First in the World
After her friend contracted the virus in the early stages of pregnancy, Dr. Keren Shachar-Nissan, senior physician in the Emergency Medicine Department at Schneider Children's, initiated and led a study to find effective preventive care for fetal CMV. The study was conducted in collaboration with the Women's Hospital at Beilinson and the report will be published in the prestigious medical journal The Lancet.
The research, conducted by doctors in Schneider Children's and in the Pre-Natal Unit, headed by Prof. Eran Hadar at the Rabin Medical Center, investigated the effectiveness of the drug valacyclovir to prevent CMV infection in the fetus following primary infection of the mother during pregnancy. The cohort comprised 100 women who were infected with the virus at the beginning of their pregnancies and who were referred to the pre-natal infection clinic headed by Prof. Yaacov Amir and Prof. Yosef Pardo, internationally-renowned specialists in the field. Also participating in the research were Prof. Arnon Viznitzer, Director of the Women's Hospital at Beilinson, Prof. Efi Bilavsky, Prof. Irit Krause and Dr. Orit Peled.
The women were treated with the drug valacyclovir or a placebo until they underwent an amniocentesis, which revealed whether the fetus was infected with the virus. The research was conducted anonymously. The study found that if the drug valacyclovir is administered as early as possible from the moment of the mother's infection, the rate of fetal infection is reduced by 71%. The research was accepted for publication in the renowned journal The Lancet, which will be issued in the coming weeks. Because of the significance of the research results and its potential for preventive care, there is a clear need to conduct a broader investigation of pregnant women infected with the virus.
CMV is the most common birth infection with an incidence of 1% in all births. Most of the infections that cause significant harm to the fetus result from the mother's primary infection during pregnancy. Following maternal infection, 30-40% of fetuses become infected with the virus. The greatest danger of injury to the feturs is when maternal infection occurs during the first trimester or close to the time of conception. Fetal infection can lead to serious injury of multiple systems such as microcephaly, pre-ventricular brain calcification, intrauterine delayed growth, enlarged spleen and liver, lethargy, chorioretinis (inflammation of the retina), and metabolic disorders such as anemia and thrombocytopenia. The most severe injury to the fetus is neuro-developmental expressed by deafness and vision disorders including blindness. Hearing disorders may not necessarily appear at birth but only later in the child's first years of life, even among those who are asymptomatic. In cases of maternal primary infection during pregnancy, it is usual to wait until an amniocentesis to check if the fetus has been infected. If confirmed, there is close follow-up of the pregnancy at risk with a recommendation to stop the pregnancy if results confirm a symptomatic fetus.
Dr. Shachar-Nissan: "Waiting with arms folded until the amniocentesis without any possibility of intervention and treatment was unacceptable to me in the world of medicine today. Up till now, no treatment has proven to be effective to prevent the spread of the virus to the fetus after the pregnant mother's infection. Our study will promote effective preventive care that will significantly reduce fetal infection, which in turn will reduce the serious harm that the virus can cause, and also the need to halt the pregnancy due to fetal morbidity."
Prof. Viznitzer said, "This represents a breakthrough that can provide a response to many women who until now had to stop the pregnancy."
Prof. Pardo noted that the research, which showed a 71% drop in incidence during fetal development and after birth, will change the complex management required till now of CMV.
There are not yet any regulations in place to conduct a CMV review at the beginning of every pregnancy or prior to pregnancy. This is because, until now, there was no way to prevent maternal infection spreading to the fetus. Because the research showed the effectiveness of preventive care, there is a clear indication for a universal survey to be conducted, in order to identify maternal infection as early as possible and initiate drug treatment.