Introduction Gestational diabetes mellitus (GDM) is a risk factor for both mother and child, both in the short term (peripartum morbidity) and in the long term (development of postpartum diabetes or fetal programming). In the Czech population, given the standard of care for pregnant women with GDM, we have so far limited information on the development of offspring of women with GDM in index pregnancy. Methodology A total of 615 women (n = 322 controls with a physiological course of index pregnancy and n = 292 women with a history of GDM dg. According to IADPSG criteria) were contacted, who gave prior consent to repeated contact, to fill in an electronic questionnaire focused on basic parameters monitoring the child's development from birth to five years of age. All parameters were obtained exclusively from the child's medical card (weight, height, head circumference, psychomotor development, morbidity, need for medication / hospitalization, need for specialist monitoring), as well as vaccination status and lactation time. Of the total number of interviewed questionnaires, 89 (14%) were filled in by women (26 GDM and 63 inspections). We evaluated the differences between the children of women with and without a history of GDM. The following parameters were monitored in mothers: age, BMI, weight gain during pregnancy, diabetes (DM) in the family, smoking, parity, overweight / obesity. Results Healthy mothers had lower BMI and smoked less than women with GDM (both P = 0.02, chi-square test). Furthermore, statistically significant differences were found during childbirth (more complications after childbirth in women with GDM, P = 0.035 chi-square test), children of mothers with GDM were significantly later and spoke less (P = 0.01 for the first words and P = 0.003 for joining words, chi-square test). Conclusion Compliance of respondents was relatively small (approximately 14% of all respondents, which, however, corresponds to the global scale), however, from the obtained results it can be concluded that between the children of women with GDM and without GDM are not significant differences in our group. From the available data, it seems that the use of IADPSG criteria for the diagnosis of GDM (essentially tightening the cut off for fasting blood glucose) is also appropriate from the point of view of the diabetic mother's child. The work was supported by grant 16-28040A of the Internal Grant Agency of the Ministry of Health of the Czech Republic.