The intervention focused on starting treatment at an early age to develop the child’s full potential, which is known as early intervention. Given that autistic symptoms and language deficits occur at an early age and affect other areas of development in children with autistic spectrum disorder, we wanted to examine if early intervention is more effective in the reduction in autistic symptoms and language deficits in children aged 36–47 months old when compared to children 48–60 months old. The sample consisted of 29 children diagnosed with ASD who were admitted for integrative therapy. All participants were divided into two groups based on age: G1: 36–47 months old children, and G2: 48–60 months old children. To estimate the presence of autistic symptoms, we used the GARS-3, and for the assessment of speech–language abilities, we used the subscale Estimated Speech and Language Development (ESLD). Our results regarding the effect of the group on the difference in the scores at two time points showed that there was a statistically significant effect of the group on the reduction in autistic symptoms (p < 0.05) but no effect of the group on the differences in speech–language abilities between the two time points (p > 0.05). Our study highlights the importance of emphasizing the exact age when using the terms “early intervention” and “early development” in future studies and practice because it is necessary to determine and establish guidelines about which particular ages are crucial for starting treatment in certain developmental aspects.

Maternal mental health may be considered a determining factor influencing fetal and child development. An essential factor with potentially negative consequences for a child’s psychophysiological development is the presence of maternal distress during pregnancy and the postpartum period. The review is organized and presented to explore and describe the effects of anxiety, stress, and depression in pregnancy and the postpartum period on adverse child developmental outcomes. The neurobiology of maternal distress and the transmission mechanisms at the molecular level to the fetus and child are noted. In addition, the paper discusses the findings of longitudinal studies in which early child development is monitored concerning the presence of maternal distress in pregnancy and the postpartum period. This topic gained importance in the COVID-19 pandemic context, during which a higher frequency of maternal psychological disorders was observed. The need for further interdisciplinary research on the relationship between maternal mental health and fetal/child development was highlighted, especially on the biological mechanisms underlying the transmission of maternal distress to the (unborn) child, to achieve positive developmental outcomes and improve maternal and child well-being.