The Relationship between Cognitive and Physical Development of 5-year-old Children, Conceived through in Vitro Fertilization

The cognitive development of children is closely related to their physical development and health. The scientific interest to identifying the relationships between cognitive and physical development of children born after in vitro fertilization (IVF) is based on the contradictory data about their mental and physical development. Methodological limitations are related to the fact that most studies are cross-sectional and are limited to early childhood, and studies of the relationship between physical and cognitive development have been mostly conducted on a sample of children not selected by conception method. The aims of this study were: to identify the characteristics of the cognitive and physical development of children aged 5 years conceived through IVF and to assess the relationship between their cognitive and physical development. The data were collected from the families participating in the Prospective Longitudinal Interdisciplinary Study of child development when their children reached the age of 5 years. The sample included 81 children conceived through IVF and 130 children conceived spontaneously. The Parent-Administered PARCA and Parent-reported PARCA were used to diagnose cognitive development and cognitive motivation, and the questionnaires by the Quebec Longitudinal Study of Child Development research group were used to diagnose sleep, nutrition, physical development, and health. Children conceived through IVF demonstrated significantly higher levels of general knowledge, experienced fewer feeding difficulties, went to bed at an earlier time, and suffered less skin infections compared to the control group. Girls conceived through IVF had a lower body mass index (BMI) compared to spontaneously conceived girls. In families who conceived children through IVF, significant correlations of sleep duration, feeding difficulties and BMI with indicators of cognitive development were observed.