Ultrasound assessment of embryo cardiac function as a predictive criterion of adverse pregnancy outcome

Purpose to evaluate the value of the embryo/fetus heart rate (HR) in early pregnancy assessed by ultrasound for the formation of a group at high risk of adverse pregnancy outcomes. Materials and methods. A retrospective analysis of ultrasound examinations of 1073 pregnant women at 5 +0 –10 +6 weeks was carried out. The embryo/fetus heart rate was compared with the gestational age calculated by the crown rump length (CRL) and the date of the last menstruation period (LMP). Retrospectively, all examined pregnant women were divided into two groups: group 1—with intrauterine embryo death before 14 weeks of pregnancy (n = 107); group 2—with prolongation of pregnancy until the second trimester (n = 966). When analyzing the data array using a decision tree, the embryo heart rate was assessed at various stages of pregnancy by LMP, CRL, and regardless of the exact period of pregnancy. Results. Analysis of heart rate values at different stages of pregnancy by LMP showed significant differences in heart rate between groups, the cases of later embryo loss characterized by lover heart rate values. There were no significant differences in heart rate between the groups at different stages of pregnancy by CRL (significant differences were obtained only at 8 +0 –9 +6 weeks). Cut-off values of embryo heart rate for prediction of adverse pregnancy outcomes have been proposed for different stages of pregnancy, as well as a universal cut-off for the entire embryonic period. Conclusion . The proposed cut-off values of embryo heart rate for different stages of pregnancy, calculated by LMP, may be used for timely prediction of adverse pregnancy outcomes. When the exact gestational age is unknown, a universal heart rate cut-off value of <116 bpm may be used. All proposed HR cut-off values were characterized by high specificity, but none of them by high sensitivity. A sensitivity of HR cut-off values can be increased by the use in combination with other ultrasound and clinical signs of adverse pregnancy outcome.