Do people with risky behaviours participate in biomedical cohort studies?
People with risky behaviours participated in this health study in the same proportions as people without these risk factors.
High-resolution ultrasonography was more accurate than AF biochemistry in the detection of congenital anomalies associated with elevated AFP levels and acetylcholinesterase in the AF. Routine measurement of these biochemical markers in AF samples obtained for cytogenetic analysis appears to have a very low yield and would therefore not be cost-effective in practices where high-resolution ultrasonography is performed before amniocentesis.