Human Cytomegalovirus (HCMV) Shedding and T-cell Immune Responses in HCMV-seropositive Women During Pregnancy and Postpartum: Prevalence, Natural History, and Risk Factors

BACKGROUND: Human cytomegalovirus (HCMV) during pregnancy and poor immune control of HCMV are associated with adverse outcomes. Limited data exist on the prevalence, natural history, and risk factors of HCMV shedding and T-cell immune responses during pregnancy and postpartum in HCMV-seropositive women. METHODS: Samples from 160 HCMV-seropositive women were collected at 3 time points during pregnancy and once postpartum. Shedding was determined by detecting HCMV DNA in saliva, urine, and vaginal secretions by quantitative polymerase chain reaction. HCMV-specific T-cell immune responses were determined by detecting interferon-gamma released in blood by QuantiFERON-CMV and T-SPOT.CMV assays. Information on demographics and contact with children's bodily fluids was collected. RESULTS: The prevalence of HCMV shedding in HCMV-seropositive women in any bodily fluids was 18.8% [95% CI: 13.0-25.7%] during pregnancy and 21.3% [95% CI: 15.2-28.4%] including postpartum. Ethnicity [OR 0.2, 95% CI: 0.05-0.95, P = .043] and gravidity [OR 0.2, 95% CI: 0.05-0.94, P = .042] were associated with detection of shedding. Shedding quantity was associated with contact with children's saliva [Incidence rate ratio 1.98, 95% CI: 1.69-2.33, P < .001]. The prevalence of T-cell immune responses was ≤75% and almost 100% using QuantiFERON-CMV and T-SPOT.CMV, respectively. T-cell immune responses did not correlate with shedding. CONCLUSIONS: Around 1 in 5 HCMV-seropositive women shed HCMV during pregnancy and postpartum. Ethnicity and gravidity are associated with shedding, but not T-cell immune responses, and the quantity of shedding is associated with contact with saliva. Further studies investigating HCMV shedding, immune responses and their risk factors in women during pregnancy and postpartum are warranted.