AbstractObjectivesWe have investigated the efficacy of using quantitative fluorescent polymerase chain reaction (QF‐PCR) for the prenatal recognition of aneuploidy in chromosomes 13, 18, 21, X and Y. A total of 1115 samples, from mainly southeast Asian patients, were analysed and compared in a blind trial to the results previously obtained cytogenetically.MethodsA multiplex PCR involving 15 short tandem repeat (STR) sequences was used. The probability of two or more of these markers being informative was calculated, and this required the multiplex PCR to be modified.ResultsThe QF‐PCR and previous cytogenetic results concurred, except for two products of conception (POC). One of these may be a case of complete uniparental disomy that was not recognized cytogenetically. The other was tetraploid, and as such appeared normal using QF‐PCR. A mosaic trisomy 18 was correctly identified. The population sample was of a mainly Chinese, ethnic origin, and the allele frequency, size and heterozygosity appeared more restricted than the population groups analysed hitherto.ConclusionThe QF‐PCR methodology is an efficient cost‐effective method of screening for major chromosome aneuploidy, and, for certain referral categories, could be used alone. It also appears to be applicable to patients of different ethnic origins. Copyright © 2004 John Wiley & Sons, Ltd.