The utilisation of nuchal translucency as a prenatal marker of Down syndrome, 1993-1999.
A sample of 6,038 obstetric ultrasound referrals and reports between January 1993 and June 1999 in a single Melbourne private ultrasound practice was reviewed to determine whether the referral and reporting pattern for nuchal translucency (NT) measurement has changed. The proportion of both 10-14 week ultrasound scans and mid trimester fetal anatomy scan referrals increased significantly over the study period (p < 0.001 and p < 0.001, respectively). There was also a significant increase in NT reporting and the number of specific referrals for an NT measurement over the study period (p = 0.01 and p < 0.001, respectively). If current trends continue it is likely that the 10-14 week scan for NT measurement will become a routine component of antenatal care. Therefore, as a matter of urgency, it is imperative that the best and most cost-effective screening strategy for Down syndrome in an Australian population is defined.