Patient: Description (main symptoms, onset) The test was performed on March 12, 2010, when I was 18 weeks + 5 days pregnant, and the test result was positive for rubella virus RUV-IgM, and I have not had any symptoms so far. How much risk is there after the ultrasound to rule out malformations? Can a 4D ultrasound completely rule out the risk of malformation? Do I need to go to another hospital for a new blood test? Test results: Rubella virus RUV-IgM positive. Doctor: Hi, rubella infection is generally mild for adults, but fetal infection can be extremely serious. Congenital rubella syndrome (CRS) may manifest as transient abnormalities, including purpura, splenomegaly, jaundice, meningitis, thrombocytopenia, or as permanent disorders such as cataracts, glaucoma, heart disease, deafness, microcephaly, and mental retardation. In addition, distant complications may include diabetes mellitus, thyroid abnormalities, precocious puberty, and progressive rubella holoprosencephalitis. Forty CRS survivors from 1939-1943 were followed for up to 50 years, and all were found to have hearing impairment and 23 had combined ocular defects associated with rubella infection. It was found that the incidence of fetal infection was highest at 11 weeks of gestation and that the incidence of congenital defects was highest in early gestation (90%) and declined progressively in mid- to late gestation. The diagnosis of intrauterine fetal infection is difficult and is made by testing for rubella-specific IgM antibodies in fetal blood specimens and by isolating the virus from amniotic fluid and pregnancy products (to my knowledge, not many hospitals in China perform this test). There is no effective treatment for rubella virus infection and termination of pregnancy is the only effective treatment. (The above is excerpted and compiled from High Risk Pregnancy, Chapter 30, and is reproduced with attribution). In your case, you are now 18 weeks pregnant, the acute stage of infection, receding from the incubation period of 2-3 weeks, the risk of intrauterine infection in the fetus is still relatively high. You can determine the approximate time of infection according to the time of appearance of your symptoms (fever, joint pain, swollen lymph nodes behind the ear, etc.) and decide whether to continue the pregnancy according to your pregnancy wishes.