Physical and Intellectual Development in Children with Asymptomatic Congenital Cytomegalovirus Infection: a Longitudinal Cohort Study in Qinba Mountain Area, China

Background: Although about 90% of congenital cytomegalovirus (CMV) infection is asymptomatic in newborn, some of them could show sequelae later in life. Qinba mountain area is a place with high incidence of mental retardation and a high rate of CMV intrauterine transmission in China. The correlation between asymptomatic congenital CMV infection and developmental outcomes of children in this area remain unclear.

Objectives: To investigate the impact of asymptomatic congenital CMV infection on physical and intellectual development of children during the first 6 years of life in Qinba mountain area.

Study Design: Longitudinal cohort study. Forty-nine of all the 54 children with asymptomatic congenital CMV infection were followed prospectively in a study for surveying physical growth and intellectual developments.

Results: Either in neonatal or in infant period, no significant difference was noted between the asymptomatic congenital CMV infection children and the controls in average weight, height and head circumference (both p>0.05). The intellectual development was disproportion in asymptomatic congenital infected children. Compared with the control group, both global development quotient (DQ) and full-scale intelligence quotient (IQ) scores of asymptomatically infected children were worse (t=2.19, p=0.031; t=2.48, p=0.015), especially on language DQ scores (t=3.25, p=0.002) and verbal IQ scores (t=3.88, p=0.000). However, the incidence rates of mental retardation (DQ/IQ<70) were similar in two groups (chi(2)=1.03, p>0.05).

Conclusions: Although asymptomatic congenital CMV infection did not have significant influence on the neonatal physical development or incidence of mental retardation later in life, it is obviously an important factor correlating with long-time cognitive outcomes, especially on the development of language. It is necessary to survey CMV congenital infection and monitor the early intellectual development of children with asymptomatic congenital CMV infection in this area.