Maternal serum analyte levels in pregnancies with fetal Down syndrome resulting from translocations.
OBJECTIVE
Our purpose was to determine whether pregnancies affected by fetal Down syndrome resulting from Robertsonian translocations are associated with second-trimester maternal serum analyte levels different from those resulting from fetal trisomy 21.


METHODS
Pregnancies with Down syndrome caused by Robertsonian translocations were identified through the cytogenetics laboratories at the participating institutions. Those with maternal serum screening values between 15 and 20 weeks were evaluated.


RESULTS
Eleven cases of fetal Down syndrome caused by Robertsonian translocations were identified. The median alpha-fetoprotein, unconjugated estriol, and human chorionic gonadotropin levels were 0.68, 0.67, and 2.83 multiples of the median, respectively. These analyte levels are similar to those for fetal trisomy 21.


CONCLUSIONS
These data suggest that Down syndrome resulting from either Robertsonian translocations or trisomy 21 will be detected in a similar percentage of cases because the second-trimester maternal serum analyte levels are similar.
Saller
D N
DN
Department of Obstetrics and Gynecology, Strong Memorial Hospital, University of Rochester School of Medicine and Dentistry, NY 14642, USA.
Canick
J A
JA
Kellner
L H
LH
Rose
N C
NC
Garza
J
J
French
C A
CA
Mooney
R A
RA
D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood*; D002883:Chromosomes, Human, Pair 14; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000097:blood* / Q000235:genetics*; D004964:Estriol / Q000097:blood*; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D014178:Translocation, Genetic; D000509:alpha-Fetoproteins / Q000032:analysis*
D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins; D004964:Estriol