The scientific work is dedicated to the prevention of perinatal morbidity and mortality in heart rhythm disturbances in fetuses, based on the study of the characteristics and patterns of arrhythmias, by means of instrumental and laboratory research methods. The prevalence of fetal cardiac arrhythmias, the risk factors of their development, CTG and Doppler patterns in fetuses with cardiac arrhythmias were studied. It was found that the risk factors for the fetal cardiac arrhythmias are as follows: tobacco smoking, SARS, intake of drugs, such as NSAIDs, antihypertensives, antibiotics and anti-depressants in the 1st trimester of pregnancy, the factors leading to changes in water-electrolyte balance, psycho-emotional overload, hypothermia, hyperthermia, and occupational hazards. It was proved that the application of proposed treatment in appropriate time frame provides positive effect on the fetus and its vitality, but also helps to prolong a pregnancy to the term, thus decreasing the number of additional neonatologic procedures needed to care the newborns. Significant positive effect of the use of drug therapy in women with fetal cardiac rhythm disorders during the prenatal period has been proved by obtaining the following results: sinus rhythm disturbances decreased from 35 % to 8,75 %; extrasystole - from 44 % to 12,5 %; supraventricular tachycardia - from 11 % to 5 % ± 2,4 %; atrial flutter - from 4 % to 2,5 % and complete AV block - from 6 % to 3,75 %. It was found that consequences of fetal arrhythmias were favorable in sinus rhythm disturbances. They were considered as relatively favorable if the tachy- and bradyarrhythmias (depending on the etiology and time of manifestation, the presence of congenital malformations, etc.) and absolutely unfavorable in case of fetal hydrops. It was also found that the use of the proposed treatment was most effective in case of sinus rhythm disturbances and extrasystoles. Fetal supraventricular tachycardia, atrial flutter and complete transverse blockade were prognostically unfavorable, as accompanied by nonimmune fetal hydrops in 68 % and 29 % of cases, fetal and early neonatal death of the fetus were observed in 32 % and 29 %, respectively. The algorithms developed and implemented for monitoring and treatment of women with fetal cardiac arrhythmia on the basis of complementary methods of investigation of the fetus: fetal echocardiography, CTG and Doppler control showed their high efficiency. The use of proposed treatment and the appropriate timing of administration provide positive effects to the fetus and also help in pregnancy prolongation and improve neonatal care.
