A pregnant woman at 10 weeks gestation is confirmed to have acute CMV primary infection by serology (IgM positive, IgG positive, low IgG avidity index). She is counselled that the risk of vertical transmission and fetal damage is highest at:

• A First trimester primary CMV infection ✓
• B Third trimester primary CMV infection
• C Reactivation CMV infection regardless of trimester
• D Second trimester primary CMV infection

Explanation

First-trimester primary CMV infection carries the highest risk of symptomatic congenital disease (sensorineural hearing loss, chorioretinitis, microcephaly, periventricular calcifications) and neurological sequelae because organogenesis and CNS development are ongoing; although transmission rate is lower in the first trimester, the consequences are most severe. Third-trimester transmission is more frequent but usually causes asymptomatic or mildly symptomatic infection. CMV reactivation carries a much lower risk of severe congenital disease compared to primary infection.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.