Maternal IgG avidity, IgM and ultrasound abnormalities: combined method to detect congenital cytomegalovirus infection with sequelae

Abstract

We used maternal immunoglobulin M (IgM), immunoglobulin G (IgG) avidity index (AI) and fetal ultrasonography (US) to effectively detect a congenital cytomegalovirus-infected fetus that would suffer neurological sequelae after birth. The detecting method was prospectively adapted to 1163 unselected pregnant women. IgM, IgG and IgG-AI were measured at the first prenatal examination (10.8±2.2 weeks of gestation). Advanced US was performed for the IgM-positive women at our center. The urine of 1163 neonates was examined via PCR. All infected neonates were followed for neurological development. Most women (83.3%) were seropositive. Among them, 40 (4.1%) were IgM positive. Nine of forty (22.5%) had low AI, of which one showed abnormal US and suffered severe sequelae. The remaining eight had a normal US; however, one infant had hearing impairment. There were another three infected infants with normal development. Their mothers' serological results were: IgM positive with high AI (n=1); IgG positive; IgM negative with high AI (n=1); and both IgG and IgM negative (n=1). This method enabled us to detect infected fetuses having severe sequelae. However, the problem remains of detecting infected fetuses that only have a hearing impairment.