Ta. Cowles et al., A PROSPECTIVE CYTOGENETIC STUDY IN 3RD-TRIMESTER PLACENTAS OF FETUSESWITH UNEXPLAINED INTRAUTERINE GROWTH RESTRICTION, Journal of maternal-fetal investigation, 6(4), 1996, pp. 207-209
Objective: The purpose of this study was to see if chromosomal mosaici
sm confined to the placenta was more frequently found in pregnancies c
omplicated by intrauterine growth restriction. Methods: Placentas from
20 pregnancies resulting in appropriately grown term infants and 20 p
regnancies complicated by unexplained fetal growth restriction were pr
ospectively identified. Placental tissue culture and cytogenetic analy
sis were performed to evaluate chromosomal mosaicism confined to the p
lacenta. Results: One of the placentas from the group of growth-restri
cted infants demonstrated a high level of mosaicism for tetraploidy (4
6,XX/92,XXXX). Normal placental karyotypes were found in the control g
roup. Conclusion: It is suggested that mosaic abnormalities confined t
o the placenta, unrelated to culture artifact or fetal karyotype, may
occur more frequently than is currently recognized. Further studies ma
y reveal whether tetraploidy is a nonrandom abnormality.