Objective: To evaluate whether chromosomal microarray (CMA) should be offered to fetuses with ultrasonographic soft markers (USMs) in the second trimester. Methods: A prospective cohort study and meta-analysis were conducted. In the prospective cohort study, 564 fetuses with USMs were enrolled. In the meta-analysis, eligible articles describing copy number variations in fetuses with USMs were included. Results: In the prospective cohort study, the diagnostic yields of CMA over noninvasive prenatal testing (NIPT) and karyotyping were significantly higher in fetuses with mild ventriculomegaly (MVM) than those in local control cohorts with normal ultrasound. However, the yields of CMA over NIPT and karyotyping in fetuses with other USMs were similar to controls. About ten studies, involving 405 fetuses with MVM and 1412 fetuses with other USMs, were included in the meta-analysis. The pooled diagnostic yields of CMA over NIPT and karyotyping in fetuses with MVM were 4.9% and 3.2%, respectively. In fetuses with other USMs, the yields of CMA over NIPT and karyotyping were 1.2% and 0.4%, respectively. Conclusion: It is reasonable to offer CMA as a first-tier test to fetuses with MVM. However, for fetuses with other USMs, the considerations to perform CMA should not differ from pregnancies with normal ultrasound. 1 | INTRODUCTION Ultrasound has become a crucial tool for the prenatal evaluation of growth and anatomy worldwide. 1 In China, a routine prenatal ultrasound is performed at 18 to 24 weeks gestational age for the detection of fetal anomalies and pregnancy complications and the majority of women choose to participate. 2 In addition to fetal structural abnormalities or abnormal fetal development, many other nonspecific, often transient anatomic findings, also known as "soft markers," can also be detected. 3,4 Although these soft markers are not anatomic abnormalities, there is evidence that they convey a statistically increased risk for fetal aneuploidy. 3,5 When ultrasonographic soft markers (USMs) are detected in second trimester, the finding can raise questions about prenatal diagnostic testing procedures. As technologies evolve, various methods are currently implemented in prenatal genetic testing, including noninvasive prenatal testing (NIPT) and invasive testing using karyotyping or chromosomal microarray (CMA). As compared to invasive testing, NIPT using cell-free fetal DNA (cffDNA) from maternal plasma is noninvasive and more acceptable by women. In contrast, invasive prenatal testing is performed by chorionic villi sampling, amniocentesis, or cord blood sampling, which is associated with an increased risk of miscarriage and other side-effects. 6 Karyotyping using the cells obtained from invasive testing is the conventional cytogenetic test with a