Purpose of study. Estimation of efficiency of application of BIOPTRON phototherapy for treatment of placental insufficiency (PI) in pregnant women with 1 type diabetes mellitus (DM1) in conditions of ecological trouble. Methods. Two groups of supervision were formed: the I group - 42 pregnant women with DM1 who received phototherapy “BIOPTRON”; the II group - 57 pregnant women with DM1 who did not receive phototherapy (the control group). Efficiency of the carried out therapy was estimated with the use of the markers of blood serum morphology. All received materials were subjected to statistical processing with given reliability 95 % or significance value (p) 0.05. Results and conclusions. In the 1-st group of the women with DM1, the outcomes of pregnancy were more favorable both for the mothers and for the fetuses. Almost 7 times less often, pregnancy was terminated in the second trimester (p < 0.01 less often), premature births occurred 2 times less often, diabetic fetopathy developed 3.3 times less often as well as fetus chronic intrauterine hypoxia, placental insufficiency occurred 2 times less often (OR - 0.42, RRR - 76 %, NNT - 1.31). Pregnancies complicated with heavy forms of toxemia of pregnancy occurred also much less often (OR — 0.12, 95 % CI 0.06 — 0.2, p = 0.003) in comparison with the control group. Outcomes of the deliveries of the pregnant women with DM1 receiving phototherapy indicated positive influence of light waves BIOPTRON on homeostasis.