The prevalence of gestational diabetes mellitus (GDM) continues to rise worldwide, reaching 10–20% among pregnant women in Russia. GDM not only complicates the course of pregnancy but is also associated with changes in the woman’s emotional state, which affects her attitude toward pregnancy, childbirth, and the formation of her relationship with the child. Understanding the nature of these changes requires studying the specific features of women with GDM, comparing them with those without carbohydrate metabolism disorders, and examining the relationship between emotional state and maternal attitudes toward the child. The aim of this study was to investigate the characteristics of emotional state, maternal attitude, and mother–child interaction during pregnancy in women with gestational diabetes mellitus. The participants were 47 women aged M (SD) = 32 (6) years at 28.5 (6.3) weeks of gestation, including 19 with GDM and 28 without carbohydrate metabolism disorders. The following tools were used: Beck Anxiety Inventory, Beck Depression Inventory, Edinburgh Postnatal Depression Scale, Test of Attitudes of Pregnant Women, Maternal Antenatal Attachment Scale (MAAS), and a socio-demographic questionnaire. The results showed that women with GDM, compared to women without GDM, had higher scores on the behavioral component of maternal attitudes toward the child during the prenatal period and a less pronounced depressive type of attitude toward pregnancy. Correlations between anxiety, depression, and maternal attitudes toward the child were more harmonious in women without GDM, whereas in women with GDM, they reflected greater tension and a stronger bodily-affective orientation. Women with GDM more often perceived fetal movements as active and endowed them with emotional meaning, which may indicate a compensatory enhancement of orientation toward the child against a background of emotional vulnerability. These findings highlight the importance of comprehensive care for pregnant women with GDM, including psychological support and regular monitoring of emotional well-being.