Quantifying the burden of congenital CMV infection (cCMV) with long-term sequelae in subsequent pregnancies of women seronegative at their first pregnancy.

BACKGROUND In women seronegative before pregnancy, cCMV related sequelae are exclusively seen in those infected in the first trimester of pregnancy. Up to 30% of infected neonates following maternal primary infection in the first trimester suffer long-term sequelae. Maternal parity is an established risk factor of cCMV in previously seronegative women. OBJECTIVE to quantify the risk of cCMV and related sequelae following primary infection in the first trimester in subsequent pregnancies in a population of women seronegative at their first pregnancy. METHODS 739 women seronegative at their first pregnancy had at least one of 971 subsequent pregnancies and deliveries managed at our institution. All women had CMV IgG and IgM testing at 11-14 weeks' of each pregnancy. RESULTS 15.6% (115/739) of women seroconverted between 2 consecutive pregnancies. 29% (33/115) of seroconversions occurred in the periconceptional period or in the first trimester. The risks for cCMV and related sequelae (neurologic and/or hearing loss) following maternal infection in the first trimester were respectively 24 and 6-fold higher (RR [95%CI] =24 [10.8-62.3] and 6 [1.5-24]) than the general pregnant population. 88% (29/33) and 92% (11/12) of, respectively, all primary maternal infections and fetal infections in the 1st trimester occurred when the inter-pregnancy interval was ≤2 years. CONCLUSION Women seronegative at their first pregnancy with a subsequent pregnancy within 2 years have the highest risk of delivering a child with cCMV-related sequelae. These women should be made aware of the risk and given the opportunity of serology screening in the first trimester.