Prenatal testing for inherited immune deficiencies by fetal blood sampling.

We attempted to develop a prenatal diagnosis in fetuses at risk for immunodeficiency by fetal blood sampling performed under fetoscopy at 18-22 weeks of gestation. In order to obtain normal values, we first investigated thirty-five control fetuses whose blood punctures were undertaken for the diagnosis of haemoglobinopathies. Surface markers and in vitro mitogen-induced proliferation of the fetal lymphocytes were studied using micromethods. We then examined two fetuses at risk for two different types of severe combined immunodeficiency and established their immunological integrity, hence avoiding an unjustified termination of pregnancy. This immunological integrity was confirmed after birth.