Should I terminate my pregnancy in case of a rubella infection?

Hello doctor,

I am 18 weeks pregnant. When I was 16 weeks and 5 days pregnant, a few red rashes appeared on my face and I felt a little sick. On the next day, it spread to my hands and the upper part of the body along with a minor fever. So, I went to my gynecologist who referred me to a physician. I was asked to test for measles and rubella and the result was positive for rubella. The lab result read Rubella-IgM-Grayzone (1.23). The rashes faded on the next day and completely vanished one day later. The fever and the body pain went away with the rashes. However, I had minor joint pains until two days later. My gynecologist asked me to repeat the test and I did the second test when I was at 17 weeks and 3 days, and the result came positive for rubella IgM as 15.18. She asked me to terminate the pregnancy immediately. Could you please advise what would be the next step at this stage? Can a defect, if any, not be identified with a scan?