Chickenpox virus, which is a virus that has been known to cause malformations in early pregnancy, is the most sensitive stage of infection throughout pregnancy. However, the teratogenicity of rubella virus, for example, is much lower when compared to other viruses that we tend to cause risk. In this regard, there is no good way to further test for this, because sometimes the fetal malformations are not specific, so it is difficult to give a very definite answer whether the child is affected or not. As long as we attend regular pregnancy care, such as ultrasound for malformation screening at about 20 weeks and ultrasound for fetal monitoring from 24 to 28 weeks, we should perform systematic screening, and if there is no indication of significant developmental abnormalities or birth defects in the child, we can observe it closely, rather than we give make other recommendations without any evidence.