[The significance of cytotoxic activity of maternal lymphocytes for the etiology of intrauterine growth retardation].

Natural lymphocyte cytotoxicity of 99 pregnant women delivering intrauterine growth retarded (IUGR) babies was compared to that of 460 women with normal pregnancies. Lymphocytes separated from maternal blood were used as effectors in the in vitro cytotoxicity test using human embryonic fibroblast cells as target. The cytotoxicity test was based on the assessment of endogenous alkaline phosphatase activity of the target cells. A definite shift towards IUGR pregnancies was observed in the distribution of patients when analyzed according to step by step increase of lymphocyte cytotoxicity values. The incidence of increased cytotoxic activity (greater than or equal to 40%) was three times higher in the group of women with IUGR pregnancies than that in the control group. Within the group of women showing increased immunoreactivity during pregnancy the participation of IUGR pregnancies was 40.4%, while only 9.7% of the women with normal cytotoxicity belonged to the IUGR group. Combined analysis of ponderal indices and cytotoxicity values suggests that increased immunoreactivity is associated with a nutritive insufficiency resulting in the disproportionate form of IUGR.