First-trimester placental volume as a marker for chromosomal anomalies: preliminary results from an unselected population.
OBJECTIVE
To compare first-trimester placental volume in chromosomally abnormal and normal pregnancies.


METHODS
Placental volumes were routinely recorded at the time of nuchal translucency thickness measurement at 10-13 weeks of gestation. This was done using customized three-dimensional ultrasound equipment and measurements were then converted to the placental quotient (placental volume/fetal crown-rump length). The possible difference in placental quotient between chromosomally normal and abnormal pregnancies was examined.


RESULTS
A total of 2863 pregnancies was evaluated, including 17 with major chromosomal defects (nine cases of trisomy 21, four of trisomy 18, two of trisomy 13, and one each of Turner syndrome and 48,XXY + 21). The median placental quotient in the chromosomally abnormal group (0.67) was significantly lower than that in the normal fetuses (0.98). In nine of the 17 affected pregnancies the quotient was below the 10th centile of the normal range.


CONCLUSIONS
Assessment of placental volume may prove to be useful in first-trimester risk assessment for chromosomal anomalies.
Metzenbauer
M
M
Ludwig-Boltzmann Institute for Clinical Obstetrics and Gynaecology, Department of Obstetrics and Gynaecology, Donauspital Vienna, Vienna, Austria. martin.metzenbauer@smz.magwien.gv.at
Hafner
E
E
Schuchter
K
K
Philipp
K
K
D000293:Adolescent; D000328:Adult; D002882:Chromosomes, Human, Pair 13; D002887:Chromosomes, Human, Pair 18; D015331:Cohort Studies; D004314:Down Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D005819:Genetic Markers; D006801:Humans; D008875:Middle Aged; D010920:Placenta / Q000000981:diagnostic imaging; D010927:Placental Insufficiency / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011295:Prenatal Care; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D014314:Trisomy / Q000175:diagnosis*; D016216:Ultrasonography, Prenatal
D005819:Genetic Markers