Fetal loss in Down syndrome pregnancies.
Level 3 - non-randomized controlled study
Meta-analysis and synthesis of national registry and observational cohort studies
What was done
The authors analyzed spontaneous fetal loss data in Down syndrome pregnancies recorded in the National Down Syndrome Cytogenetic Register between 1989 and 1996. They combined these data with published results from other studies in a meta-analysis, excluding one study due to incorrect methodology.
What was found
Based on the combined data, 43 percent (95 percent CI: 31-54 percent) of pregnancies ended in miscarriage or stillbirth between chorionic villus sampling and term. Between amniocentesis and term, 23 percent (95 percent CI: 19-28 percent) ended in miscarriage or stillbirth. Among births, 12 percent (95 percent CI: 2-23 percent) were stillborn or resulted in neonatal death.
Why it matters
Quantifying gestational-age-specific fetal loss rates prevents the overestimation of detection rates when evaluating early antenatal screening and diagnostic testing programmes.
Limits
The abstract does not report the total number of pregnancies or the number of included studies. As an observational synthesis, it is subject to confounding from procedure-related losses versus natural demise and potential selection bias between women undergoing different diagnostic procedures.
Cited by
- supports Fetuses and pregnancies with Down syndrome face a significantly higher risk of miscarriage or stillbirth.