Management of Cytomegalovirus Seroconversion during Pregnancy in France

[Implementation of screening for cytomegalovirus congenital infection in a French type 3 maternity]

OBJECTIVES

Congenital cytomegalovirus (CMV) infection is the most common congenital infection and the leading cause of infectious neurosensorial disability in newborns. We wanted to organize the management of women from the beginning of pregnancy allowing access to antenatal treatment with valaciclovir, recognized since 2020 as limiting materno-fetal transmission. To this end, we set up and evaluated the interest of systematic screening for CMV infection in our maternity. We wanted to organize care for women from the very start of pregnancy.

METHODS

Retrospective and comparative descriptive study carried out at the CHRU de Limoges from July 2017 to December 2019 (targeted screening), then from January 2020 to June 2022, during which period we implemented systematized screening by iterative serologies at the 3rd, 6th, 8th months and before delivery. Our main evaluation criteria were the seroprevalence of CMV infection and the rate of congenital infection. We then described our cases of infection (primary or secondary) during pregnancy.

RESULTS

CMV seroprevalence in our pregnant women increased significantly from 52.7% (779/1478 women screened) to 58.4% (3852/6599 women screened) between the 2 study periods (P=0.04). We diagnosed 11 infections during the first part of the study vs. 27 during the second, with a significant increase in primary infections from 0.14% (9/6524 births) to 0.37% (24/6426 births) (P=0.008). Only 3 secondary infections were diagnosed during the second study period. The rate of congenital infections remained stable between the 2 study periods (6 children/6524=0.09% vs. 8 children/6426=0.12%; P=0.57).

CONCLUSION

Our results confirmed the interest of screening for CMV infection, while modifying the screening strategy we had initiated.

Contribution of fetal blood sampling to determining the prognosis of congenital cytomegalovirus infections: a case-cohort study in Switzerland

BACKGROUND

Cytomegalovirus is responsible for the most common congenital infection, affecting 0.5% to 1.0% of live births in Europe. Congenital cytomegalovirus infection can be diagnosed during pregnancy by viral DNA amplification in the amniotic fluid, but the prognosis of fetuses without severe brain abnormalities remains difficult to establish on the basis of prenatal imaging alone.

OBJECTIVE

To identify predictors of moderate to severe symptomatic cytomegalovirus infection among fetal blood parameters and to propose an algorithm on the basis of these parameters and on prenatal imaging that would provide the best positive and negative predictive values.

STUDY DESIGN

Fetal blood sampling at 21-28 weeks gestation was performed in fetuses with congenital cytomegalovirus infection confirmed by amniocentesis after maternal infection in the first-trimester or periconceptional period. We compared the levels of hemoglobin, thrombocytes, γ-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, β2-microglobulin, immunoglobulins G and M, and cytomegalovirus DNA viral loads in amniotic fluid and fetal blood between those with moderate to severe symptomatic infection and those with asymptomatic to mild infection (median follow-up of 36 months for live births).

RESULTS

Among 58 fetuses included, 25 (43%) had a moderate to severe symptomatic infection: 16 with severe cerebral abnormalities, 5 with multiple signs or symptoms at birth, 2 with bilateral sensorineural hearing loss, and 2 with neurodevelopmental delay. The values of thrombocytes, aspartate aminotransferase, β2 microglobulin, Immunoglobulin M, and cytomegalovirus viral loads differed significantly between fetuses with moderate to severe symptomatic infection and those with asymptomatic to mild infection. The optimal strategy to predict moderate to severe symptomatic infection was to first perform fetal brain imaging, followed by fetal blood sampling with the following cutoffs: thrombocytes <120,000/mL, viremia ≥5 log10/mL, and β2 microglobulin ≥12 mg/L). This recursive algorithm had a negative predictive value of 100% for moderately to severely symptomatic infection.

CONCLUSION

The combination of thrombocytes, β2-microglobulin, and cytomegalovirus viral load in fetal blood can be used for prognosis determination, particularly in cytomegalovirus-infected fetuses without severe brain abnormalities at the time of prenatal diagnosis. Future studies should evaluate whether these parameters remain useful in infected fetuses who have been treated with valacyclovir before fetal blood sampling.

Cost-effectiveness of cytomegalovirus vaccination for females in China: A decision-analytical Markov study

BACKGROUND

The global burden of disease caused by congenital cytomegalovirus (CMV) infection is high. Previous modeling studies have suggested that CMV vaccination may be cost-effective in developed countries. Congenital CMV infection is more likely driven by maternal non-primary infection in China. We aimed to measure the effectiveness and cost-effectiveness of population-level CMV vaccination in Chinese females.

METHODS

A decision tree Markov model was developed to simulate potential CMV vaccination strategies in a multi-cohort setting, with a population size of 1,000,000 each for the infant, adolescent (10-year-old) and young adult (20-year-old) cohorts. The hypothetical vaccines were assumed to have 50% efficacy, 20 years of protection, 70% coverage, at a price of US$120/dose for base-case analysis. Costs and disability-adjusted life years (DALYs) were discounted by 3% per year and the vaccination would be considered cost-effective if an incremental cost-effectiveness ratio (ICER) was lower than 2021 Chinese per capita GDP (US$12,500).

FINDINGS

For the pre-infection (PRI) vaccine efficacy type, the adolescent strategy was the most cost-effective, with an ICER of US$12,213 (12,134 to 12,291) pre DALY averted, compared with the next best strategy (young adult strategy). For pre- and post-infection (P&PI) efficacy type, the young adult strategy was the most cost-effective as it was cost-saving. In one-way analysis varying the PRI vaccine price, the infant strategy, adolescent strategy and the young adult strategy would be a dominant strategy over others if the vaccine cost ≤US$60, US$61-121 and US$122-251 per dose respectively. In contrast, the young adult strategy continued to be the preferred strategy until the P&PI vaccine price exceeded US$226/dose. Our main results were robust under a wide variety of sensitivity analyses and scenario analyses.

INTERPRETATION

CMV vaccination for females would be cost-effective and even cost-saving in China. Our findings had public health implications for control of CMV diseases.

Current practices of management of maternal and congenital Cytomegalovirus infection during pregnancy after a maternal primary infection occurring in first trimester of pregnancy: Systematic review

INTRODUCTION

Congenital CMV infection is the first worldwide cause of congenital viral infection but systematic screening of pregnant women and newborns for CMV is still debated in many countries.

OBJECTIVES

This systematic review aims to provide the state of the art on current practices concerning management of maternal and congenital CMV infection during pregnancy, after maternal primary infection (PI) in first trimester of pregnancy.

DATA SOURCES

Electronically searches on databases and hand searches in grey literature.

STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS

Primary outcome was listing biological, imaging, and therapeutic management interventions in two distinct populations: population 1 are pregnant women with PI, before or without amniocentesis; population 2 are pregnant women with congenitally infected fetuses (after positive amniocentesis). Secondary outcome was pregnancy outcome in population 2.

RESULTS

Out of 4,134 studies identified, a total of 31 studies were analyzed, with 3,325 pregnant women in population 1 and 1,021 pregnant women in population 2, from 7 countries (Belgium, France, Germany, Israel, Italy, Spain and USA). In population 1, ultrasound (US) examination frequency was 0.75/month, amniocentesis in 82% cases, maternal viremia in 14% and preventive treatment with hyperimmune globulins (HIG) or valaciclovir in respectively 14% and 4% women. In population 2, US examination frequency was 1.5/month, magnetic resonance imaging (MRI) in 44% cases at 32 weeks gestation (WG), fetal blood sampling (FBS) in 24% at 28 WG, and curative treatment with HIG or valaciclovir in respectively 9% and 8% patients.

CONCLUSIONS

This systematic review illustrates management of maternal and congenital CMV during pregnancy in published and non-published literature, in absence of international consensus.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019124342.

Hygiene promotion might be better than serological screening to deal with Cytomegalovirus infection during pregnancy: a methodological appraisal and decision analysis

BACKGROUND

Cytomegalovirus infection is the most frequent viral congenital infection, with possible consequences such as deafness, or psychomotor retardation. In 2016, the French High Council of Public Health was mandated to update recommendations regarding prevention of cytomegalovirus infection in pregnant women. We summarize a critical appraisal of knowledge and deterministic decision analysis comparing the current no-screening situation to serological screening during pregnancy, and to hygiene promotion.

METHODS

Screening was defined as systematic serological testing, during the first trimester, with repeated tests as needed, to all pregnant women. Outcomes were: 1) severe sequela: intellectual deficiency with IQ ≤ 50 or hearing impairment < 70 dB or sight impairment (≤ 3/10 at best eye); 2) moderate sequela: any level of intellectual, hearing or sight deficiency; and 3) death or termination of pregnancy. We simulated the one-year course of cytomegalovirus infection in a cohort of 800,000 pregnant women. We developed a deterministic decision model, using best and min-max estimates, extracted from systematic reviews or original studies.

RESULTS

Relevant data were scarce or imprecise. We estimated that 4352 maternal primary infections would result in 1741 foetal infections, and an unknown number of maternal reinfections would result in 1699 foetal infections. There would be 788 cytomegalovirus-related consequences, including 316 foetal deaths or terminations of pregnancy, and 424 moderate and 48 severe sequelae. Screening would result in a 1.66-fold increase of poor outcomes, mostly related to a 2.93-fold increase in deaths and terminations of pregnancy, not compensated by the decrease in severe symptomatic newborns. The promotion of hygiene would result in a 0.75-fold decrease of poor outcomes, related to both a decrease in severe sequelae among symptomatic newborns (RR = 0.75; min-max: 1.00-0.68), and in deaths and terminations of pregnancy (RR = 0.75; min-max: 0.97-0.68).

CONCLUSIONS

Prevention of cytomegalovirus infection during pregnancy should promote hygiene; serological screening should not be recommended.