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Study on Valaciclovir to Prevent Congenital CMV Infection in Pregnant Women with First Trimester CMV Infections

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying congenital CMV infection, a condition caused by the cytomegalovirus that can be passed from a pregnant mother to her baby. The study is investigating the use of a medication called Valaciclovir, which is taken as a film-coated tablet. The purpose of the study is to explore how effective Valaciclovir is in preventing the transmission of CMV from mother to baby during pregnancy, specifically when the mother contracts the virus for the first time in the first trimester.

Participants in the study will take Valaciclovir orally. The study will monitor the health and safety of both the mother and the baby throughout the pregnancy and after birth. This includes regular check-ups using ultrasound and MRI scans to look for any signs of the virus being passed to the baby. Blood tests will also be conducted to ensure the safety of the mother and baby, checking important health indicators like liver and kidney function. After birth, the baby's health will continue to be monitored, including hearing tests and developmental assessments up to five years of age.

The study aims to provide valuable information on whether Valaciclovir can help prevent the transmission of CMV during pregnancy, potentially offering a new way to protect babies from this infection. The trial is expected to continue until 2031, allowing researchers to gather comprehensive data on the long-term effects and benefits of using Valaciclovir in this context.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Consent and enrollment

    Provide voluntary written informed consent. This confirms understanding and agreement to participate in the study.

    Ensure eligibility by being 18 years or older and having a confirmed first trimester primary CMV infection.

  2. Step 2

    Medication administration

    Begin taking valaciclovir as prescribed. The medication is in the form of a 500 mg film-coated tablet.

    Take the medication orally as directed by the study team. Follow the dosage and frequency instructions provided.

  3. Step 3

    Monitoring and assessments

    Undergo regular monitoring to assess the rate of vertical transmission. This includes a CMV PCR test on amniotic fluid collected during an amniocentesis at 20 weeks of pregnancy.

    Participate in imaging assessments, including ultrasounds every two weeks and an MRI at 30 weeks of gestational age.

  4. Step 4

    Safety evaluations

    Maternal safety will be assessed through blood tests to check hematology, liver function, and kidney function.

    Fetal safety will be evaluated through prenatal ultrasounds, blood analysis at birth on umbilical cord blood, and a postnatal urine sample.

  5. Step 5

    Postnatal assessments

    After birth, a PCR test will be conducted on a urine sample to reconfirm the results of the amniocentesis.

    An MRI will be performed postnatally to check for any abnormalities.

  6. Step 6

    Long-term follow-up

    Hearing assessments will be conducted yearly until the child reaches four years of age.

    Neurodevelopmental follow-up will occur at 1, 2, and 5 years of age to monitor the child's development.

Who can join the trial?

4 criteria

  • The participant must provide voluntary written informed consent, which means they agree to join the study after understanding all the details.
  • The participant must be 18 years or older.
  • The participant must have a proven first trimester primary CMV infection. This means they have been diagnosed with a new CMV infection during the first three months of pregnancy.
  • The participant must be female.

Who cannot join the trial?

6 criteria

  • Patients who are not pregnant cannot participate.
  • Patients who are not in their first trimester of pregnancy cannot participate.
  • Patients who do not have a primary **CMV infection** during pregnancy cannot participate. CMV infection is a virus that can be passed from mother to baby during pregnancy.
  • Patients who are male cannot participate.
  • Patients who are not within the specified age range cannot participate.
  • Patients who are not considered part of a vulnerable population cannot participate. A vulnerable population includes groups who may be at higher risk of harm or exploitation.
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Investigated drugs

Valaciclovir is a medication used in this clinical trial to help prevent the transmission of a virus called CMV from a pregnant mother to her unborn baby. CMV is a common virus that can cause health problems for the baby if passed on during pregnancy. Valaciclovir works by stopping the virus from multiplying, which can reduce the chance of the baby getting infected. This study is looking at how well valaciclovir works when given to pregnant women who have a new CMV infection in the early stages of pregnancy.

What is already known about the treatment

Valaciclovir – Valaciclovir is administered orally in the form of tablets. It is currently being studied for its effectiveness in preventing the transmission of congenital cytomegalovirus (CMV) infection from mother to child during pregnancy. The main therapeutic indication for valaciclovir in this study is to prevent vertical transmission of CMV when the mother contracts the virus in the first trimester. At the molecular level, valaciclovir works by inhibiting the replication of viral DNA, which helps to reduce the spread of the virus in the body. It is classified as an antiviral medication.

Investigated diseases

Congenital Cytomegalovirus Infection – Congenital cytomegalovirus infection occurs when a baby is infected with the cytomegalovirus (CMV) before birth. This virus is a common cause of infection in humans and can be transmitted from a pregnant woman to her fetus. The infection can affect the development of the baby, potentially leading to hearing loss, vision problems, or developmental delays. The virus can be present in the baby's body without causing any symptoms at birth, but some infants may show signs such as jaundice, low birth weight, or an enlarged liver and spleen. Over time, the virus can continue to affect the child's health, particularly their hearing and neurological development. Monitoring and follow-up are important to assess the long-term effects of the infection on the child's growth and development.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-500714-25-01Estimated enrolment112 patientsSponsorUZ Leuven

sourced from the EU Clinical Trials Register and site verification

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