Table 3 Effectiveness of preventive interventions

Adler et al. (2004) [52]

Recruitment and attrition: 42 out of 234 enrolled women were excluded as HCMV seropositive at enrolment and 26 failed to provide the follow-up specimens.

Treatment adherence: Although there was no association between adherence measures and infection rates, it seems that intervention was more successful in pregnant women than in non-pregnant women as they were more committed to behavior modification. For example, women who were pregnant at the time of registration reported kissing their child on the lips half as often as women who were not pregnant. In addition, these objective and subjective measures may not have reflected actual practice.

Control group: 7.8% seroconverted; Intervention group: 7.8% (P = 1). There was a significant association between maternal infection and children excreting HCMV at any time and attempted pregnancy at enrolment. In addition, not being pregnant at enrolment significantly increased risk of acquisition (P < 0.0001). Pregnant: 5.9% Attempting pregnancy: 41.7%; P = 0.008

Prenatal counselling for HCMV infection in pregnant women at the first obstetric visit may reduce the risk of HCMV infection. Behavioral intervention as preventive measure for seropositive pregnant women with young children in day care may have broad public health impact.

Picone et al. (2009) [50]

Recruitment and attrition: Of the 4,287 pregnant women at baseline, 495 were already HCMV seropositive before the first visit to the center. Of the remaining 3,792, 127 refused screening.

The infection rate between 12–36 WG was significantly lower (0.01% pregnant woman-week) than the infection rate before 12 WG (0.04% pregnant woman-week) (mid P = 0.02, 95% CI [1.07–13.6]). HCMV-seroconversion: 0–12 WG: 0.46% of pregnant women, 12–36 WG: 0.26% of pregnant women (CI: 1.07–13.6; mid P = 0.02, 95%).

Of the 5 women who seroconverted between 12–36 WG, 2 of the newborns were infected but asymptomatic. Among the nine women with primary infection, there were two spontaneous fetal losses and one infected baby who had petechiae at birth and unilateral hearing loss at 1-year of age.

Information on prevention and hygiene has a positive impact and could significantly reduce the incidence of maternal HCMV infection during pregnancy.

Vauloup-Fellous et al. (2009) [51]

Recruitment and attrition: From 5312 pregnant women who had unknown immune status or were known to be HCMV seronegative, 127 refused HCMV screening.

The infection rate between 12–36 WG was 0.008% per pregnant woman-week, and was significantly lower than the infection rate before 12 WG, which was 0.035% per pregnant woman-week (mid P = 0.005). HCMV-seroconversion: 0–12 WG: 0.42% of pregnant women, 12–36 WG: 0.19% of pregnant women (P < 0.005).

Of the 5 women who seroconverted between 12–36 WG, 2 of the newborns were infected but asymptomatic. Among the 11 mothers with primary infection, there were two spontaneous fetal losses and one infected baby who had petechiae at birth and unilateral hearing loss at 1-year of age.

Easy-to-follow information on basic hygienic measures, mainly related to the handling of young children, at the beginning of pregnancy could significantly reduce the incidence of maternal HCMV infection during pregnancy and thus the number of infected fetuses.

Reichman et al. (2014) [48]

Recruitment and attrition: 56 out of 500 women planning pregnancy, who attended to the fertility clinic, discontinued attending the clinic.

Most women were seropositive (79.7%), 16.2% were seronegative and 4.1% (2.7% remote infection and 1.4% primary infection) were found to have evidence of seroconversion at the time of initial screening. Women who were seronegative did not show seroconversion during the year following the start of screening.

Cytomegalovirus testing and counselling at preconception seemed effective in reducing HCMV exposure in pregnancy.

Revello et al. (2015) [49]

Recruitment and attrition: Of the 4096 women in the intervention group assessed for eligibility, 1235 had risk factors. Overall, 745 were enrolled and tested for HCMV antibody and 477 were excluded as IgM-HCMV seropositive. In addition, 13 women declined to participate. Of the 745 women who were enrolled and tested for HCMV IgG and IgM, 343 had IgG +, IgM – and were no further tested. Of the total, 331 women were considered and tested at birth.

In the control group, of the 4732 women assessed for eligibility, 1798 had risk factors. Of these, 1265 were excluded (IgG positive, awareness of HCMV, absence of screening for fetal aneuploidy at 11–12 week’s gestation, declined to participate). Of the 553 women who were enrolled and test for HCMV IgG and IgM, 315 were re-tested.

Treatment adherence: 93% of women reported hygiene recommendations were worth suggesting to all pregnant women at risk for infection. 80% of the women reported substantial or complete compliance with the suggested recommendations.

The seroconversion rate in the intervention group (1.2%) was significantly lower than in the control (7.6%) group (Δ = 6.4%, 95% CI 3.2–9.6; P < 0.001). 3 newborns with congenital infection were in the intervention group and 8 in the control group (1 with cerebral ultrasound abnormalities at birth).

Identification and hygiene counselling of HCMV seronegative pregnant women may represent a responsible and acceptable prevention strategy to reduce primary maternal infection and thus congenital HCMV infection. However, a positive attitude is needed in women as the hygiene recommendations implied substantial and continuous behavioral changes.

Calvert et al. (2021) [53]

Recruitment and attrition: Of the 3975 of pregnant women, 3097 were not eligible (88.8% not living with a child aged less than four), 13 no blood sample was obtained, 483 were HCMV seropositive and 269 were not recruited. Of the 103 women that agree to participate in the RCT, only 87 participants completed the study.

After intervention, knowledge about HCMV was significantly different between participants in the intervention group and participants in the treatment as usual group. Within the treatment group there were significant differences at baseline compared to the 34 WG on how HCMV is transmitted and the possible consequences of congenital CMV for the child. However, in the control group, there were no significant differences in knowledge of how HCMV is transmitted.

In addition, women in the intervention group reported less frequent risky activities (kissing children on the lips, eating leftover food) compared to the usual treatment group.

No different scores on anxiety and depression were observed between the intervention and treatment as usual groups at baseline or at 34 weeks.

Seroconversion in pregnant women in the intervention group was 4.55% and, in the treatment, as usual group was 4.65%

Digital antenatal HCMV education is accessible and acceptable to pregnant women and they are willing to adopt behavioral change to reduce their risk of HCMV infection.