Early Asymmetric IUGR and Aneuploidy

Abstract

OBJECTIVE: To determine the incidence of chromosomal abnormalities in fetuses with asymmetric growth retardation in the second and early third trimesters of pregnancy. METHODS: From November 1989 to December 1993, 71 singleton pregnancies with asymmetrical growth retardation diagnosed at 15 to 35 weeks gestation had detailed ultrasonographic examination for structural malformations and fetal karyotyping done. RESULTS: The fetal karyotype was abnormal in 7 (9.9%) of the cases. There were 19 growth retarded fetuses with concomitant structural defects. The incidence of chromosomal abnormalities in asymmetrical growth retarded fetuses with structural defects was 21% (4/19). The incidence of fetal aneuploidy in structurally normal fetuses with asymmetrical growth retardation detected before 23 weeks gestation was 20% (3/15); while for those presenting between 23-29 weeks gestation, no abnormal karyotypes were found. CONCLUSION: Although more prospective data is needed, our data seems to suggest that fetal karyotyping may be unnecessary in structurally normal fetuses with early onset intrauterine growth retardation occurring between 23-29 weeks of gestation.