Second-trimester maternal serum analyte levels associated with fetal trisomy 13

The aim of this study was to determine whether pregnancies affected by feta l trisomy 13 are associated with second-trimester maternal serum analyte le vels different from those typical of the unaffected population. Pregnancies with trisomy 13 were identified through cytogenetics laboratories. Those w hich had second-trimester maternal serum screening analyte measurements wer e further evaluated. Maternal serum analyte levels for each case and five m atched controls were statistically analysed by matched ranked-sum analysis. 28 cases of fetal trisomy 13 were identified. The median AFP, uE3 and hCG levels were 1.35 MoM, 0.71 MoM and 0.90 MoM, respectively. Only uE3 levels were statistically different (p<0.01) from those for the unaffected populat ion. These data suggest that second-trimester maternal serum AFP, uE3 and h CG levels are not useful in detecting fetal trisomy 13 and protocols alread y existing for Down syndrome or trisomy 18 screening will not detect the ma jority of cases of this aneuploidy. Copyright (C) 1999 John Wiley & Sons, L td.