A large
inpatient-based study in the United States estimated
the odds ratio for stillbirth to be 1.28 (95% confidence
interval [CI], 1.24 –1.32) in women aged 35–39 years
and 1.72 (95% CI, 1.6 –1.81) in women aged 40 years
or older compared with 20 –34-year-old women.15