Risk for chromosomal aberrations in apparently isolated intrauterine growth restriction: A systematic review

Objective To perform a systematic review examining the risk of chromosomal aberrations in apparently isolated intra-uterine growth restriction (IUGR). Methods Search was conducted by research librarian in five databases. By independent screening of 2894 references, two investigators selected original studies examining the risk of chromosomal aberrations in apparently isolated IUGR diagnosed at the second and third trimesters using ultrasound. We excluded studies describing IUGR combined with additional fetal anomalies detected by ultrasound and those where fetuses with structural anomalies or aneuploidy were not reported. Results Fourteen observational cohort studies were found, encompassing 874 apparently isolated IUGR cases. Mean rate of chromosomal aberrations was 6.4%, ranging between 0% (in three studies) to 26.3%. Only two articles examined apparently isolated IUGR diagnosed in third trimester, encompassing a total of 32 pregnancies. Invasive testing of these cases yielded normal karyotypes. A single article analyzed 137 second trimester IUGR pregnancies, reporting two abnormal karyotypes of minimal clinical significance. Overall quality of existing evidence was defined as "very low". Conclusions Due to a limited number of cases and insufficient quality of evidence, high-quality well standardized case-controlled trials should be conducted, further exploring the risk for chromosomal aberrations in pregnancies with isolated IUGR.