Obstetrician-gynecologists Performing Genetic Amniocentesis May Be Misleading Themselves and Their Patients

Objective: Our purpose was to compare midtrimester amniocentesis-related fetal loss rates between obstetrician-gynecologists and perinatologists.

Study Design: This cohort study analyzes 1384 midtrimester amniocenteses from January 1, 1996, to December 31, 1999. Obstetrician-gynecologists who split their practices between two or more hospitals and explained fetal losses (eg, fetal anomalies, aneuploidy) were excluded from analysis. Eight obstetrician-gynecologists performed 138 procedures; 3 perinatologists performed 1246 procedures. Three experienced obstetrician-gynecologists accounted for 113 procedures. Analysis was by chi2.

Results: Within 30 days of midtrimester amniocentesis, there were 3 fetal losses for obstetrician-gynecologists and 4 for perinatologists (P =.02, chi2 = 5.19, degrees of freedom = 1). Obstetrician-gynecologist loss rates were 1 in 46 procedures versus 1 in 312 procedures for perinatologists. Losses were clustered among the 3 experienced obstetrician-gynecologists (P <.01, chi2 = 6.93, degrees of freedom = 1). The experienced obstetrician-gynecologist fetal loss rate was 1 in 38 amniocenteses, and the perinatologist fetal loss rate was 1 in 312.

Conclusion: The risk of fetal loss from midtrimester amniocentesis appears to be higher when performed by an obstetrician-gynecologist compared with a perinatologist.