The "placental barrier," it now is clear, actually operates as a thoroughfare for substances that may help or hinder both fetus and mother.
Human and animal studies indicating new aspects of this critical interaction were presented at several recent meetings. They included evidence that:
Women having chickenpox during late pregnancy can, in fact, transfer immunizing levels of antibody tb their fetuses;
Fetal thymic hormone can maintain immunologic competence and forestall the "wasting syndrome" (runting) in pregnant, thymectomized mice.
Neonatal chickenpox (varicella) sometimes has been found to occur among infants of mothers infected during pregnancy. Within the first ten days of life, the mortality from congenital infection is 20%, said Philip A. Brunell, MD.Because the mechanisms of infection were obscure, such cases have raised doubts that maternal antibody against varicella could protect the fetus by transplacental passage as can occur with measles, for example."Laboratory studies have not