS pregnancies is critical for accurately adjusting baseline risk models, calculating prenatal screening performance metrics, and estimating live birth prevalence in populations where prenatal diagnosis and termination occur.
Limits
The abstract does not specify cohort setting/geography, does not report whether losses were separated from procedure-related loss risks, and lacks information on potential confounders such as specific structural fetal anomalies.
Cited by
- supports Fetuses and pregnancies with Down syndrome face a significantly higher risk of miscarriage or stillbirth.