Attention Deficit Hyperactivity Disorder (ADHD) is a widespread chronic childhood illness characterized by hyperactivity, inattention / distractivity and impulse.
In about half of the children, mental deviations persist into adulthood. Compounded by the fact that in parallel with ADHD, such children still have concomitant mental disorders. Many of them need intensive treatment, many need social assistance.
However, the reasons for the development of ADHD are not fully understood. One of the theories claims that the basis of such disorders is laid still in utero, due to hypoxic conditions of the fetus. To verify this thesis, a large-scale study was conducted in the USA, the description of which we offer below.
Organization of the study
464,317 medical records of children born in Kaiser Permanente Southern California in the period 1991-2005 were taken for analysis. The main criterion for the selection was the birth of a child no earlier than 28 weeks, deeply premature babies were not taken into the sample. Unproven cases of ADHD were also excluded from the study, which significantly increased the statistical reliability of the results.
As a result, it was possible to compose a group of 13,613 children who were treated for ADHD at the age of 5-11 years. The control group consisted of 68,065 of their healthy peers (at the rate of 5 children without ADHD per child with such a diagnosis).
Subsequently, 1.5% of children from the control group were also diagnosed with ADHD (1000 patients).
Results and conclusions
Omitting painstaking statistical calculations, the study organizers report that they were able to track the link between the increased risk of developing ADHD and ischemic risks in the fetus.
The most powerful were the following:
- Apgar score less than 7 points 5 minutes after birth;
- the need for resuscitation;
- pelvic or transverse presentation at the time of the onset of labor;
- entwining the neck with an umbilical cord;
- severe gestosis, eclampsia in the mother.
Researchers were unable to establish a relationship between situations with early placental abruption and the development of ADHD.
Overall, among children with ADHD, 24% experienced hypoxic conditions in the antenatal period. In the control group, without mental deviations, ischemic events were observed in 20.9%.
These figures make it possible to assert the effect of fetal ischemia on the risk of subsequent development of a hyperactivity disorder / attention deficit disorder in a child.
However, there is no evidence to suggest that hypoxia is the only risk factor for ADHD. Which once again confirms the polyetiology of this pathology.