Karyotype of amniotic fluid cells at the AUB-MC results on 2000 cases.

We report results on 2000 cases of amniotic fluid referred for karyotype analysis. Referrals were advanced maternal age in 64% of cases and abnormal ultrasound in 12% of cases. The frequency of chromosome aneuploidy was 2.4% in the first category and that of chromosome abnormalities 8% in the second. The incidence of marker chromosomes was 0.25%, that of mosaicism 0.3%, and maternal cell contamination was observed in 0.6% of cases. The overall culture failure rate was 0.9%. Our results are mostly in accordance with figures from larger surveys, published in the literature and differences might be due to the smaller number of samples in this series and variation in referral and/or sampling protocols.